I 

Health Hazard 

Evaluation 

Report HErA 84-477-1824 

BUNGE CORPORATION 

DECATUR_, ALABANL\ 
,.
 ' 


HETA 84-477-1824 NIOSH INVESTIGATORS: 


AUGUST 1987 Sara Arnold , M.D . 
 BUNGE CORPORATION Michael S. Crandall, CIH 


DECATUR, ALABAMA 


I. SUMMARY 

In August 1984, the National Institute for Occupational Safety and 

Health received a request from the Oil, Chemical and Atomic Workers 

Union Local 3-906, to evaluate symptoms of respiratory irritation and 

skin rashes among employees exposed to soybean dusts at the Bunge 

Corporation in Decatur, Alabama . Medical and environmental surveys 

were conducted by NIOSH in February and March 1985. 

Worker exposures to the soybean dusts were categorized into four 

components: raw dust, cleaner dust, extracted dust, and mixed dust. 

Total and respirable dust samples were collected. The range of total 

dust exposures in the raw soybean dust category was 0 . 16 to 22.6 

mg/m3 for 34 workers. The average for all samples was 3.73 rng/rn3 . 

The ACGIH TLV for grain dusts is 4 ~/m3 total dust. The OSHA PEL 

for nuisance particulates is 15 mg/m for total dust. One utility 

worker performing cleanup in the head house was exposed to nuisance 

dust at a level near the OSHA PEL (14.7 mg/m3), and another was 

overexposed (22.6 mg.m3). Si x bean barge workers had dust e~osures 

exceeding the ACGIH TLV, and one worker's exposure (14 . 2 rng/m ) 

approached the OSHA PEL~ The use of respiratory protection was at the 

discretion of the worker in all plant areas. 

Respirable raw dust exposures ranged from 0.02 to 1.02 rngtm3 and 

averaged 0.26 mg/m3 for 35 samples . Bean barge cleanup workers and 

utility workers in the head house had the highest average respirable 

exposures at 0.45 and 0.42 mg/m3 , respectively. 

The total dust exposure results for workers in the cleaner soybean dust 

category ranged from 0.18 to 0.72 mg/m3 and averaged 0 . 48 mg/m3 for 

13 samples. The respirable dust results ranged from 0.01 to 0.15 

mg/m3, with a mean of 0.08 mg/m3 . This was the lowest exposure 

category for the soybean dusts. 

The total dust exposure sample results for the extracted soybean dust 

category ranged from 0.18 to 15 . 0 mg/m3 and averaged 2 . 28 mg/m3. 

One exposure, to a worker loading rail cars with soybean meal , equaled 

the OSHA PEL of 15 mg/m3 . Respirable dust exposures r anged from 0.02 

to 0.38 mg/m3 and averaged 0.11 mg/m3 . 

Six samples, col lected from worker s who received a mixed exposure t o 

soybean dusts, ranged from 0.76 to 16 . 2 mg/m3, and the mean was 5 ./7 

mg/m3. The higher exposures were to workers who transferred from 

jobs in the mea l house to hel p s e t up or clean out bean barges. 
Three of these exposures exceeded the ACGIH TLV, and one of them 

exceeded the OSHA PEL . tiespirabie mixed dust exposures ·canged from 

0.06 to 0 . 4; mg/m3 an~ averaged 0.~3 mg/m3. 

The medical survey demonstrated a high prevalence of work- related lower 

respiratory symptoms, although medical evaluations did not confirm 

these symptoms, pathophysiologically, to have been asthma. A 

substantial majority of the symptoms were reported to be related to raw 

soybean dust exposure. A high prevalence of work- related rhinitis was 

also found, similarly reported to be related to raw soybean dust 

exposure. 

High personal exposures to soybean dusts occurred in the shipping and 

receiving areas of the plant, presumably to the raw and extracted 

dusts. · Utility workers in general had high exposures to soybean 

dusts. Lower-respiratory tract symptoms were prevalent among exposed 

workers. Engineering controls and an improved respiratory protection 

policy are recommended. 

KEYWORDS : SIC 0723 (crop preparation services for market) 

soybean dust, asthma, rhinitis, bronchitis, allergy 

( 
Page 3 - Health Hazard Evaluation Report No HETA 84-477 

II. INTRODUCTION 

In August 1984, the National Institute for Occupational Safety and 

Heal.th received a request from the Oil, Chemical, and Atomic Workers 

Union Local 3-906, to evaluate symptoms of respiratory irritation and 

skin rashes among employees of the Bunge Corporation's Decatur, Alabama 

plant. An initial walk-through survey was conducted in October 1984, 

and a preliminary questionnaire survey was conducted in January, 1985. 

A follow-up medical and environmental survey was conducted in February 

1985. Since unexpected freezing weather caused malfunction of some of 

the industrial hygiene monitoring equipment, invalidating results for 

one day's monitoring, the industrial hygiene and. pulmonary function 

testing from this visit were discarded, and those components of the 

evaluation were re-scheduled for the final survey, in March 1985. Each 

participant in the medical survey was notified of the results of his 

medical testing in March 1986. At that time, both company and union 

representives were informed of preliminary conclusions and 

recommendations, based upon an examination of the data from the medical 

survey. 

I II. BACKGROUND 

At the time of this evaluation, the Bunge Corporation was the 

third-largest grain-handling company in the world. The Decatur, 

Alabama plant was operated by Goldkist from 1974, when the plant was 

opened, until it was purchased by Bunge in 1982. At the time of the 

study, Bunge employed 72 hourly workers. 

Soybeans are received by rail.car, truck, and/or barge, and conveyed to 

the head house, where they are distributed to storage, drying, or 

processing areas of the plant. In the processing/prep area the 

soybeans are cleaned, dried, and cracked to loosen the seed coat or 

hulls. Then they are dehulled, flaked, and transferred to the 

processing/extraction area, where the oil is extracted using hexane in 

a stationary-basket extractor. The spent flakes are desolventized, 

toasted, processed as meal by cooling, grinding, and screening, and 

then sent to the meal house for s t orage and disposition. Soybean meal 

is shipped from the plant by railcar and truck. The hexane solvent is 

recovered from the extracted oil, which is then stored for shipping. 

Soybean oil is shipped from the plant by truck and barge. A typical 

process diagram is pictured in Figure 1. 

The workers are divided among the Shipping and Receiving, Processing, 

! 

and Maintenance departments. Workers in all of these departments have 

potentia.l exposures to soybean dusts. The primary differentiation to 

be made among the dust exposures is whether the source is unprocessed 

or processed soybeans. The unprocessed (raw bean) dust will contain 

foreign materials such as hulls, dirt, fungal spores, and insect 

parts. Processed soybean dusts, which are "cleaner", are generated. 

after the beans 'nave been dehulled or extracted. 
Page Li - Health Hazard Evaluation Report No HETA 84-477 

~enerally speaking, worker expo;;ur·es to t·aw ::;oyl>ean dust will occur 

during unloading of raw soybeans (from barges, trucks, and railcars), 

work in the head house and storage tanks , or as a maintenance mechanic 

in these areas. The exposures to processed soybean dust would occur in 

the prep building, the meal house, the truck and railcar loading area, 

or as a maintenance mechanic in these areas. Mixed exposures are not 

uncommon since workers move around during a shift according to staffing 

needs. For example, during the NIOSH evaluation, second shift workers 

from the meal house also did cleanup work inside a bean barge at the 

harbor, resulting in exposure to both processed and raw soybean dusts. 

Because of the potential for exposures to the various dusts, the 

company provided 3M Model 3710 single-use respirators. In the 

extraction process area there were self-contained breathing apparatus 

and air-line respirators for emergency use. Negative pressure organic 

vapor cartridge respirators were also provided for the extraction 

operators. · 

IV. EVALUATION DESIGN AND M.F.THODS 

A. Environmental 

Environmental air sampling was conducted beginning with the third 

shift on March 3, 1985, and concluding with the first shift on 

March 6, 1985 . Personal breathing-zone samples were collected so 

that individual dust exposures could be matched with medical 

results. Workers from each exposure category were monitored during 

the course of two workshifts where possible. Total dust and 

respirable dust breathing- zone samples were collected from each 

worker monitored. 

1. Total Dust 

Personal total dust samples were collected on tared 37-rnm, 5-um 

PVC membrane filters at a nominal flow rate of 2 liters per 

minute (lpm) . Gravimetric analysis was performed on the 

collected samples. The instrumental precision of the weighings 

was 0.01 mg (NIOSH Method 0500).l 

2. Respirable Dust 

Respirable dust samples were collected on tared 37-mm, 5-um PVC 

membrane filters mounted in 10-mm Dorr-Oliver cyclones. Air 

was drawn through the filter at a flow rate of 1.7 lpm. 

Gravimetric analysis was performed on the collected samples. 

The instrumental pre~ision of the weighings was 0.01 mg (NIOSH 

Method 0600).1 
Page 5 - Health Hazard Evaluation Report No HETA 84-477 

B. 	 Medical 

Available resources limited the medical study to 50 persons, so not 

all employees could participate. The following employees were 

excluded because they constituted gender, age, or employment 

categories too small for valid comparison with other groups of 

employees: (1) three women, (2) four employees with dates of birth 

prior to 1930, and (3) three employees with less than three years 

duration of employment. Three other employees were excluded 

because they had non-occupational medical conditions identified by 

a screening questionnaire administered in January 1985. Fifty of 

the remaining 59 eligible employees were chosen to approximate 851.;,,.... 

of eligible employees from each department. During the February 

visit, some employees who had been chosen for the study group were 

on leave or did not want to participate. When available, 

substitutions were made from the same department. When there were 

no. eligible employees rema1n1ng from a department, any eligible 

employee was added to the study group to keep the total at 50 

persons. 

During the February 1985 visit, medical interviews for 48 of the 50 

participants were completed. A NIOSH interviewer administered a 

questionnaire that inquired about demographic characteristics, 

acute irritant symptoms, symptoms associated with diseases of the 

upper and lower respiratory tract, personal and family medical 

history, smoking habits, and jobs prior to working at Bunge. The 

participant was then seen by a NIOSH physician who , without knowing 

his past or current jobs at Bunge, reviewed the questionnaire 

responses to assess whether he met pre- determined criteria for 

be.ing considered a case of possible asthma and/or possible 

rhinitis. These were: 

(1) 	Possible asthma: Any of the following symptom sets during 

the last year: 

wheeze and chest tightness, 


wheeze and shortness of breath, 


chest tightness and shortness of breath, 


chest tightness and cough, or 


wheeze brought on by exercise or cold. 


{ 

(2) 	Possible rhinitis: Any three of the following symptoms, at 

least one of which involved itching, during the last year: 

runny nose, frequent sneezing, itchy nose, itchy watery 

eyes, stuffy nose, and itching in the roof of the mouth and 

throat. 
Page. 6 - Health Hazard Evaluation Report No HETA 84- 417 

Tht physician was instrcct~d to ev:iluate positive responses i>efore 

classifying •~mployecs as possible asthma or rhinitis. For example, 

a positive questionnaire response to .. wheezy or whistling 

breathing" would not be counted as wheezing if the physician 

determined that the employee was refert:"ing to whistling breathing 

from a stuffy nose. 

The phy_sician was then instructed to determine if the possible 

asthma and/or rhinitis was temporally related to occupation. 

Possible occupational asthma or rhinitis cases were possible asthma 

or rhinitis cases that met all four of the following criteria: 

(1) onset of symptoms since beginning employment at Bunge, 

(2) symptoms that "never" or "seldom" occurred following 

certain activities or after exposure to specific materials at 

home , 

(3) symptoms that occurred "sometimes" or "most times" during 

or after specific jobs at work, and 

(4) symptoms that occurred less frequently on vacation and on 

days away from work than on workdays. 

Finally, a second NIOSH physician interviewed the employee 


regarding his present and past jobs at Bunge. 


The Karch 1985 medical survey included pulmonary function tests and 


allergy tests. Also, the questionnaire was administered to the two 


individuals who were on leave during our Februar·y visit. 


A NIOSH physician administered skin prick tests using preparations 

of common allergens and various fractions of raw soybeans and 

soybean products. Blood samples were drawn for determination of 

serum concentrations of (a) total immunoglobulin E (IgE), and (b) 

IgE specific to the soybean fractions and products by 

radioallergosorbent test (RAST) (Table 9). A skin test reaction 

was classified as positive if the wheal was 2 mm in diameter and a 

flare was present. The RAST was defined as positive if the percent 

binding of IgE antibody was greater than three times the mean 

binding of a negative control. For a given allergen, the skin / 

prick test should be more sensitive than the RAST test, that is, 

the skin prick test should more often be positive in the presence 

of allergy, or should be positive earlier in the time course of the 

allergy, than the RAST. Though more specific for hypersensitivity 

to an allergen tha.n skin. prick tests, a RAST may also be positive 

in the presence of elevated total serum IgE antibody levels, due to 

non-specific binding of IgE to the product tested. 
Page 7 - Health Hazard Evaluation Report No HETA 84-477 

Pulmonary function testing consist ed of spirometry and peak 

expiratory flow rate (PEFR) measurements. On retur:n to work aft

two days off, pre- and post-shift spirometry was performed with 

Ohio Medical Model 822 dry ro l ling seal spirometer. On the last

day of each employee's work week, post-shift spir·ometry was 

performed. One-second forced expiratory volume (FEV ) and force 1

vital capacity (FVC) were measur:-ed in accordance with the Americ

Thoracic Society's criteria for screening spirometry.2 Predicte

values for FEV and FVC were calculated using the equations of 1 

Knudson, et al.3 The Knudson values were multiplied by 0.85 to 

obtain the predicted values for Blacks. 

Employees were insteucted in the use of a mini-Wright portable 

flow meter and asked to record peak expiratory flow rate and 

symptoms every three hours whil e awake for seven consecutive da

On each day for which data were available, for each participant,

the difference between maximum and minimum PEFR was calculated 

percentage of maximum PEFR. I f that percent difference exceede

percent, then the individual was i dentified as having reversi bl

airways obstr:uction. 

On the days that individuals had pre- and post-shift spirometry

testing, industrial hygiene monitoring was performed for person

respirable and total dust . 

Pulmonary function tests and job history 

To examine the relationship between medical outcomes such as sympto

and pulmonary function test changes, and job category and job histo

we defined organic dust categories according to stages of processin

undergone by the soybeans. The various tasks performed by employee

were categorized into four "organic dust exposure" categot"ies. 

"Raw" dust: All tasks involving exposut"e to soybeans and soybe

dust prior to the soybeans being de- hulled , e.g., 

unloading raw soybeans (from barges, trucks and railcars), 

tasks in the storage tanks , head house, and the tunnels wh

connect the storage tanks to the head house, 

loading hulls , or 

utility and maintenance work on the r..racking rol.ls, on the 

first floor of the prep buildi.ng (where a conveyor systP.m 

beings unprocessed whole soyb.. ans to the peep house) , and 

the above areas. 

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Page 8 -· Health Hazard Evaluation Report No HETA 84-4 77 

"C li;:aner" procdssed dust: :.11 task:; i.n the prep bt,;ilding, 

including utility and maintenance work (except those on the first 

floor or involving the cracking rolls). 

"Extracted" processed dust: All tasks iuvolving exposure lo meal 

(i.e. , soybean product after the extraction process), including 

loading railcars and trucks with meal, working in the meal house 

control room, and all utility and maintenance work in the meal 

house, truck loading and railcar loading areas . 

No organic dust: All tasks not considered to have exposure to raw 

or processed soybeans or soybean products, including loading oil 

into barges or railcars, working in the extraction building, 

working in the maintenance shop, and maintenance work in the 

general plant other than the areas classified above . 

V. EVALUATION CRITERIA 

A. Environmental Criteria 

As a guide to the evaluation of the hazards posed by workplace 

exposures, NIOSH field staff employ environmental evaluation 

criteria for assessment of a number of chemical and physical 

agents. These criteria are intended to suggest levels of exposure 

to which most workers may be exposed up to 10 hours per day, 40 

hours per week for a working lifetime without experiencing adverse 

health effects. It is, however, important to note that not all 

workers will be protected from adverse health effects if their 

exposures are maintained below these levels. A small percentage 

may experience adverse health effects because of individual 

susceptibility, a pre-·existing medical condition, and/or a 

hypersensitivity (allergy). 

In addition, some hazardous substances may act in combination with 

other workplace exposures, the general environment, or with 

medications or personal habits of the worker to produce health 

effects even if the occupational exposures are controlled at the 

level set by the evaluation criterion. These combined effects are 

often not considered in the evaluation criteria. Also, some 

substances are absorbed by direct contact with the skin and mucous/ membranes, and thus potentially increase the overall exposure. 

Finally, evaluation criteria may change over the years as new 

information on the toxic effects of an agent become available. 

The primary sources of environmental evaluation criteria for the 

workplace are: 1) NIOSH Criteria Documents and recommendations, 2) 

the American Conference of Govet'tlmental Industrial Hygienists' 

(ACGIH) Threshold Limit Values (TLVs), and 3) the U.S. Department 
Page 9 - Health Hazard Evaluation Report No HETA 84-477 

of Labor (OSHA) occupational health standards. Often, the NIOSH 

reconunended exposure limits (RELs) and ACGIH TLVs are lower than 

the corresponding OSHA standards. Both NIOSH RELs and ACGIH TLVs 

usually are based on more recent information than are the OSHA 

standards. The OSHA standards also may be required to take i.nto 

account the feasibility of controlling exposures in various 

industries where the agents are used; the NIOSH RELs, by contrast, 

are based primarily on concerns relating to the prevention of 

occupational disease. In evaluating the exposure levels and the 

recommendations for reducing these levels found in this report, it 

should be noted that industry is legally required to meet those 

levels specified by an OSHA standard. 

A time-weighted average (TWA) exposure refers to the average 

airborne concentration of a substance during a normal 8- to 10-hour 

workday. Some substances have recommended short-term exposure 

limits or ceiling values which are intended to suppleroent the TWA 

where there are recognized toxic effects from high short-teem 

exposures. 

B. Grain Dust Exposure Criteria 

Currently, neither NIOSH nor OSHA has an exposure criterion for 

grain dust. The OSHA permissible exposure limit (PEL) for nuisance 

dusts is 15 mg/m3 for total dust and 5 mg/m3 for the respirable 4 fraction. Epidemiologic studies of workers who handle grain 

have reported a variety of clinical syndromes related to 

environmental exposure. These have included allergic asthma, 

chronic bronchitis, febrile reactions (grain fever), fibrosis of 

the lung, rhinitis, and conjuctivitis. An increased prevalence of 

respiratory symptoms (such as sputum production, chronic cough, 

wheeze, chest tightness, breathlessness on exertion) has been 

demonstrated repeatedly in studies of grain elevator workers. 

Nasal symptoms, eye and skin i.rritation related to grain dust 

exposure are also common. Because of the accumulation of evidence 

regarding the harmful effects of grain dust, the American 

Conference of Governmental Industrial Hygienists (ACGIH) has 

recommended a TWA-TLV of 4 mg/m3 of total dust for grain 

workers.5 

In a study recentl! published by NIOSH, total dust exposures /

averaged 3.29 mg/m for 209 workers in the grain handling 6 industry. Medical findings from this study led the authors to 

conclude that exposure to grain dust during a work shift had a dose 

related acute adverse effect on the worker. The effects , which 

we.re largely on the respiratory system, were seen at total dust 

concentrations below 5 mg/m3. In addition. susceptible workers 
Page 10 - Health Hazard Evaluation Report No HETA 84-477 

(those wit~ pre --existing airways cbstruct~or.) experien~e<! 

significant declines in ventilatory function at dust levels below 

10 mg/m3. 

There have been no epidemiologic studies of soybean processing 

workers. Case reports have described occupational asthma in five 

soybean mill workers8 and asthma, rhinitis and conjunctivitis in 

a bricklayer's helper exposed. to soybean dust while working on the 

reconstruction of a soybean plant.9 PeterslO reported on a 

nut•se' s aide who developed soybean allergy manifested by asthma, 

rhinitis, and conjunctivitis after exposure to soybean- containing 

bath powders. Another case reportll described a previously 

not~-allergic woman who developed asthma after exposure to soybean 

flour at a company which manufactured dairy food products. She was 

a secretary whose symptoms resulted from minimal exposure . 

VI. RESULTS AND DISCUSSION 

A. Environmental 

Worker breathing-zone exposure results for total and respirable 

dust are presented in Tables 1 through 8. The highest exposures 

were experienced by workers in the Shipping and Receiving 

department. Within this department, those who perfot"med work at 

the harbor unloading bean barges had the highest exposures. This 

included workers who were assigned to the harbor and those who were 

transferred from other jobs during their work shift to help in 

barge unloading and cleanout. It takes about 14 hours to unload a 

bean barge. Most of the workers' time is spent outside the barge 

during this operation. The last 1.5 hours of this time are spent 

doing barge cleanout. Workers use a Bobcat (a small front end 

loader) and brooms to clean the bottom of the barge. This is a 

very dusty job. 

Single-use respirators were available to all workers. The use of 

respiratory protection was at the workers' discretion. In dustier 

jobs the use of respirators was widespread, although a number of 

the workers had beards which drastically compromises the 

respirator's efficiency. It is also questionable whether the 

single--use respirator provides adequate protection on a day to day 

basis in some of the higher exposure jobs. 

Raw soybean dust exposure results are presented in Tables 1 and 2. 

The range of total dust exposures was 0.16 to 22.6 mg/m3 for 34 

workers in this category (Table 1). The average for all samples 

was 3.73 mgtm3 . One of the utility workers performing cleanup in 

the head house was exposed near the OSHA PEL (14.7 mg/m3) and the 

other was overexposed (22.6 mg.m3). Seven total dust samples 

collected from workers inside the bean barge averaged 7.80 
Page 11 - Health Hazard Evaluation Report No HF.TA 84-477 

mgtm3 . Six of these seven worker s had dust exposures exceeding 

the ACGIH TWA-TLV of 4 mg/m3 and one exposure (14.2 mg/m3) 

approached the OSHA PEL . The 10 samples collected from workers 

dockside at the bean barge averaged 1.63 mg/m3. One of these, 

3.34 mg/m3, was near the ACGIH TWA-TLV . 

Respirable raw dust exposures from Table 2 ranged from 0.02 to 1.02 

mg/m3 and averaged 0.26 mg/m3 for 35 samples . Bean barge 

cleanup workers at the harbor and utility workers in the head house 

had the highest average respirable exposures , 0.45 and 0.42 

mg/m3, respectively. 

Exposures to the cleaner soybean dust are presented in Tables 3 and 

4. The tot al dust personal exposure results ranged from 0.18 to 

0.72 mg/m3 and averaged 0.48 mg/m3 for 13 samples (Table 3). 

The respirable dust results ranged from 0 . 01 to 0.15 mgtm3 with a 

mean of 0.08 mg/m3 (Table 4) . 

Exposures to extracted soybean dust are presented in Tables 5 and 

6. The 13 total dust sample results (Table 5) ranged from 0.18 to 

15.0 mg/m3 and averaged 2 . 28 mg/m3. One exposure to a worker 

loading railcars with soybean meal, equaled the OSHA PEL of 15 

mgtm3 . This worker loaded six railcars during the shift. Each 

railcar has three hoppers and it takes about 10 minutes to load 

each hopper. A load tube is placed over the top hatch, and when it 

i s nearly full the operator must manually move the load tube to 

distribute the last of the load evenly. This is the dustiest part 

of the job. Respirable dust exposures (Table 6) ranged from 0.02 

to 0.38 mg/m3 and averaged 0.11 mg/m3 . The highest respirable 

dust exposure was to the worker who was loading railcars. 

Six samples were collected from workers who were exposed to both 

processed and unprocessed soybean dusts (Tables 7 and 8). Four of 

t hese workers spent most of the work shift in the area to which 

t hey were assigned. Two of them split the shift evenly between the 

primary and secondary jobs. The mixed exposure in all cases here 

was to raw and extracted soybean dusts. The range of total dust 

exposures was from 0.76 to 16.2 mg/m3, and the mean was 5.77 

mg/m3 (Table 7). The higher exposures were to those who 

t ransferred from jobs· in the meal house to hel p set up or clean out 

bean barges. Three of these exposures exceeded the ACGI H TWA- TLV, 

and one of them exceeded the OSHA PEL. Respirable mixed dust 

exposures ranged from 0.06 to 0.47 mgtm3 and averaged 0 . 23 

mg/m3 (Table 8). 

'l'we.nty--two personal exposure samp l es were collected from a group of 

nine maintenance mecll.anics. Some of the results (five sample 

results) have been re.ported in the above tables when the exposure 
Page 12 - Health Hazard Evaluation Report No BETA 84- 4 77 

to a parti:c....ilar tyi;.e of dust waz lmown. Tae remaining 17 sample 

results ranged from 0.25 to 2.51 mg/m3, averaging 0.81 mg/m3, 

for total dust exposure and from 0.01 to 0.72 mg/m3, averaging 

0.22 mghn3, for respirable dust exposure. 

B. 	 Medical 

Response proportions, and participation in each examination: 

Participants in the February and March, 1985 examinations were 

drawn from the following departments: 

DEPARTMENT 	 11 ELIGIBLE ii in STUDY (3 of ELIGIBLE) 

Shipping & Receiving 26 25 (96) 

Process 19 15 (79) 

Maintenance 14 10 ( 71) 

TOTAL 59 50 (85) 

During the March visit, the questionnaire was administered to the 

two individuals who were on leave and therefore had not been 

interviewed in February. 

These individuals were excluded from the analyses pertaining to 

possible occupational asthma and possible occupational rhinitis, 

since the NIOSH physician who had made those clinical assessments 

in February was not present in March to review these two 

questionnaires. 

The number of employees completing each portion of the medical 

screening is tabulated as follows: 

Questionnaire so (48 for asthma and rhinitis 

analyses) 

Peak flow recordings 32 (with adequate data for 

analysis) 

Skin tests 49 

I·num.mologic tests (RAST 49 

and 	serum total IgE) 

I 

Spirometry testing was performed on the following number of workers 

for each category of tests: 

(l) 	Pre-· and post- shift spiromett·y on the first day back at work: 

46 workers. 

(2) 	End-of- week spirometry: 42 workers. 
Page 13 - Health Hazard Evaluation Report No HETA 84-477 

Description of the study participants 

Of the 50 participants, 44 were white and 6 were black. A.11 

participants were male. Their ages ranged from 24 to 54 years, 

with a mean of 34.1 years. Length of employment at the plant 

ranged from 4 to 10 years, with a mean of 8 years. 

One participant had an extremely elevated serum total IgE level and 

a positive skin test for Aspergillis, as well as 20 other positive 

skin tests. He had 9 positive RASTs. It could not be ruled-·out, 

without further investigation, that the elevated serum IgE level 

was due to chronic allergic bronchopulmonary aspergil.losis, a 

disease that may or may not be work- related in any given 

.individual. (This was explained to the participant i.n writing, and 

he was urged to consult a local physician for further 

investigation. ) Extremely elevated serum IgE levels can result in 

non-specific binding in the RAST assays and yield positive results 

that are not due to specific allergy to the substances tested. 

This participant's data was not removed from the analyses that 

follow. Were the data to have been eliminated from further 

consideration, the results would not have been changed. 

Possible Asthma 

On the basis of their questionnaire responses, 22 of 48 employees 


were identified as having met the predetermined criteria for 


possible asthma. Of these, 15 met the criteria for occupational 


asthma, and 7 were designated non-occupational asthma (Table 10). 


To validate the tentative diagnosis of asthma, evidence of 

reversible airways obstruction was sought in the peak expiratory 

flow rate data. Thirty-two of the participants submitted adequate 

PEFR data for analysis. This includes the two employees who 

answered the questionnaire in March, so only 30 sets of PEFR data 

are included in analyses concerning possible asthma or rhinitis. 

F'ive of these 30 had evidence of reversible airways obstruction on 

at least one day: three of 13 possible asthmatics and 2 of 17 

non-astlunatics. Among the 14 participants with possible 

occupational astluna who did the spirometric tests, the mean 

difference between pre- and post-shift FEV1 (as a percent of 

predicted) was +0.79 percent, compared to a mean difference of -2 . 0 

percent among the 24 non-asthmatics (Table 11). In this analy~is , 

pre-shift percent FEV1 was subtracted from post-shift percent 

FEV1 , so that a positive difference means an increase in 

one-second forced expiratory volume over the course of a 

work-shift. Changes in FEV1 over the course of a workshift , for 

possible occupational asthmatics and for normals, were in 

directions opposite to what would be hypothesized, if indeed those 

persons suspected to have possible asthma, actually had asthma. 
Page 14 - Health Hazard Evaluation Report No HETA 84- 477 

Thus, we w~re unable to demonst::-atG through ;:my objective data that 

our designation of aslhma was medically valid. In the rest of this 

report, the symptoms that were tentatively diagnosed as asthma by 

the questionnaire criteria, will be referred to as lower 

respiratory symptoms (l.RSx), for which the underlying 

pathophysiology is undetermined. 

In the questionnaire interview, employees were asked to identify 

three specific jobs at work that caused their respiratory 

symptoms. Fourteen (933) of the 15 people identified as having 

work--related lower respiratory symptoms (LRSx) identified jobs 

involving exposure to raw dust as the jobs during which their 

symptoms were "most likely to occur." (Table 12.) Overall, of the 

45 possible responses, 27 (603) were for jobs which entailed raw 

dust exposure. 

Of the 15 lower respiratory symptoms (LRSx) cases, 9 were currently 

working in the shipping and receiving department, three were in 

processing, and three were maintenance workers. The three 

processing workers were all utility workers who associated the 

occu1.·rence of their respiratory symptoms primarily with clean-up 

tasks. One processing utility worker said specifically that his 

·cespiratory symptoms occurred while "shoveling beans with high 

dust." Similarly, the three maintenance employees specifically 

reported raw dust exposure jobs as the primary tasks causing their 

respiratory symptoms. 

Possible rhinitis 

On the basis of their questionnaire responses, 17 of 48 employees 

were identified as having possible rhinitis. Of these, 12 met the 

criteria for being occupational rhinitis, and 5 were designated as 

non-occupational rhinitis. (Table 10.) There were no specific 

tests to validate the designation of possible rhinitis by the 

questionnaire criteria. 

In the questionnaire interview, employees were asked to identify 

three specific jobs at work that caused their rhinitis symptoms. 

Ten (83~) of the 12 people identified as having possible 

occupational rhinitis identified jobs involving exposure to raw 

dust as the jobs during which their symptoms were "most likely to 

occur." (Table 13.) Overall, of the 36 possible responses, 25 (69~) were for jobs which entailed raw dust exposure. 
Page 15 - Health Hazard Evaluation Report No HETA 84- 477 

Lower respiratory symptoms, and skin prick tests: 

Thirty- one skin tests were applied to each of 49 participants, to 

detect immediate, IgE mediated allergy to 11 soybean fractions and 

products, 3 insects, 6 molds, 7 grains and grasses, and 2 other 

allergens. Those skin tests for which five or more study 

participants had positive reactions, were examined to determine if 

t here was a relationship between work-related lower respiratory 

symptoms and allergy, as evidenced by positive skin prick tests. 

Percent of positive skin test responses 

Work-related lower respiratory tract SYffiPtoms? 

Skin test substrate Yes No 

Aspiration baghouse dust 28.6 37. 0 

Truck dump dust 28.6 29.6 

Head house dust, D-27 28.6 29.6 

Hulls 21.4 14.8 

Barge dust 7.1 18.5 

Any soybean reaction 26.7 37.0 

Mixed insects 28.6 22 . 2 

Dust mites 28.6 25.9 

Grain mites 14.3 11.1 

Any insect reaction 33.3 33.3 

For each skin prick test, the proportion of positive responses 

among participants with work- related lower respiratot·y tract 

symptoms, was less than or indistinguishably greater than the 

proportion among participants with no such symptoms. Further.more, 

except for the one individual with significantly elevated serum 

total IgE levels, there were no positive RASTs for any soybean 

f raction or dust sample. Therefore, the data collected did not 

demonstrate that the work-related lower respiratory tract symptoms 

occurred on an allergic basis . 

Rhinitis, and skin prick tests 

The same analysis was repeated , to examine the relationship betwe~n 

work- related rhinitis, and allergy. 
Page 16 - Health Hazard Evaluation Report No HETA 84- 477 

Percent of positive skin test responses 

Work-related rhinitis? 

Skin test substrate Yes No 

Aspiration baghouse dust 16 . 7 40.6 

Truck dump dust 16. 7 34.4 

Head house dust, D-27 16.7 34.4 

Hulls 8.0 21.9 

Barge dust 16.7 15.6 

Any soybean reaction 16.7 40.6 

Mixed insects 16.7 28.l 

Dust mites 8.3 31.3 

Grain mites 0.0 15.6 

Any insect reaction 25.0 37.5 

Again, for each skin prick test, the proportion of positive 

responses among participants with work-related rhinitis was no 

greater than the proportion among non-cases . Furthermore, in 

addition to the one individual with significantly elevated serum 

total IgE levels, only one individual had a positive RAST for 

insect parts. Therefore, the data collected did not demonstrate 

that the work-related rhinitis symptoms were caused by allergic 

·mechanisms. 

We examined the acute effect of dust exposure on pulmonary function 

by comparinr, pre- and post-shift pulmonary function values among 

employees, categorized by dust exposure (raw, cleaner, extracted) 

according to the task they were performing during the day of 

interest. Only employees who spent the entire shift in one dust 

exposure category were so categorized. An individual who had spent 

half of his shift unloading a barge ("raw" dust exposure), and then 

half the shift loading meal trucks ("extracted" dust exposure) was 

not considered in the analysis of cross-shift FEV changes, since 1 

he would have had a "mixed" exposure. An employee who had worked 

primarily as a prep operator ("cleaner" dust exposure), but spent I 

one hour relieving the extraction operator ("no organic dust" 

exposure), was characterized as having "cleaner" dust exposure, 

since he was exposed to only one "type" of dust. 

The pulmonary function change of primary interest in the analysis 


of acute effects is the cross-shift difference (or change) in the 


one-second forced expiratory volume (FEV1), commonly examined as 


the percent of predicted FEV1. For the total of 46 workers who 


participated in the cross-shift spit·ometery testing done on the 

Page 17 - Health Hazard Evaluation Report No HF.TA 84-477 

first day back at work (after two days off), the mean FEV1 

percent predicted declined from 94.39 to 93.30, a mean cross-shift 

difference of 1.09 (Table 14). This decrease was statistically 

significant (p=.03). 

In an attempt to examine the effects of the various dust categories 

(raw, cleaner, extracted), we looked at the workers who had 

performed tasks which exposed them to only one type of dust during 

their first day back at work. The 15 workers exposed only to raw 

soybean dust had a very small cross-shift. increase (0.40) in the 

mean percent predicted FEV1 . The mean percent predicted FEV1 

declined cross-shift. 1.67 for the 12 workers exposed only to 

cleaner dust, and 2.75 for the 4 workers exposed only to extracted 

dust. The mean respirable dust level was greater for the workers 

exposed to "raw" dust (0.25 mg/m3) than for the workers exposed 

to "cleaner" or "extracted" dust (both 0.07 mg/m3). This 

finding, namely, improved percent predicted· FEV1 among workers 

with higher respirable dust exposures, exposed primarily to "raw" 

dust, is contrary to what we would expect to observe, were the 

underlying pathophysiology of the symptoms experienced by workers 

due to asthma from occupational dust exposures. However, when the 

study participants are broken down into the three separate dust 

exposure types , the numbers become very small, and the mean 

differences in FEV1 percent predicted values are therefore 

unstable estimates, easily influenced by one or two extreme values 

in any group. For example, when the extracted and cleaner dust 

categories were combine.d, there were changes in both the magnitude 

and the direction of the mean differences for FVC, FEV1 , and the 

FEV1/FVC ratio. In addition, workers who wore respirators 

(especially cartridge respirators) would not presumably truly have 

been exposed to the measured dust level. All five participants who 

wore respiratory protection during the first day back at work were 

in the raw exposure category (4 workers wore single-use disposable 

respirators and one worker wore a cartridge respirator). When 

those 5 workers were not considered in the analysis, the mean 

inci-ease in precent predicted FEV1 for the "raw" exposut:·e group 

was only 0.13. Therefore, it is difficult to ascribe with 

confidence any meaningful physiological interpretation to the 

results for the specific dust categories. 

For analyses of chronic effects, we determined the cumulative 

amount of time that an employee had spent in each exposure sett~ng 

(raw, cleaner, extracted, no organic dust). Most P.mployees at 

Bunge had not changed departments frequently, but employees within 

one department may do a variety of tasks that expose them to raw or 

processed soybeans. Therefore, very detailed job histories were 

taken from employees. For example, for jobs in the shipping and 

receiving department, employees were asked what percentage of that 

time they spent doing unloading, loading or "other" operations. 
Page 18 - Health Hazard Evaluation Report No HETA 84-477 

ii'or loadinr, operation3, they were asked what peL"centage of t!lat 

time they spent loading meal, hulls, or oil. For "other" 

ope.cations, they were asked to list every task they remembered 

performing (cleaning out the storage tanks, working in the head 

house, etc.) and the percentage of time they spent doing those 

tasks. Prep operators and utility people were asked to give 

similarly detailed histories. This information was used to 

calculate, for every job, the percentage of time spent i.n each 

exposure category. 

From interviews with the maintenance employees and supervisors, a 

typical distribution of possible tasks was determined, and all time 

spent in maintenance jobs was assigned the following percentages 

for the various dust exposure categories: 53 raw; 53 cleaner; 3'7a 

extracted; 873 no organic dust exposure. 

First day ·back- to--work, pre-shift, percent of predicted FVC (FVC%) 


and FEV (FEV 3), and FEV1/FVC ratio , were examined in linear 
 1 1

regression models, as functions of: 


(1) pack years of smoking, years in shipping and receiving 

(department 1) , years in process (department 2), and years in 

maintenance (department 3); 

(2) pack years of smoking, years of exposure to " raw" dust, 

years of exposure to "extracted" dust, and years of exposure to 

"cleaner" dust; 

(3) pack years of smoking, years of exposure to "raw" dust, 

and years of exposure to "extracted" and to "cleaner" dust 

c<>mhined . 

Age and race were not included in the regression models, since the 

FVC and FEV variables were expressed as percents of predicted 1 

for age, sex, and race . 

In the first set of regression analyses, FVC1o and FEV 3 both 1

increased with years in maintenance, and were not correlated with 

any other variable when years in maintenance was in the regression 

model. FEV 1FVC ratio was not significantly explained by any of 1

the exposure variables . We hypoth esized that the paradoxical 

improvement in pulmonary function , as evidenced by increasing FVC"To 

/ and FEV13 with years in maintenance, really reflected the 

converse, that is a decrease in pulmonary function associated with 

total duration in shipping and receiving, and process, combined. 

In the second set of regression analyses , FEV 3 was borderline 
 1

negatively correlated with pack years of smoking, while FVC1o and 


FEV /FVC were not correlated with any.of the independent 
 1

variables. The same results were noted for the third set of 


regression analyses. 

Page 19 - Health Hazard Evaluation Report No HETA 84-477 

To follow-up on the hypothesis that the paradoxical "protective" 

effect of years in maintenance on FVC3 and FEV ~ was merely the 

inverse of years in shipping and receiving, and process, we 

regressed FVC'I., FEV ~. and FEV /FVC on 1

(1) pack years of smoking , and total dust exposure; and 

(2) pack years of smoking, and years in either shipping and 

receiving or in process, combined. 

We found, in regard to the first set of regression analyses that 

FEV'1.. was negatively related to pack years of smoking at a 

borderline significance level (Table 19). In regard to the second 

set of regression analyses (Tables 20 and 21), as we hypothesized , 

FVC'I. and FEV ~ were negatively related to years in 

shipping/receiving and process, although at borderline significance 

levels. The observed effects may be roughly interpreted as a 1 

percent loss in FVC and FEV , in excess of that predicted for 1

age , sex , and race, for each year of work in shipping/receiving or 

in process, combined. When years of work in the$e departments were 

entered in the analysis, pack years of smoking did not 

significantly explain any additional amount of variation in lung 

function. 

CASE DESCRIPTIONS 

Twel ve people reported having been awakened from sleep by 

respiratory symptoms consistent with nocturnal asthma, that is, 

delayed onset asthmatic ·reactions. Case descriptions for the eight 

who reported this occuring more than twice are given below. Five 

of these men had work-related lower respiratory symptoms. Two had 

lower respiratory symptoms exacerbated by work. Another reported 

tttat his acute respiratory symptoms were only work-related, but he 

did not meet the criteria for lower respiratory symptoms. 

1. 	 This non-smoking shipping and receiving worker reported that he 

always experienced wheP..zing and shortness of breath after 

working in a bean barge, if he di d not wear a dust mask. He 

had experienced at least five episodes of being awakened from 

sleep by these symptoms, after working in a barge. By the 

questionnaire criteria, he was classified as having 

work- related lower respiratory symptoms. He also reported in 

his medical interview that his eyes became "red and watery" 

when he worked with raw beans, although he did not meet the 

criteria for rhinit.is. On lhe last day of the survey, when he 

came for his post-·shift PFTs, the medical officer observed him 
Page 20 - Health Hazard Evaluation Report No HETA 84--4 7 7 

~o have ?:iilateral conjur.~tival inflammation (rec eyes), with 

redness and swelling around his eyes. She also noted that he 

had audible wheezing, and was coughing frequently, although he 

did not spontaneously complain of respiratory symptoms. He 

reported that he had been driving the bobcat during clean- out 

of a 

barge. Although his pulmonary function tests ·were within 

normal limits for epidemiological purposes, his FEV1 was 8S'fo 

of predicted. His peak expiratory flow data did not 

demonstrate respiratory tract labi.lily characteristic of asthma. 

2. 	 This shipping and receiving worker was noted by the medical 

officer to have bil ateral conjunctival inflammation and 

periorbital redness and swelling when he came for post- shift 

pulmonary function tests after working in a barge. He reported 

that his eyes fe l t burni ng and scratchy. He met questionnaire 

criteria for work- related lower respiratory symptoms and 

work-related rhinitis. He was a cigarette- smoker with normal 

pulmonary func.tion tests. He did not return his peak flow 

records for evaluation. 

3. 	 This shipping and receiving worker reported shortness of 

breath, chest tightness, and cough, and reported that he had 

been awakened from sleep with these symptoms approximately 

twice a month for the last five years .. He associated these 

symptoms with working in barges, especially with new soybeans 

in autumn. He met questionnaire criteria for work-related 

lower respiratory symptoms and work-related rhinitis. He was a 

cigarette- smoker with normal pulmonary function tests. He did 

not return his peak f low records for evaluation. 

4 . 	 This maintenance worker reported chest tightness and cough 


whenever he was around " irritating unprocessed bean dust," 


noting the Head House especially. He reported having been 


awakened from sleep by these symptoms at least twice a year 


since he started working at Bunge. He was a non-smoker, who 


met the criteria for work- related lower respiratory symptoms. 


He did not do the pulmonary function tests or peak flow 


measurements. 


5. 	 This shipping and receiving worker reported wheezing, shortness 

of breath and chest tightness, that had awakened him from sleep f 

approximately three times a month for the last three years. He 

reported that raw soybeans were the only thing that caused his 

problems. He had abnormal FEV and FVC values (less than 1 80~ 

predicted) and nonnal peak flow measurements. He was a former 

cigarette smoker , who met the criteria for work- related lower 

respiratory symptoms . 
Page 21 - Health Hazard Evaluation ~eport No HETA 84-477 

6. and 7. Two men with histori es of childhood asthma reported both 

work- related and non-work- related factors causing their acut e 

respiratory symptoms, which awakened them from sleep 

intermittently. They were classified as non- work- related lower 

respiratory symptoms. They had normal pulmonary function 

tests. 

8. 	 This maintenance worker reported shortness of breath and cough, 

that had awakened him from sleep approximately four times a 

year since starting to work at Bunge. He associated these 

symptoms with grinding flaking rolls and working on the drags 

in the Head House. He did not meet the criteria for. asthma , 

but was classified as having work-related rhinitis. He was a 

cigarette smoker, with normal pulmonary function tests and peak 

flow records. 

FAMU.IAL REPORTS 

During the questionnaire interview, each employee was asked "Does 

anyone living in tbe same house with you have health problems you 

think may be related to dust you bdng home from work?" Thirteen 

of the fifty participants (263) described a family member's health 

complaints, that they thought were related to soybean dust carried 

home on work clothes and/or boots. Workers reported wives and/or 

children having experienced the following symptoms (with the 

frequency in parentheses): asthma (1), eye irritation (2), nasal 

symptoms such as sneezing or runny nose (5), sinus problem (1), 

skin rash (5). The largest number of employees reporting familial 

symptoms were from shipping and receiving (8 workers); four were 

from maintenance and one was from processing. 

VII. CONCLUSIONS 

The 	industrial hygiene monitot"ing results show that exposures to 

soybean dusts above the OSHA PEL and the ACGIH TWA-TLV are possible in 

a number of jobs, particularly working inside bean barges, loadi..ng 

railcars with meal, and utility cleanup jobs. Other jobs with 

potential for high exposure are unloading railcars and trucks in the 

receiving area of the head house, and loading meal trucks in the meal 

house. The medical survey result s demonstrated a high prevalence of 

work-related acute lower respiratory symptoms, and for: the group as a 

whole, there was a small but significant (1.093) cross-shift decJine Jn 

FEV1 during the first day back at work. The peak flow meter: and 

spirometry data did not support the designation of asthma by 

questionnaire cL·iteria. However, i t is well-known that cross-shift 

spirometL·ic pulmonary function tests may fail to idP.ntify occupational 

asthma cases, depending on the time of onset of the asthmatic 

reaction. As noted in a· recent review of oc.cupational asthma by Moira 

Chan- Yeung, M.o .12, 
Page 22 - Health Hazard Evaluation Report No HETA 84- 477 

·Measure:~ettt of change ia spiro'!ketL·y over 1 wor~ shift, if 

positive , is good evidence of work- relatedness. It is not a test 

on which to exclude work-related asthma." 

Similarly, there are limitations to the interpretability of the peak 

expiratory flow rate (PEFR) measut'ements performed during this study. 

P. Sherwood Burge, M. D. , a leading proponent of the use of individual 

portable peak flow meter testing, seriously cautions over- interpreting 

negative results f r om PEFR testing performed over the short time period 

used in this study13. Dr. Burge recommends that the peak expiratory 

flow rate record should be kept for at least a week at work followed by 

two weeks away from work , followed by another t wo weeks at work. This 

prolonged record may be necessary in order to al.low enough time away 

from possible work-related asthma-causing agents for an individual to 

regain maximal respiratory function, and then be able to see a pattern 

of decline in function when the person returns to work. Clearly, it 

was not possible to arrange for employees to be away from work for two 

weeks, for a study such as this. As with the cross-shift PFT results, 

the lack of strong l y positive results in the one week of PEFR testing 

(that was done in this study as a screening approach), cannot be 

interpreted as excl uding the possibiliby of work-rel ated asthma 

associated with soybean dust exposure. 

There was clearly a high prevalence of acute respiratory and rhinitis 

symptoms among Bunge employees, and the overwhelming majority of the 

jobs reported "most likely" to cause these symptoms involved exposure 

to raw soybean dust. Since raw dust exposure jobs at Bunge tend to be 

higher dust exposure jobs, one can only hypothesize regarding the 

relative importance of the quantitative level of dust versus 

qualitative characteristics of raw soybean dust . In studies of grain 

workers, NIOSH researchers6 and others14 have observed dose- related 

acute adverse effects, mostly respiratory, among workers whose total 

dust exposures were below 5 mg/m3. 

From the nrultiple regression statistical models, there is a suggestion 

of an association between years of employment in shipping/recP.iving and 

processing and a chronic effect on depression of FEV1 and FVC. 

BerrylS estimates that for a cross-sectional study such as this with 

a mean exposure time of 8 years, it would require 68 subjects in the 

study group and a control group to detect a difference of 0.03 liter 

per year in FEV1 (with a significance level of 0.05 and power 0.8). 

The fact that borderline significant declines in FEV1 and FVC were 

found in a study group as small as this one suggests that there is a 

true adverse chronic pulmonary effect from soybean dust exposure. It 

has been shown in studies of coffee workers16 and tea workers17 

that exposure to organic dust at relatively low respirable levels 

similar to this study can result in impaired pulmonary function and 

increased prevalence of chronic respiratory symptoms. 

I 
Page 23 - Health Hazard Evaluation Report No HETA 84-477 

As n')tcd in the "Enuironment.al Criteria" se~tion, it is cet'tainly 

biologically plausible that soybeans or contaminants in the raw soybean 

dust could cause respiratory and rhinitis symptoms. It is not yet 

clearly understood whether organic vegetable dusts induce t'espiratory 

and mucosa! reactions by chemical, mechanical, or allergic mechanisms. 

Since the skin testing in this study demonstrated that this group of 

workers is not atopic, evidence of acute or chronic responses to 

occupational exposures at Bunge cannot be attributed to predisposi.ng 

allergic tendencies among the employees. Also, there was no 

distinguishable pattern of skin test or RAST reactivity in symptomatic 

compared to asymptomatic workers. Therefore, possible occupational 

lower respiratory symptoms and rhi.nitis were not demonstrated in this 

study to have occurred on the basis of allergic mechanisms. 

It is also unclear which component(s) of the dust from commodities such 

as soybeans and grain may be responsible for adverse health effects. 

It is reasonable to anticipate that soybean dust, like other grain 

dust, will be shown to be a complex misture, consisting of pat'ticles of 

various other types of grain, fungal spores, insect parts, pollens, 

animal hair, and numerous agricultural chP-micals at various stages of 

degradation. These consistuent contaminants all have their own 

irritant and/or allergic potential. 

Until the role of soybean dust exposure in contributing to chronic or 

acute respiratory disease is further clarified, it would be prudent to 

minimize employees' exposure to soybean dust ; The use of ventilation 

in enclosed areas, such as the rail and truck receiving areas and the 

t~1ck and rail loadout areas, should be studied. It may be possible to 

use localized ventilation at the receiving stations where the soybeans 

are dumped. Ventilated enclosed control rooms are feasible for the 

meal loadout areas. The rail loadout would require automation of the 

loading chute, so that it would not have to be moved manually. The 

tt"Uck loadout is already controlled from a room which is not 

ventilated. The current practice at Bunge is to remove (partially) two 

covers from barges prior to unloading the soybeans. Instead, four 

covers should be removed completely, in order to decrease the amount of 

dust trapped inside the barges. 

While engineering controls are being instituted, personal respiratory 

protection should be worn by employees in all raw dust exposure jobs. / 

In addition, respirators should be worn when perfot:"ll\ing high dust 

exposure jobs in the prep building, such as clean-up on the first floor 

and clean-up or maintenance of the cracking rolls. 
Page 24 - Health H~zard Evaluation Report No HETA 84- 477 

VIII. RECOMMENDATIONS 

1. 	 Engineering controls should be installed in the soybean receiving 

areas and the soybean meal shipping areas. Local exhaust 

ventilation would be effective at the soybean dumping stations in 

receiving. Enclosing the truck and railcar loadout operators in 

ventilated, glass enclosures is feasible in the meal house. 

Instead of removing two barge covers partially, four covers should 

be removed completely prior to unloading. These and other methods 

to control dust should be investigated. 

2. 	 A respiratory protection program should be established in 

accordance with the OSHA General Industry Standard, section 

1910.134. Workers should be provided respirators equipped with 

dust cartridges in place of the single-use disposable respirators 

currently used. Powered air-purifying respirators may be an 

altecnative which should be considered. These tend to be more 

comfortable and also provide eye and face protection. Workers in 

jobs which require respiratory protection should not have beards. 

IX. 	REFERENCES 

1. 	 National Institute for Occupational Safety and Health. NIOSH manual 

of analytical methods. 3rd ed. Cincinnati, Ohio: National 

Institute for Occupational Safety and Health, 1984. (DHHS (NIOSH) 

publication no. 84-100). 

2. 	 American Thoracic Society. Snowbird workship on standardization of 

spirometry. Am. Rev. Resp. Dis. 1979;19:833-838. 

3. 	 Knudson RJ et al. Maximal expiratory flow-volume curve. Am. Rev. 

Resp. Dis. 1976;113:587-600. 

4. 	 Occupational Safety and Health Administration. OSHA safety and 

health standards. 29 CFR 1910.1000. Occupational Safety and Health 

A.dministr:ation, re1vised 1983. 

5. 	 American Conference of Governmental Industrial Hygienists. 

Threshold limit values for chemical substances and physical agents 

in the workroom environment and biological exposure indices with 

inte.nded changes for 1986-87. Cincinnati, Ohio: ACGIH, 1986. 

6. 	 NIOSH technical report. Study of the prevalence of chronic, 

non-specific lung disease and related health problems in the grain 

handling industr.-y. Cinti, Ohio. National Institute for 

Occupational Safety and Health, October 1986. (DHHS (NIOSH 

public.ation no. 84- 100). 
Page 25 - Health Hazard Evaluation Report No HETA 84- 477 

7. 	 Thedell , TD. Respirable and Total Dust Exposures of Workers in Six 

Exporting Grain F.levators, January 1980 .. 

8. 	 Duke WW. Soybean as a possible important source of allergy. J. of 

Allergy 1934; 5:300-302. 

9 . 	 Olsen AH & Prickman LE. Hypersensitivity to soy beans. Proc. of the 

Staff Meetings of the Mayo Clinic 1936; 11:465-469. 

10. 	 Peters GA. Bronchial asthma due to soybean allergy. Annals of 

Allergy 1965; 23:270-272. 

11. 	 Bush· RK & Cohen M. Inunediate and late onset asthma from occupational 

exposure to soybean dust. Clin. Allergy 1977; 7:369- 373. 

12. 	 Chan-Yeung M & Lam S. Occupational asthma . Am. Rev . Resp. Dis. 1986; 

133:686-703. 

13. 	 Burge PS. Could you be overlooking occupational asthma? J. Resp. 

Dis. 1982; 3(4):97-112. 

14. 	 DoPico GA et al. Acute effects of grain dust exposure during a work 

shift. Am. Rev. Resp . Dis. 1983; 128:399-404. 

15. 	 Berry G. Longi_tudinal observations. Their usefulness and 

limitations with special references to the forced expiratory 

volume. Bull. Physio-path. Resp . 1974; 10:643-655 

16. 	 Zuskin E et al. Ventilatory capacity and immunological reaction in 

coffee workers. Arh. Hig. Rada Toksikol. 1979; 30(suppl.):933-938. 

17. 	 Castellan RH et al. Pulmonary function and symptoms in herbal tea 

workers. Chest 1981; 79(suppl):81S-85S. 

1 

IX. 	 AUTHORSHIP AND ACKNOWLEDGF.MENTS 

Report Prepared by: 	 Sara Arnold, M.D. 


Medical Officer 


Medical Section 


Michael s. Crandall, CIH 

Industrial Hygiene F.ngineer 

Industrial Hygiene Section 

Alexander Blair Smith, M.D., M.S. 

Chief, Medical Section 
Page 26 - Health Hazard Evaluation Report No HETA 84 - 477 

Field Investigation: Sara Arnold, M.O . 

Medical Officer 

Medical Section 

Diane Bennett, M.O. 

Medical Officer 

Medical Section 

Michael s. Crandall, CIH 

Industrial Hygiene Engineer 

Industrial Hygiene Section 

Richard w. Har tle, CIH 

Industrial Hygienist 

Industrial Hygiene Section 

Kenneth K. Wallingford , CIH 

Industrial Hygienist 

Industrial Hygiene Section 

Jim Boyd 

Electronics Engineer 

Support Services Branch 

Marian Coleman 

Health Techni cian 

Support Services Branch 

Martin R. Berkeley 


Health Survey Spe~ialist 

Support Services Branch 

Statistical Su pport:· Shiu T. Lee 

Statist.ician 

Support Services Branch 

Laboratory Assistance: D. I. Bernstein, M. D. 

John S. Gallabher, Ph.D. 

University of Cincinnati 

College of Medicine 


Division of Immunology 

TABLE 1 

Total 

Raw Soybean Oust 

Dust Personal Exposure Results 

Bunge Corporation 

Decatur, Alabama 

March 3-6, 1985 

HETA 84-477 

Area Job 

Avg Sample 

n Vol~rne (m ) 

Concentration, mg/rn3

Range Mean 

Head House Control Room 

Dryer 

Receiving 

Utility (cleanup) 

4 

5 

2 

2 

1.02 

1.42 

1.03 

1.04 

o. 37-0.89 

0.16-3.22 

1.39-2.32 

14.7-22.6 

0.56 

1.61 

1.86 

18 . 6 

arbor H Bean Barge 

-Dockside 

-In Barge 

-A 11 

10 

7 

17 

1.06 

1.06 

1.06 

0.60-3.70 

1.03-14.2 

0.60-14.2 

1.63 

7.80 

4.17 

Maintenance Prep/1st Fl()or 2 1.10 0.67-3.34 2.00 

Process/Prep Utility (cleanup) 2 1.05 0.41 -0.46 0.44 

All Samples 34 0.16-22.6 3. 73 

-----------------------------------------------------------------------------

( 
-

TABLE 2 


Respi r abl e 

Raw Soybean Oust 


Oust Personal Exposure Results 


Bunge Corporati on 


Decatur, Alabama 


March 3-6 , 1985 


HETA 84- 477 

------------------------------------------------------------------------------

Area 

--------------

Job 

--------------

Avg Sample 

n Volume Co nce ntra ti on , mg/m3 

(m3) Range Mean 

--------------------------------------------------

ead House Contro1 Room 

Dryer 

Recei vi ng 

Util ity(cleanup) 

4 

5 

2 

2 

0.86 

1.23 

0.88 

0.89 

0.03-0 .26 

0.03-0 . 23 

0. 10-0.25 

0. 20 0.64 

0.1 3 

0. 13 

0.18 

0.42 

arbor Bean Ba r ge -Oocksi de -In Barge 

-All 

10 

8 

18 

0.90 

0.78 

0.85 

0. 02 -0.64 

0.17- 1. 02 

o. 02-1. 02 

0.20 

0.45 

0. 31 

t·la i ntenance Prep/1st Floor 2 0.94 0.02-0.67 0. 34 

Process/Prep Utility (cleanup) 2 0.90 0.09-0 . 20 0.14 

All Samples 35 o. 02-1. 02 0.26 

---------- -------- -~-- -- -- -- -- -- -- ----- ---- -- -- -- -- ----- --- ----- ----

-

H

­

H

I 
-------------------------------------------------------------------------------

TABLE 3 

Cleaner Soybean Dust 


Total Oust Personal Exposure Results 


8unge Corporation 


Decatur, Alabama 


March ~-6, 1985 


HETA 84-477 

Avg Sample 

Area Job n Volume Concentration, mg/m3 (m3) Range Mean 

-------~--------------------------------- ----------- ---------------------------

Process/Prep 	 Opera tor 3 1.41 0.18-0.47 0.32 

Utility 5 1.18 0.24-0.66 0.48 

Rover 2 1.48 0.32-0.60 0.46 

Maintenance 	 Prep/2nd Floor 3 1.09 0.52-0.72 0.64 

All Samples 	 13 0.18-0.72 0.48 

TABLE 4 

Cleaner Soybean Oust 


Respirable Dust Personal Exposure Results 


Bunge Corporation 


Decatur, Alabama 


March 3-6, 1~85 

HETA 84-477 

Avg Sample 

Area Job n Volume Concentration, rng/m3 / ( m3) Range Mean 

Process 	 Opera tor 3 1.23 0. 02-0.15 0.09 


utility 5 1.04 0.01-0.15 0. 08 


Rover 2 1. 25 0.04-0.08 0.06 


Maintenance 	 Prep/2nd Floor 3 0 . 93 0.07-0.09 0. 08 

A11 Sa mp 1es 	 13 0. 01-0.15 0.08 

\ 

I 


l 


I 

TABLE 5 


Extracted Soybean Dust 


Total Dust Personal Exposure Results 


Bunge Corporation 


Area 

Meal House 

A11 Samples 

Area 

Meal House 

All Samp1es 

Decatur. Alabama 


March 3-6, 1985 


HETA 84-477 

Avg Sample 

Job n Volume Concentration, mg/m3 

(m3) Range Mean 

Contro1 Room 5 1.06 0.55-0.94 o. 71 

Load Ra i 1car 7 1.06 0.18- 15. 0 3.55 

Load Truck 1 1.02 1.25 

13 - 0.18-15 . 0 2.28 

TABLE 6 

Extracted Soybean Oust 


Respirab1e Dust Personal Exposure Results 


Bunge Corporation 


Decatur, Alabama 


March 3-6, 1985 


HETA 84-477 

Avg Sample 

Job n Vol~me Concentration, mg/m3 (m } Range Mean 

Con tro1 Room 5 0.91 0.02-0.21 0.11 

Load Railcar 7 0.89 0.02-0.38 0.11 

Load Truck 1 0.90 0.08 

13 0.02-0.38 0.11 
-· 

TABLE 7 

Mixed Soybean Dust 


Total Dust Personal Exposure Results 


Bunge Corporation 


Oecatur, Alabama 


March 3-6, 1985 


HETA 84-477 


Assigned 


Area 


Sample 

Job Hours Volume 

Primary/Secondary Pri/Sec (m3) 

Con cen tra ti on 

(mg/m3) 

Harbor Bean Barge/Meal House 6/2 1.03 0. 76 

Meal House Control Room/Bean Barge 7/1 1.09 

Load Truck/Bean Barge 4/4 1.09 

Load Rail Car/Bean Barge 7/1 0.96 

Load Rail Car/Bean Barge 4/4 1.05 

Load Rail Car/Bean Barge 7/1 1.06 

4.16 

16.2 

2. 67 

4.41 

1.39 

A11 Samples 5. 77 

I 
TABLE 8 


Mixed Soybean Dust 


Respirable Dust Personal Exposure Results 


Bunge Corporation 


Decatur, Alabama 


March 3-6, 1985 


HETA 84-477 


Assigned 

Area 

Sample
 job Hours Volume 

Primary/Secondary Pri/Sec (m3) 

Concen tra ti on 


(mg/m3) 


Harbor 	 Bean Barge/Meal House 6/2 0. 88 0.06 

Meal House 	 Control 

Load Truck

Load Rail 

Load Rail 

Load Rail 

Load Rail 

koom/Bean Harge 

/Bean Barge 

Car/Bean Barge 

Car/Bean Barge 

Car/Bean Barge 

Car/Bean Barge 

7/1 

4/4 

7/1 

4/4 

7I1 

5/3 

0.93 

0.93 

0.81 

0. 90 

0.90 

0. 92 

0.27 

0. 47 

0.25 

0.17 

0.11 

0.12 

A11 Sar1ip les 	 0.23 

I 
Table 9 

Number 0f 

Positive Reactions SKIN PRICK TESTS and RAST TESTS 

Skin 

Tests 

4~ 

kAST~ Materi a 1 Tested 

Histamine (positive control) 

0 Salir.e (negative control) 

15 l ** Cracker aspiration baghouse: Soybeans and dust from 

the cracker aspiration baghouse. Beans have come from 

the dryer to a conveyor that feeds the cracking rolls 

and have not yet been de-hulled. 

13 l ** Truck dump dust: Mainly dust (not beans) scooped up 

fron1 around truck dump area (i . e., dust from raw 

soybeans). 

l ** Head house. 0-27: Collected directly from the floor 

beneath the 027 transfer belt to storage . Combined 

raw soybeans and dust from barges. railcars, trucks 

and storage tanks. Collected material was a maximum 

of three days old. 

1 ** Hulls: Finished product collected directly out of 

hatch of barge bei ng loaded. 


7 l ** Barge Dust: Main ly dust (not beans) scooped out of 


indentation in floor of barge being unloaded (i.e•• 


4 

dust from raw soybeans). 
 Soybean sample P-30: De-hulled, cracked beans taken 


from the P-30 "leg 11 

• (The main difference between
 _this sample and sample P-21 is that these are beans 

that have been de-hulled. Both samples should contain ' 

mainly the raw soybeans and its different physical 

states (whole and cracked beans) rather than a 

2 

significant amount of dirt and other foreign material. 

Soy meal: Soy meal (final product) taken from sample 

bucket under dispensing tube from the automatic 

1 

sampler in the truck loading operator's house . Soybean sample P-21: Soybeans taken from the P-21 

"cracked bean leg , " which conveys beans that have been 

stored in the Head House. dried (possibly more than , 

l 1 ** 

oncei, scalped, cracked, but not de-hulled. 

Soybean pods: Sample of mainly soybean pods, taken 

from the corner of the floor of a barge being unloaded. 


l 1 ** So beans from half-full bar e: Sample of mainly raw 


soybeans i.e., not with dust, debris, pods, etc.), 


from bar.ge being unloaded . 
 l l ** Cor,1mercial soybean : Commercially available allergy 


test. 


(Continued) 
Table 9 (continued) 

Number of 

Positive Reactions SKIN PRICK TESTS and RAST TESTS 

Skin RAST 


Tests Tests Material Tested 


11 Mixed insects 


11 2 ** Dust mites 


5 Grain mites 


4 Peni cil l um 


1 Cladosporium 


1 Al ternari a 


1 Aspergi 11 is 


0 Fusarium 


0 Cephaspori um 


2 Grass 


2 Corn 


2 Pyrethrum 


2 RagWeed 


2 Wheat 


l Barley 


0 Oat 


1 Cat 

1 Rat urine 

2 House dust (RAST only; no skin prick test) 

** RAST test also performed. 

One participant had all the positive RAST tests to soybean products, plus 

an extreme elevation of serum total IgE, and a positive skin test response 

to Aspergillus. The diagnosis of chronic pulmonary aspergillosis, a 

disease which may or may not be work-related in a given individual, was 

consi dered. He was instructed to seek consultation with a private 

physi cian. The positive RAST and skin tests could be due to non-specific bindi ng of IgE, not allergy to soybean products. 

! 
Table 10 

Uoctor's Doctor 1 s PEFR Skin Tests Total RAST 

flio. lJiagnos. i s _O_ia_.g.._n_o_s__s_A_to_.p.._.y~·l __ V_a_r_ia_b_i_l_i_t,,..y_I_n_s_e_c_t_s_S_o_,.y_b_e_a_n_s__ l_.g'-E__Te.;;...;....;...s t 

l 
 2.8 - 8.9 + + 

i 
 2. 6 - 9. 4 + 

3 oronc11i tis* 
 5. 8 -18.l 

4 Occ-As Occ-Rh 


5 
 1.5 - 6.2 

6 ucc-Rh 
 1.4 - 8.4 

7 


8 * 
 1.5 - 3.1 

9 Occ-As 0 - 6.5 + + 

lG Ucc-As Occ-kh 

11 

12 Occ-As 1.8 - 3. 7 

13 Occ-As ucc-Rh Yes 1.7 -13.1 + + +++ +(8 soy) 

14 

15 2.1 - 4.3 + 

11.> Occ-As 

17 N-Ucc-As N-Occ-Rh 

18 0 - 5. 5 + + 

19 3. 0 - 5. 2 + + + 

2u Occ-Rh 2.5 - 4. 9 

21 Occ-As 

n Occ-As 
 + 

23 
 2.2 - 3. 7** 

24 N-Gcc-Rh 
 5.2 -11.9 + + 

25 Occ-As 
 2.0 - 5.8 

(continued) 

* Interviewed in March, 1985. Excluded from "possible asthma" and "possible 

rninii:is" evaluations. 

** une aberrant PEFR determination excluded from analysis. 

Atopy: A person was defined as atopic if he had a positive skin test to one 

of tile following three common aero-allergens: grass, ragweed, or cat. 
Table 10 (continued) 

l.ioctor's uoctor's PEFR Skin Tests Total RAST t~o. Oiagnosis l.Jiagnosis Atopy? Variability Insects Soybeans IgE Test 

2b Ucc-As 4.4 -21.2 

27 3. 0 - 4. 6 + 

2~ Occ-As 3. 3 - 8.3 + 

29 

JO 6. 8 -16.8 

31 + + 

3L N-ucc-As 1"1-0cc-Rh 

33 N-Occ-As 1.7 -10.7 

34 Occ-As Ucc-Rh 3.5 -15.1 

35 Occ-A s Occ-Rh 3. 2 -10.3 

36 N-Ucc-kh 

37 4. 0 - 15 . 0 
 J~ N-ucc-As 
 J~ 0 - 5.1 


40 Yes + + + +(2} 


41 ucc-Rh 3.1 -14.0 


42 1.3 - 5.4 + + 


43 Occ-As 2. 9 - 7.1 + + 


44 N-Occ-As Occ-Rh 2. 6 - 5.2 


45 Occ-As N-Occ-Rh ---------no data--------­

46 N-Occ- As Occ-Rh 


47 Occ-Rh Yes 10.0 -28.l + 


48 2. 9 - 2.9 + + 


49 N-Ucc-As Occ-Rh 1.4 - 13.6 


50 + + + 


AtoEy: A person was defined 

of the following three common 

as atopic if he 

aero-allergens : 

had a positive skin test to one 

grass, ragweed , or cat. 
Table 11 

Work-related Mean Difference in Percent 

Lower Resp. of Predicted FEV1, 

Tract Symptoms Number Post-Shift minus Pre-Shift 

Yes 14 0.79% 


No 24 -2.00%

I 

l 

l 


I 

l 


l 


I 


l 


l 

Table 12 


TASKS TO WHICH WORK-RELATED LOWER RESPIRATORY TRACT SYMPTOMS (LRSx) CASES ATTRIBUTED THEIR SYMPTOMS 


Task 1 Task 2 Task 3 

Ou st Dust Dust 

ID If Category Job Category Job Category Job 

4 R unload bean barge R unload railcars E load railcars 

9 R unload bean barge R Head house no response 

l (J 

lL 

13 

lo 

r~ 

R 

R 

I< 

unload bean barge clean-up 

Head l1ouse 

Head house 

R 

0 

I< 

0 

pull beans from tank 

clay tank 

unload rail & barge boiler room chemical 

E 

0 

R 

load rail with ~eal 

extraction 

unload rail & barge 

no response 

d 

t:.~ 

R 

R 

Head house 

Head house 

R 

£ 

raw bean dust 

mea 1 house c 

no response 

prep house ~!:> 

2b 

R 

R 

unload bean barge unload rail 

E 

R 

load rail 

sweep tunnel 

£ 

E 

load meal 

load railcars 2~ 

34 

R 

E. 

unload bean barge load rail 

R 

E 

unload rail 

load truck 

R 

R 

unload truck 

unload barge 

35 R shoveling beans R clean-up c prep building 

43 

45 

R 

R 

clean-up in prep 

pull beans-tunnel 

0 

R 

clay tank 

Head house 

c 

R 

clean-up 3rd floor prep 

unload barge 

R = Raw dust exposure 

E = Extracted dust exposure 

C = Cleaner dust exposure 

U = Other 
.. - - - . - -- ... -- ---- - - -- .. ­

Table 13 

TASKS TO WHICH ''PROBABLE OCCU~ATIONAL RHINITIS" CASES ATTRIBUTED THEIR SYMPTOMS 

Task 1 Task 2 Task 3 

Dust Oust Dust 

ID # Category Job Category Job Category Job 

4 R unload bean barge R unload railcar E load railcar 

6 

lU 

R 

R 

unload bean barge 

unload barge &rail 

R 

R 

unload railcar 

pull beans-tunnel 

R 

E 

unload trucks 

load barge &rail 

13 R unload bean barge R clean out dryers E loading meal 

20 0 grindingflakingrolls R drags in Head House E drags in meal house 

34 

3b 

41 

E 

R 

R 

load railcars 

shoveling beans 

unload bean barge 

E 

R 

R 

load trucks 

clean-up 

work in baghouse 

R 

C 

R 

unload barge 

prep building 

clean-up 

44 

46 

R 

R 

blowing dust 

unload barge 

R 

R 

measurestoragebins 

unload railcar 

R 

R 

pull samplesfromdryer 

un 1oad 'truck 

47 

49 

R 

R 

unload barge 

cracking roll dust 

E 

E 

load rail 

meal dust 

E 

R 

load truck 

clean-up 

R = Raw dust exposure 

E = Extracted dust exposure ~ = Cleaner dust exposure 

0 = Other 

., 


i 
Table 14 

Chang1:s is Cross-shift Spi rom~t1 y, on First Dly Back at Work 

Change in Change in 

Percent of Percent of Change in Category Predicted Predicted FEV1/FVC 

(N} FVC FEV1 Ratio 

Mean

Respirable

Dust Level

on First

Day Back 

Total Group -0.04 -1 .09 -0. 01 (46 workers) 

Raw Dust 

Exposure +l. 60 +0.40 -0.01 (15 workers) 0.25 mg/m3

Cleaner Dust 

Exposure +0.08 -1. 67 -0.01 (12 workers) 0.07 mg/m3

Extracted Dust 

Exposure -3.25 -2.75 +0.01 (4 workers) 0.07 mg/m3

Cleaner and 

Extracted Dust 

Exposure 

Categories 

Combined -0.75 -1. 94 -0.01 (l 6 workers) 0.07 rng/m3

I 
Table 15 

Stepwise Regression of Day 1 Pre-Shift FEV1 percent 

predicted on Pack-years of smoking and Total Dust Expos~re 

Parameter Regression P-value Model R2 

Coefficient 

Intercept 97 .26 0.061 

Pack -Years -0.245 0. 0990 

Total Dust did not meet the 0.15 significance level for entry into the model 

Tabl e 16 

Stepwise Regression of Day l Pre-Shift FVC 


Percent Predicted on Pack-years of smoking and 


Duration of work in Departments l and 2 (Duration) 


Parameter 	 Regression P-val ue Model R2 

Coefficient 

Intercept l 01 .69 	

Duration -0. 949 0.0603 

0.078 

Pack-Years did not meet the 0. 15 signifi cance level for entry into the model 


Table 17 


Stepwise Regression of Day l Pr e-Shift FEV1 


Percent Predicted on Pack-years of smoking and 


Duration of work in Departments 1 and 2 (Du ration) 


Parameter 	 Regression 

Coefficient 

P-value Model R2 

Intercept 

Duration 

l 01 . 59 	

-1 .038 0.0665 

0.074 

Pack -Years did not meet the 0.15 signi fi cance level for entry i nto the model 
Figure l 

Dired Exlrodion 

Preparation 

,_, ...... 

P-2 S<at. 


P-3 Crad.. Mil 


P-4 Meah Co1Mlli1 •r 

P-5 Floliftg Mii 

Solvent Extraction 

Meal Handling E·1 •- Aelie Et.votor E-7 1d Stage FvopofC1tor 

E-2 btrocfor '-ecl ConwJ« E-t Id llo91 Co~ns•r 

M-1 l~ Meal Coo&.r E-l Starioe•y lo..et btroctor E-9 2nd Slog• Evoporolot 

M-7 Meal Grtnder E-4 Spetet Flolie Elevator E-10 2rd Slog. Condenser 

M-3 M.of S<r..tt E-5 O.solventizer Toa1h1r E-11 final Oil Strrpptr 

E~ Vop« Scrubbet E-12 Vncuum Cond..,.uer 

Typical Soybean Processing Diagram