**UNTTEDSTATESE~ONMENTALPROTECTIONAGENCY** WASHINGTON,D.C. 20460 RECEIVEl.:.

February 5, 1998 OFFI<;:EOF PREVENTION,PESTICIDES

**AI~<'D** TOXICSlJBSTANCES

SUBJECT: Review of Methyl Parathion Incident Reports

_ DP Barcode D242333, Chemical #053501, Reregistration Case#0153 FROM: Jerome Blondell, Ph.D., Health Statistician Chemistry and Exposure Branch 2 

### r.u ,_0

### e Health Effects Division (7509C)



### ~**~**

THRU:

TO:

BACKGROUNDMonica F. Spann, MPH, Environmental Health Scientist chemistry and

**EXJ?o~u:e** Branch 2

**1\\-:-r~. ~** 

# _ 1 _ ::r:.._ ----- Health Effects

**D~v~s~on** (7509C) · ·f Susan

## v. Hummel, Senior Scientist

. l, , /1 .A_,L-1___;

_

## ~~""'~ Chemistry and Exposure Branch 2

**-~·-·-** Health Effects Division (7509C) Jonathan Becker, EnvironmenLal Health Specialist Reregif?tration B'ranch 2· Health Effects Division (7509C)

The following databaseshavebeenconsultedfor thepoisoning incident data on the active ingredient Methyl Parathion (PC Code: 053501): 1) OPP Incident Data System {IDS)

- reports of incidents from various sources, including registrants, other federal and state health and environmental agencies and individual

. consumers, submitted to OPP since 1992. Reports submitted to the Incident

# -7 DataSystem

**represent_~I1ecd<?t~l** re2_9rtsorallegationsonly, unless / otherwise stated. Typically no conclusions

. can be -drawn

. implicating fhe pesticide as a cause of any·of.the reportedhealth effects. Nevertheless, sometimes with enough cases and/or enough documentation risk mitigation measures may be suggested. 2) Poison Control Centers

- as the result of

**Data~Call-Ins** issued in 1993, OPP receivedPoisonControl Centerdatacoveringtheyears 1985 through 1992 for 28 organophosphate and carbamate chemicals. Most of the national Poison Control Centers (PCCs) participate in a national data collection system, the Toxic Exposure Surveillance System which obtains data from about 70 centers at hospitals and2
a national data collection system, the Toxic Exposure Surveillance System which obtains data from about 70 centers at hospitals and universities. PCCs provide telephone consultation for individuals andhealthcareprovidersonsuspectedpoisonings, involvingdrugs, household products, pesticides, etc. 3) California Department of Food andAgriculture (replacedby the Departmen,t of Pesticide Regulation in 1991) California has collected uniform data on suspected pesticide poisonings since 1982. Physicians are required, by statute, to report to their local health officerall occurrences of illness suspected of being related to exposure to pesticides. The majority of the incidents involve workers. Information on exposure (worker activity), type of illness (systemic, eye, skin, eye/skin and respiratory) 1 likelihood of a causal relationship, and number of days off work and in the hospital are provided. 4)

. National Pesticide Telecommunications Network {NPTN)

- NPTN is a toll..:free information service supportedbyOPP. Arankingof the top 200 active ingredients for which telephone callswere received during calendaryears 1984-1991, inclusive has beenprepared. The total number of calls was tabulated for the categories human incidents, animal incidents, calls for information, and others.
METHYL PARATHION REVIEW I: Incident Data System Please note that the following**ca~es** from the IDS do not have documentation confirming exposure or health effects-i.n1.less otherwise noted. Incident# 000578 001 Apesticide incident occurred in 1993, when nineteen workers were exposed to methyl parathion and two other pesticides when entering an apple.orchard two or three days after application to thin the fruit. The other two pesticides, calcium chloride and Systhane/Mycloburanil, arenotcholinesteraseinhibitors. Theyall reported experiencing some combination of headaches, diarrhea, nausea, and one worker had a bloody nose. In another incident in the same field, sixteen workers {perhaps of the original 19) reentered the area 49 hours after methyl parathion (Penncap M) was sprayed·and a few complainedof illness. The next day all sixteen workers were complaining of illness (headache, nausea, diarrhea) and left the field. No one sought medical treatment, so blood cholinesterase was not measured. No further information on the disposition of.the case was reported.3 Incident# 000894 004**~pesticide** incidentoccurredin 1992, whenseveral inspectors found more than 200 gallons of methyl parathion in a basin and experienced burning throats, sore eyes, and fatigue. No further information on the disposition of the case was reported. Incident# 001280 004 A pesticide incident occurred in 1994, when a veterinarian smelled a container with methyl parathion and became ill. No further information on the disposition of the case was reported. Incident# 001769 001 A pesticide incident occurred. in 1994, when a woman was sprayed with methyl parathion by an aerial applicator and experiencedblurredvision, disorientation, weakening inthe legs, and memory lapses. She reported that the symptoms persisted for eleven months.
Incident# 002225 001 Apesticide incident occurreQ in 1995, when an individual was packaging containers of methyl parathion and experienced nausea. No further informationonthe dispositionofthe casewas reported. Incident# 002431 001 Apesticide incident occurred in·1995, when a three year old boy was exposed to methyl parathion after a pig rooted out a hole in the ground which had previously been an old farm surroundedby a fence. The boy played in this same area and experienced vomiting. No further information on the disposition of the case was reported

.. Incident# 002479 001

. Apesticide incident occurredin 1995, when a manwas sprayed withmethyl.parathionthatwas appliedaeriallyandtwoweeks later experiencedconvulsionsanQseizures. Symptomsduringthe twoweek period were not reported. No further information on the disposition of the case was reported. 'Incident# 002922 001 A pesticide incident occurred in 1995, when a man was accidentally sprayed with methyl parathion that was applied aeriallyto a cotton field. Specific symptoms were not mentioned. No further informationonthedispositionofthecasewas reported. Incident# 003599 001 The Minnesota Department of Agriculture surveyed state enforcement agencies t'o determinewhat pesticideswere involvedin spraydrift. Among the thirty-two statesrespondingto·the survey, there was a .total of 2,681 cases of drift complaints related to specific pesticides. Methyl parathion was responsible for 7 complaints or less than one percent of the total.4 Incident# 003976 001 A pesticide incident occurred in 1996, when a crop advisor, who was scouting corn fields 48 hours after spraying with methyl parathion. He experienced nausea, blurred vision, and excessive salivation. He did not see a doctor but remained in bed several days. No further information on the disposition of the case was reported. Incident# 004420 001 A pesticide incident occurred in 1996, when a woman and her son were sitting on their back porch and were sprayed with methyl parathion. Thewomanexperiencednausea, chesttightness, soreness over her entire body, and body tremors. The son experienced diarrhea, skin irritation, and headaches. No further iriformation on the disposition of the case was reported. Incident# 004439 142 Apesticide incident occurred in 1996, when an individual was drenchedwithmethyl parathion and_gied. Despite repeated followup

### ..!!2--infQJ;:mat;i.on could be obtained

**~.9-** verify this incident.
II. Poison Control Center Data Methyl Parathion was one of 28 chemicals for which Poison Control Center (PCC) datawere

**requ~sted.** The following text and statistics are taken from an analysis-of these data; seeDecember 5, 1994 memo from Jerome Blondell to Joshua First. The 28 chemicals were ranked using three types of measures: (A) number and percent occupational and non-occupational adult exposures reported to PCCs requiring treatment, hospitalization, displaying symptoms or serious life-threatening effects; (B) Californiadata for handlers and fieldworkers comparingnumberof agriculturalpoisoningstoreportedapplications; and {C) ratiosof poisonings and hospitalization for PCC cases. to estimated pounds reported in agriculture for pesticides used primarily ln agriculture. A. Occupational and Non-occupational Exposure There were

**~** total of 274 methyl parathion cases in the PCC data base. Of these,

**10~** cases were occupational exposure; 91 (89%) involved exposure to methyl parathion alone and 11 {11%) involved exposure tomultiple chemicals, includingmethylparathion
..There were a total of 146 adult non-occupational exposures; 113 {77%) involved this chemical alone and 33 (23%) were attributed to multiple chemicals. 1

1 Workers who were indirectlyexposed (not handlers) were classifiedas nonoccupational cases.5 In this analysis, four measures of hazard were developed based on the Poison Control Center data, as listed below. 1. Percent of all accidental cases that were seen inorreferredto a health care facility (HCF)

. 2. Percent of these cases (seen in or referred to HCF) that were admitted for medical care. 3. Percent of cases reporting symptoms based on just those cases where the medical outcome could be determined. 4. Percent of those cases that had a major medical outcome which could be defined as life-threatening or resulting in permanent disability. Exposure to methyl parathion alone or in combination with other chemicals was evaluated for each of these categories, giving a total of 8 measures. Aranking of the 28 chemicals was done based on these measures with the lowest numberbeing the most frequently implicated ih adverse effects. Table 1 presents the analyses for occupational and non-occupational exposures.6 Table 1: Measures of Risk From Occupational and Non-occupational Exposure toMethyl ParathionUsing PoisonControl Center Data from 1985-1992a Occupational Exposure Non-occupational Exposure

Percent Seen in HCF Single chemical 81.35 (68.2) 58.4* (44.0) exposure Multiple chemical 82.45 (69.8) 63.7*6 (46.1) exposure Percent Hospitalized Single chemical 9.5* (12.2) 9.1* (9.9) exposure Multiple chemical 13.1* (14.3) 14.0* {12.6) exposure Percent with Symptoms Single chemical 72.7* (85.8) 80.0* (74.0) exposure Multiple chemical 75.0* {85.8) 81.3*7 {75.2) exposure Percent with Life-threatening Symptoms Single chemical 0.0 (0.0)- 0.0* (0.0) exposure 

## - Multiple chemical 1.2 (0.5) 0.0* (0.05) exposure a Extracted from Tables 2, 3, 5 and 6**~n** December 5, 1994 memo from Jerome Blondell to Joshua First; number in parentheses is median score for that category * Top 25% of chemicals are ranked with a superscriptof 1 to 7 Includingexposuretomultiplechemicals, methylparathionhad the fifth highest percent of occupational cases .seen in a health care facility (Table 1)

. On other measures of hazard (percent hospitalized, percentwith symptoms or life-threateningsymptoms), methyl parathion had percents similar to the median 'for other cholinesterase-inhibitors, sometimes higher and sometimes lower. 

### _j
B. Ratios of poisoning

- California Data The in<;:idence of·systemic poisoning cases in agricultural workers reported to the California was**comp~red** to the number of applications of methyl parathion. Those calculations, along with themedian score for a total of 29 pesticides, arepresentedinthe Table 2 below.7 Table 2: Systemic Poisonings/1,000 Applications in Selected Agricultural Workers Exposed to Methyl Parathion in California, 1982-1989a Number Poisonings/1,000 Appl. (N) Poisonings/1,000 Appl.(N)

Pesticide of Primary Pesticide Only Multiple Pesticide Appl. Exposure Handlers Field Total Handlers Field Total Workers Workers Methyl 4S,S97 .04 (2) .00 (0) .04 .09 (4) .04 (2) .13 Parathion (2) (6) Median .21 .20 .41 .44 

### .so 1.02 a Extracted from Table AS

**~n** December S, 1994 memo from Jerome Blondell to Joshua First; number in parentheses is the observed number of poisoned cases. Methyl Parathion had much lower ratios of handler poisonings and field worker poisonings per 1,000 applications in California; regardless of whether exposures to mixtures were included or not. For total poisoning per 1,000 applications where methyl parathion was deemed the primary cause of the incident, only two other pesticides (bacillus thuringiensis and permethrin) had lower ratios. This is an unusually good record for an organophosphate insecticide, suggesting that worker practices in place in California from 1982 through 1989 were both safe and effective. C. Ratios of Poisoning 

## -·u.s. Poison Control Data Active registrations ofmethyl parathionare for agricultural use exclusively. Ratios of the number of occupational Poison Control Center exposures to the reported pounds of the chemical used2 were calculated. The results for methyl parathion and the median for the 15.agricultural.chemicals included in the analysis are presented

# in the Table 3 below.
Table 3: Ratios of Methyl Parathion Poisonings (PCC Data, 1985- 1992) to Reported Usea Exposure Poisonings .Health Care Hospital Admitted Pesticide Per Use Per Use Referral Per Use Cases Per Use Methyl # .013* .008* .010* .001* Parathion
-· Median .033 .013 .027 .004 a Extracted from Table 9

**~n** the December 5, 1994 memo from Jerome Blondell to Joshua First * Top 33% of chemicals are ranked with a superscript of 1 to 5

2 Gianessi, L.P., Puffer, C.A. Insecticide Use in U.S. Crop Production. Resources for the Future, Washington, D.C., 1992·. 

### -,8 Among pesticides used exclusively in agriculture, methyl parathionhad the third lowest ratio of exposures, poisonings, and treatment to

**estirn~ted** pounds active ingredient reported in use (Table 3}. Methyl parathion had second lowest ratio of hospitalized cases per estimated pounds used. Based on these measures, methyl parathion appears to be much less likely to be involved in potential poisonings than other organophosphate and carbamate insecticides. D. Exposure in Children A separate analysis of the number of exposures in children five years of age and under from 1985-1992 was conducted. For methyl parathion, there were 26 incidents; 23 involved exposure to methyl parathion-alone and 3 involved other pesticides as well. Because of the relatively small number of cases, no statistical comparisons were--ma-de with other organophosphates and carbarnates.
E; Environmental and Misuse accidents The American Association of Poison Control Centers (AAPCC) provideddata on over 100,000 exposures from 1985 through 1992 for 28 pesticides. A search was performed on this data for those pesticideswithno significanthorneuse, but largeagriculturaluse ('n = 15)

. Only exposures where the r·esidence was the site of the exposure andthepesticideprodUctwas the soleproduct involvedin the exposure were included inthe analysis. The table below shows the results where reason was environmental or misuse. AAPCC defines these terms as follows: Environmental: any passive exposure that results from man-made contamination of the environment, e.g. exposures to contaminated water resulting from improper disposal of chemicals, passive inhalation of toxic fumes or gases as a result of discharge at a plant-or a "HazMat" incident

.. Misuse: 

### An accidental exposure which results from the improperor incorrect use of a substance where therapeutic or beneficial results were intended. The ocher commonly used "reason" categories are general, occupational, unknown, and intentional (includes suicide and abuse)

. General is defined as: all unintended poisonings or exposures that_are not specifically defined by other categories, including most accidental exposures to children, bites, stings, plant exposures and unintentional food poisoning. Obviously there is considerable 'gray area' between these categories and many scenarios can be imagined where different poisonspecialistswouldassigndifferentcategories. Forexample, spray drift could be counted as environmental or misuse and 

## /9 probably accounts for the majority of cases recorded. The purpose of this analysis was to find out if it might be used to identify agricultural pesticides illegallyapplied in the home environment. The other keyproblem withAAPCC data, particularly severe in this case, is the lack of representation. in certain states. Thirteen states had little or no coverage byAAPCC during the time period of interest. They were Nevada, Oklahoma, Texas, Arkansas, Mississippi, Illinois, Iowa, North Carolina, South Carolina, Delaware, Connecticut, Vermont and Maine. In particular, the absenceofdata fromMississippi, the Carolina, Arkansas, Texas and 

# i Oklahoma is likelytomiss a substantialportionofmisuseproblems due to methyl parathion.
Table 4. AAPCC exposures for agricultural pesticides reported in residences due to environmental exposure ·or misuse, 1985-1992 (ratio = environmental + misuse/ pounds active ingredient)

.

Pesticide Environ- Env. + Pounds ai E+M/P mental Misuse Misuse 1989-91 ratio aldicarb 30 6 36 5000 7.2 azinphosmethyl 16 3 19 3000 6.3 carbofuran 12 19 31 1500 20.7 dicrotophos 2 2 4 ethoprop

. 2 0 2 750 2.7



### - fenamiphos 0 0 0 800 0.0 fonophos i2 1 13 methamidophos 15 0 15 1230 12.2 methidathion 1 1 2 520 3.8

.. methyl 29 5 34 8180 4.2 parathion mevinphos 3 0 3 420 7.1.



# . phorate 3 5 8 2902 2.8 profenofos -· 0 0 0 900 0.0 sulfotepp 7 0 7 terbufos


### . 4 4 8 The conclusion from examining Table 4 is that the categories. for environment andmisuse cannotbeusedtoidentifyagricultural pesticides, like methyl parathion, that may be applied indoors.10 III. California Data

- 1982 through 1995· Detaileddescriptions of 18 cases submittedto the California Pesticide Illness Surveillance Program (1982-1995) were reviewed. In 7 of these cases, methylparathionwas usedalone andwas judged to be responsible for the health effects. Only cases with a definite, probable orpossible relationshipwere reviewed. Methyl parathion ranked 90th as a cause of systemic poisoning in California (1982-1994)

.

**Tabl~** 5 presents the types of illnesses reported by year. Table 6 gives the total number of workers that took time off work as a result of their illness and how many were hospitalized and for how long.
Table 5. Cases Due to Methyl Parathion Exposure in California Reported by Type of Illness and Year, 1982-1995
Illness Type Year Systemica Eye Skin Respiratory Total 1982 1 1


## - - 2 1983 1 

### - - 

## - 1



### - 1984 

### - - 

## - - -
. - 1985 

## - - - 

## - - 1986


## - - 

## - - - 1987 1


## - - 

## - 1 1988


## - - 

## - - - 1989 

## - - - - - 1990 2 

## .. - - - 2 1991 

## - - - .- 

## - 1992 1


## - - - 1 1993

**~** 

## - - 

## - 

# - -

.1994 ..
- 

## - - 

# - - 1995 

## - - - - - Total 6 1 

## - - 7

a Category includes cases where skin, eye, or respiratory effects were also reported11 Atotal of 6 persons had systemic illnesses or 86% of 7 cases. Five of these workers took between two and five days off work as a result of their illness as shown inTable 6 below. One worker was hospitalized for four days after spraying the insecticide inside a greenhouse. A variety of worker activities were associated with exposure to methyl parathion as illustrated in .Table 7 below.

Table 6. Number of Persons Disabled (taking time off work) or Hospitalized for Indicated Number of Days After Methyl Parathion Exposure in California, 1986-1995.
Number of Persons Number of Persons Disabled Hospitalized One day - 

### - Two days 2 

## - 3-5 days 3 1 6-10 days 

### - - more than 10 days 

## - - Unknown

- 

## - . 

## -

.
Table 7. Illnesses by Activity Categories for Methyl Parathion Exposure in California, 1986-1995
Illness Category Activity Systemicb Eye Skin Respirat'ory Tc>tal Cat

**ego~** Applicator 2 1 

# - - 3 Driftexp 2 

## - 

# - - 2

- Other 2 

## - 

# - - 2



# . Total 6 

## - - - 7

a Dr1.fte = e osure··to xp xp pest1.c1.de t :tat has dr1.fted from 1.ntendec targets; Other= other occupational exposure b Category includes cases where skin, eye, or respiratory effects were also reported According to the above activity categories,·applicators (two byhandandoneby sprayrig) were associatedwiththree illnesses. The most serious case experienced muscle spasms, vomiting,



# \~~ \ '**-~**
12 diarrhea, and abdominal pain and was hospitalized for four days. One of the cases classified as other was a person downwind from a spill, similar to the two drift exposure cases. These cases reported symptoms of headaches, difficulty breathing, nausea, diarrhea, vomiting, weakness, sweating, and itching around the mouth.
IV. NPTN On the list of the top 200 chemicals for which NPTN receivedcalls from 1984-1991 inclusively, methylparathionwasnot ·reported to be involved in human incidents. V. Literature Review Two incidents involving deaths have been reported in Mississippi from misuse of methyl parathion inside homes. The first incident reported in 1977 involved sevenof 13 members inone family who developed weakness, abdominal pain, nausea, vomiting, difficulty seeing, excessive sweating and salivation. The father of the rural farm family had taken some concentrated methyl parathion from a discarded drum and placed it in a nebulizer and then sprayed his home for cockroaches. A 26. year old,died as- a**--~** result of organophosphate poisoning confirmed by cholinesterase // testing. Inthe secondincident, themale live-incompanion sprayedthe house to control spiders. He hadobtaineda nearlyempty.container of methyl parathion from the farm he worked on and added water to it. He used a hand sprayer. to spray the solution on the inside upper walls of three of the four rooms (excluding the kitchen) in the house. The concentration in the hand sprayer was found to be three times that usedfor outdooragricultural application. It·was suspected that methyl ·parathion got into the food and drinking water, as well as .being present in the air and on surfaces. All seven children in·the home became ill and were hospitalized with confirmed cholinesterase inhibition. Two of the five children, a four year old and an elevenyear**~ld,** died. Numerous cases of exposure inside homes have been documented in Ohio,**Mi~higan,** Mississippi, Louisiana and elsewhere. These exposures have occurre.d due to illegal application by PCOs going door to door. Tci"tal number of people exposed from these applicationsnumber inthethousands andover 1,000peoplehavehad to be relocated while their home were decontaminated. The estimated cost of clean up exceeds $70 million. There_have been reports of symptomatic human cases and pets that have been adversely affected or died. However, these cases have not been confirmedbycholinesterasetestingandthe reportedcaseshave not been published in the scientific literature.

# 012848 13 VI. Conclusions Exposure tomethylparathioncan leadto systemic illness. In outdoor agricultural situations, theprimaryactivities associated withpoisoning are application and spraydrift. Compared to other organophosphate and carbamate insecticides, methyl parathion is associatedwith lesspoisoningwhen adjustedfor amount of use. To some extent the similaritybetweenthemethylparathionandthe far more toxic ethyl parathion (in terms of poisonings and deaths even afteradjusting foruse), mayhave resultedinworkers handlingany product with the 'parathion' name with greater care. Interior home use of methyl parathion has resulted in deaths in two separate incidents in Mississippi. Food or water contamination and an unusually high concentration used in the applicationprobablycontributedto thesedeaths which occurred in the 1970s andearly 1980s. Themore recent cases exposedprimarily in Ohio, Mississippi, and Louisiana have not been well documented or confirmed with cholinesterase testing. VII. Recommendations Numerous actions have already been taken to prevent use of methyl parathion in homes. For outdoor

**us~,** protective measures required for other organophosphate and carbamate. insecticides should be considered. Special attention should be given to protecting pesticide handl-ers andprevent·ing spray drift.

cc: Correspondence. Methyl parathion file (chemical rio. 053501) SRRD

- Emily Mitchell (7508W) RDI: BRSrSci:SHummel: