Environmental Health Perspectives • VOLUME 109 | NUMBER 5 | May 2001 533

Work Characteristics and Pesticide Exposures among Migrant Agricultural

Families: A Community-Based Research Approach

Linda A. McCauley,1 Michael R. Lasarev,1 Gregory Higgins,1 Joan Rothlein,1 Juan Muniz,1 Caren Ebbert,2

and Jacki Phillips3

1Center for Research on Occupational and Environmental Toxicology at Oregon Health Sciences University, Portland, Oregon, USA;

2Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA; 3Oregon Child Development

Coalition, Wilsonville, Oregon, USA

Pesticides are among the environmental contaminants that represent potential sources of

health risks (1). Although all populations

have a degree of risk in relation to pesticide

exposures from nonagricultural use and

through residues on food, there are certain

subgroups of the population with a higher

risk of exposure and potential health effects.

The special health concerns and research

needs of the migrant farmworker population

have been addressed by national groups

(2–4). Migrant farmworkers are among the

most disadvantaged, medically indigent persons and have the poorest health of any

group in the United States (5,6). The lack of

national research and hard data on migrant

and seasonal farmworkers has hindered

efforts to improve the health of this population (3). Occupational and environmental

diseases including health problems related to

pesticide exposure in this minority population warrant increased attention. 

Agricultural workers can inadvertently

carry hazardous materials home from work

on their clothes, skin, hair, and tools, and in

their vehicles. Because of the nature of agriculture and the proximity of homes to the

fields, it may be difficult to separate exposures at work and exposures at home. Studies

designed to characterize children’s exposures

to pesticides in the general population indicate that the largest number of pesticides and

the highest concentrations are found in

household dust compared to air, soil, and

food (7,8). Pesticide exposure can occur from

a number of sources such as contaminated

soil, dust, work clothing, water, and food, or

through drift—the deposition of a pesticide

off target. In many migrant farmworker communities, home sites are close to or surrounded by fields or orchards. Pesticides may

persist in indoor environments longer than in

outdoor soil due to the lack of degradative

environmental processes such as sun, rain,

and soil microbial activity. Investigations in

the last decade have documented levels of pesticides in homes of farmers and nonseasonal

farmworker families living within 200 feet of

an orchard compared to referent families (9).

The authors found organophosphate (OP)

compounds in 62% of household dust samples of agricultural families in Washington

State. There have been no published reports

of the pesticide residues in the housing of

migrant farmworkers. Factors specific in the

migrant farm-family environment could

potentially increase pesticide levels in the

home, specifically, the close proximity of

housing to the fields where spraying occurs,

the substandard housing in which migrant

families often live, the number of persons living in the dwelling, and inadequate laundry

facilities to cleanse clothing of pesticide

residues and multiple family members working in the agricultural fields. Almost one-half

of migrant farmworkers live in housing with

family members (10). Studies are needed to

document the exposure patterns of children

residing in crowded, substandard housing.

However, given the migratory patterns and

temporary labor characteristics of this population, they are often not studied in research

investigations.

Materials and Methods

The migrant Latino farmworker families

recruited for our project were obtained

through a community partnership with the

Oregon Child Development Coalition

(OCDC), a private, not-for-profit corporation with central offices located in

Wilsonville, Oregon. The OCDC was organized in 1971, under the name of the

Migrant Indian Coalition, to address the

needs of migrant and seasonal farmworkers

as well as Native American families. In 1975

the organization became the grantee for the

Migrant HeadStart (MHS) program in

Oregon. The OCDC directly administers

and operates MHS programs serving 1,800

migrant Latino children (from birth through

5 years of age) and their families at nine centers throughout Oregon. The program provides child care, medical, dental, and social

services during the migrant farmworker season (May–November). With nine centers

throughout the state, the program serves

40% of all 3–6-year-old migrant children in

the state and 75% of eligible children in the

Address correspondence to L. McCauley, Center for

Research on Occupational and Environmental

Toxicology at Oregon Health Sciences University,

L-606, 3181 SW Sam Jackson Park Road, Portland,

OR 97201 USA. Telephone: (503) 494-2501. Fax:

(503) 494-4278. E-mail: mccauley@ohsu.edu

All protocols in this study were conducted in accordance with Oregon Health Sciences University’s

institutional guidelines for the protection of human

subjects. 

This study was supported by a grant from the

National Institute of Environmental Health Sciences

(R21ES08707).

Received 26 September 2000; accepted 20

November 2000.

There are few data on pesticide exposures of migrant Latino farmworker children, and access to

this vulnerable population is often difficult. In this paper we describe a community-based

approach to implement culturally appropriate research methods with a migrant Latino farmworker community in Oregon. Assessments were conducted in 96 farmworker homes and 24

grower homes in two agricultural communities in Oregon. Measurements included surveys of

pesticide use and work protection practices and analyses of home-dust samples for pesticide

residues of major organophosphates used in area crops. Results indicate that migrant farmworker

housing is diverse, and the amounts and types of pesticide residues found in homes differ.

Azinphos-methyl (AZM) was the pesticide residue found most often in both farmworker and

grower homes. The median level of AZM in farmworker homes was 1.45 ppm compared to 1.64

ppm in the entry area of grower homes. The median level of AZM in the play areas of grower

homes was 0.71 ppm. The levels of AZM in migrant farmworker homes were most associated

with the distance from fields and the number of agricultural workers in the home. Although the

levels of AZM in growers and farmworker homes were comparable in certain areas, potential for

disproportionate exposures occur in areas of the homes where children are most likely to play.

The relationship between home resident density, levels of pesticide residues, and play behaviors of

children merit further attention. Key words: agriculture, azinphos-methyl, children, environmental exposure, environmental justice, migrant farmworkers, pesticides. Environ Health Perspect

109:533–538 (2001). [Online 14 May 2001]

http://ehpnet1.niehs.nih.gov/docs/2001/109p533-538mcccauley/abstract.html

CHILDREN’S HEALTH

Article
geographic areas where centers are located.

The OCDC is an established minority organization with proven ability to access and

serve minority populations.

In the summer of 1997, we obtained a

convenience sample of 96 migrant Latino

families who had preschool children enrolled

in MHS centers in Washington and Hood

River Counties in Oregon. Information was

obtained on the work characteristics of all

adult family members residing in the home,

self-reported protection practices at work

and upon coming home, and residential pesticide use. In a subset of families, we

obtained detailed information on the physical characteristics of their housing, and we

also obtained home dust samples for the

measurement of pesticides. Of the 96 families, 59 had carpets from which we could

obtain dust residues using our high-efficiency vacuum sampler. (We concluded that

wipe samples from uncarpeted floors would

give variable results.) Of the 59 families,

dust samples were collected from 49 homes.

The remaining 10 homes were not sampled

due to timing constraints and equipment

availability. No family refused access.

Target population. We recruited families

from the MHS centers in two agricultural

areas of northwest Oregon. Hood River

County has primarily fruit orchards, and

Washington County has a combination of

berry and vegetable crops and nurseries.

Washington County is in the rural surburban area of Portland, Oregon. Hood River

County is approximately 70 miles east of

Portland. Families arrive earlier in the year

in Washington County due to the months

of harvest. In 1997 the MHS center in

Washington County enrolled approximately

110 families with children ≥ 3 years of age.

Approximately one-half of the families live in

migrant labor camps and one-half rent other

types of housing in the area. The average

enrollment in the MHS centers in Hood

River County is 80–100 families. The housing for migrant farmworker families in Hood

River County tends to be a small number of

temporary structures on individual grower

property and rental units in the small towns

nearby. Large migrant labor camps are not

seen frequently in the Hood River area. 

Recruitment of families was carried out

by a number of steps. In Washington

County, recruitment began when we placed

a poster advertising the study in the MHS

center. As families moved into the area,

MHS enrollment sheets were reviewed each

week to identify new eligible families.

Spanish-speaking research assistants and

OCDC staff provided study information at

two health fairs, where children enrolled in

the MHS were receiving their health screenings and also at an MHS open house on the

first day of classes. As more migrant families

began arriving at the labor camps, recruitment was done by contacting families when

they enrolled their children or visited the

center, or by visiting the homes of families

with children enrolled in the MHS. Similar

recruitment methods were used in Hood

River County. We continued recruitment

with the goal of obtaining 50 families from

each area. In no circumstance did we recruit

multiple families who shared the same housing, although it was common to find homes

where more that two adults were living in

the home and working in agriculture.

Recruitment ended when we had met our

recruitment goals or when the families began

moving to other farming communities. 

Measurements and instruments. As a

major component of our project, we focused

on the need to better understand the underserved migrant farmworker community and

to incorporate feedback from representatives

of that community at every step of the

research process. We had parent representation on our research advisory committee.

The members of the migrant community

and the parents of migrant children provided

substantive input on when and who should

contact families for participation, the appropriateness of advertisements, and the appropriateness of the teams that are put together

to collect data in migrant family homes. 

The primary language of the Latino

migrant population in Oregon is Spanish,

and many speak indigenous languages from

Mexico or other Latin American countries.

Few families speak English as a secondary

language. To increase the cultural appropriateness of our study methods and instruments, we completed multistep translations

and interpretations of all study instruments

and consent forms. We then modified the

forms to be read more easily to potential subjects. Questionnaires and consent forms were

pilot-tested with migrant families for understanding of the content. All unclear examples

or sentences in questionnaires were removed

or substituted with content that was relevant

to the migrant families’ experiences. 

Four questionnaires were used: the

Demographics Sheet, the Agricultural Work

Practices Questionnaire, the Pesticide

Inventory, and the Pesticide Use Survey.

The Demographic Sheet was developed for

the purposes of this study and contained

information on the number of members

within the family unit, and the age, sex,

years of education, the type of housing, and

the employer(s) of the parents. We also

developed the Agriculture Work Practices

questionnaire, which contained items on

type of work (e.g., thinning, picking, packing, pesticide application, flagging), type of

crop(s), hours worked per week, use of insect

repellents, use of protective clothing, bathing

and laundry habits, and wearing of work

clothes outside of fields. 

We developed a pesticide inventory with

which we could record observations on the

presence and storage of pesticides in the

home, as well as the housing structure, ventilation, the type of cooling system, and the

presence of carpeting. The Pesticide Use

Survey was developed to obtain information

from the family on home pesticide use and

storage, the use of precautionary actions, and

adverse effects from the application of pesticides in the home. All of these questionnaires were pretested on Spanish-speaking

adults and have been used or adapted for

other studies with migrant farmworker and

grower populations (11–14).

Land use information (including proximal crops) was collected during home visits

and with the use of digitized local tax-lot

datasets. We used a geographic information

system (GIS) database (MapInfo; MapInfo

Corporation, Troy, NY) to create maps and

analyze the spatial distribution of homes and

land use proximal to housing. We also collected farm and labor camp boundaries and

distances from family housing to crops using

a handheld global positioning system (GPS)

unit (Apollo GPS; UPS-Aviation Technology,

Salem, OR). Data were also collected on a

smaller scale to create a layout of the

dwellings of families residing in labor camps

(i.e., housing, showers, cooking facilities, etc.)

and the layout of the individual cabins (windows, doors, stove, etc.). We collected additional descriptive data including housing

density, housing structure, shower, bathroom,

laundry, and cooking facilities. 

We collected house dust samples in

dwellings with carpeted floors using the

HVS3 High Volume Small Surface Sampler

(Cascade Stack Sampling Equipment, Bend,

OR). A surface wipe procedure using glass

fiber filters (Fisherbrand G6 glass fiber circles;

Fisher Scientific, Pittsburgh, PA) and cotton

swabs wetted with isopropanol (Mallinkcrodt,

Chesterfield, MO) was used to collect samples

from dwellings with hard floor surfaces. All

samples and wipes were transferred to glass or

teflon bottles, placed immediately in an insulated, ice-cold container, transported to the

laboratory within 12 hr of collection, and

stored at –20°C pending analysis within 12

months of collection.

Dust samples and glass fiber filters/cotton swabs were prepared and analyzed using

sonication, gel permeation chromatography,

and gas chromatography/mass spectrometry

(GC/MS) methods adapted from Simcox et

al. (9). All analyses were conducted with a

Hewlett Packard 5890 Series 2 gas chromatograph equipped with a 5972 Mass

Selective Detector and autosampler (Agilent

Children’s Health • McCauley et al.

534 VOLUME 109 | NUMBER 5 | May 2001 • Environmental Health Perspectives
Technologies, Palo Alto, CA). None of the

pesticide residues that we measured were

above detection limits [0.1 ppm for azinphosmethyl (AZM), 0.05–0.1 ppm for other pesticides of interest] in solvent, glass fiber filter,

and cotton swab blanks (data not shown).

Recovery efficiencies of spiked dust samples

demonstrated a mean recovery of 98% for

AZM and 94–98% for other pesticides of

interest. Analytical results reported in this

paper are not corrected for recovery efficiency.

Results

Demographic characteristics of sample.

Ninety-six families were recruited for participation in the study: 52 in Washington

County and 44 in Hood River County.

Whereas all of these families had at least one

adult who planned on working in agriculture

during that harvest season, 87 families had at

least one family member who had already

begun fieldwork at the time of recruitment.

The remaining 9 families had just arrived in

Oregon and were waiting for work to begin.

Forty-nine percent of the 96 families indicated that they came to Oregon directly

from Mexico, 34.4% came from California,

9.4% came from Washington, and 6.2%

came from other states. The majority indicated they lived ≤ 6 months in the previous

location, and 83.1% indicated they did some

type of agricultural work at their previous

location. The average number of moves the

families made in the last 12 months was 1.5

(SD = 1.1). The average family size was 4.8

persons (range = 3–10 persons). In these 96

families, 166 adults reported that they were

currently working in agriculture.

The mean age for the 166 adult migrant

agricultural workers was 30.1 years (SD =

7.1); the youngest worker was 19 years of age

and the oldest was 53 years of age (Table 1).

The workers in Hood River and Washington

Counties did not differ in their mean ages (p

= 0.23), but workers in Washington County

were 2.3 times more likely to be under 30

years of age than were workers in Hood River

County [odds ratio (OR) = 2.3, 95% confidence interval (CI), 1.21–4.27]. There were

94 (56.7%) males and 72 (43.4%) females

working in agriculture. There were no statistical differences in sex between the two locations (p = 0.54).

The education level of the 166 adults

ranged from 0 to 13 years, with a mean of

5.4 years (SD = 3.3). Adults in Washington

County (n = 97) had a mean education level

of 4.4 years (SD = 3.1) compared to a mean

of 6.8 (SD = 2.9) years for adults in Hood

River County (p < 0.001). Adults in Hood

River County spoke Spanish as their primary

language; however, 39 (43.3%) of the adults

from Washington County spoke indigenous

languages. Of the 39 who spoke indigenous

languages, 30 (76.9%) spoke Mixteco, 7

(17.9%) spoke Trique, and 2 (5.1%) spoke

Kanjobal. Only 26 adults in the total sample

indicated that they spoke English as a second

language.

Agricultural work practices. The majority

(79.8%) of the 166 migrant farmworkers were

fieldworkers and 16.3% were packers (Table

2); 2 workers in Washington County were

pesticide applicators. Workers performed multiple job tasks because workers do many jobs

over a season and over a year. Workers in

Washington County primarily pick berry

crops (blackberries, blueberries, raspberries,

and strawberries), often different types, and

workers in Hood River County primarily

prune, thin, and pick orchard crops (apples,

cherries, peaches, and pears). Although 2

workers indicated that they were pesticide

applicators, 21 workers indicated that they

mixed or applied pesticides, herbicides, or

fungicides in their current jobs. There were no

statistical differences between workers who

mixed or applied pesticides and whether they

worked in Washington County or Hood

River County (p = 0.78). These individuals

were predominately male (95.2%) and all

spoke Spanish as their primary language.

Only 27 farmworkers (18.1%) indicated

that they wore some type of protective clothing for their job (Table 2). Protective clothing included a respirator, a bandanna over

mouth or nose, glasses or goggles, sun hat or

cap, and/or coveralls. Use of protective

clothing did not differ according to location

area (p = 0.45). When asked whether workers entered their homes with their work

clothes on, 109 of 144 indicated that they

did. Workers in Hood River County were

more likely to enter their homes while wearing their work clothes than workers in

Washington County (p = 0.001)

The majority (n = 98; 66.7%) of workers

changed out of their work clothes within 30

min of getting home. Workers in Washington

County were 2.6 times more likely to change

out of their work clothes within 30 min of

getting home than were workers in Hood

River County (OR = 2.6; 95% CI, 1.3–5.1).

Ninety-nine (61.5%) of the workers indicated that they removed their work shoes

before entering their homes. Workers in

Children’s Health • Work characteristics and pesticide exposures

Environmental Health Perspectives • VOLUME 109 | NUMBER 5 | May 2001 535

Table 1. Characteristics of the 166 adults who lived in the residences of the 96 migrant families recruited

from Washington and Hood River Counties. 

Washington Hood River Total

Characteristics (n = 97) (n = 69) (n = 166)

Age (mean ± SD) 29.5 ± 7.6 30.8 ± 6.4 30.1 ± 7.1

Sexa

Male 53 (54.6) 41 (59.4) 94 (56.7)

Female 44 (45.4) 28 (40.6) 72 (43.4)

Years of education (mean ± SD) 4.4 ± 3.1 6.8 ± 2.9 5.4 ± 3.3

Primary languagea

Spanish 51 (56.7) 65 (100) 116 (78.0)

Indigenous languages 39 (43.3) 0 39 (22.0)

aValues shown are number (%). 

Table 2. Agricultural work and home practices among 166 adult migrant farmworkers from Washington

and Hood River Counties.

Washington Hood River Total

Work practices (no. missing) (n = 97) (n = 69) (n = 166)

Job category (6)

Mix/formulator 0 (0.0) 1 (1.6) 1 (0.6)

Applicator 2 (2.1) 0 (0.0) 2 (1.3)

Packer 14 (14.6) 12 (19.1) 26 (16.3)

Fieldworker 77 (80.2) 48 (76.2) 125 (79.8)

Foreman 3 (3.1) 2 (3.2) 5 (3.0)

Mixes or formulates pesticides (1)

Yes 13 (13.4) 8 (11.9) 21 (12.8)

No 84 (86.6) 59 (88.1) 143 (87.2)

Wears protective clothing (16)

Any 14 (16.1) 13 (21.0) 27 (18.1)

None 73 (83.9) 49 (79.0) 122 (81.9)

Enters home with work clothing (22)

Yes 51 (64.6) 58 (89.2) 109 (75.7)

No 28 (35.4) 7 (10.8) 35 (24.3)

Changes work clothes when home (18)

< 30 min 66 (76.7) 32 (52.5) 98 (66.7)

≥ 30 min 20 (23.3) 27 (47.5) 49 (33.3)

Removes work shoes/boots before entering home (5)

Yes 70 (73.7) 29 (43.9) 99 (61.5)

No 25 (26.3) 37 (56.1) 62 (38.5)

Values shown are number (%).
Washington County were 3.6 times more

likely to remove their work shoes before

entering their homes than workers in Hood

River County (OR = 3.6, 95% CI = 1.8–7.0).

This difference could be attributable to the

differences in weather conditions in the two

counties: it rains often during harvesting in

Washington County in June, but it is much

dryer during orchard harvesting in Hood

River County in September. 

Twenty of the 21 workers who mixed or

applied pesticides responded to the question

about protective clothing: 14 of the 20

workers wore some type of protective clothing. Two workers indicated that their job

category was pesticide applicator. Both of

these workers reported that they wore coveralls; one wore both coveralls and a respirator.

Nine (45%) of the 21 workers who mixed or

applied pesticides reported that they entered

their homes with their work clothes on, 12

(66.7%) changed out of their work clothes

within 30 min of getting home, and 10

workers (47.6%) removed their work shoes

before entering their homes.

Farmworker housing characteristics. In

Washington County the 52 study families

lived in a variety of housing including large

labor camps, trailers, and apartments. Labor

camps tended to be in close proximity to agricultural fields, with 70% of the labor camps

within 30 m of agricultural fields or nurseries.

Eighty percent of the nonlabor camp residences were within 200–1,000 m of agricultural land. In the Hood River sample of 44

families, 70% of their residences were within

30 m of orchards. The areas in front of the

homes tended to be common areas, with the

majority (n = 70, 80.5%) being bare earth.

Families in Washington County were more

likely to have a bare common area in front of

their homes than families in Hood River

County. Very few families had grass and other

plants in front of their homes (n = 6, 6.2%).

Interviewers asked whether there was a floor

mat for residents to wipe their feet before

entering the house. Fifty-three (55.8%) of the

farmworker dwellings had a floor mat; families in Hood River County were more likely

to have a floor mat at the door of their homes

than families in Washington County. 

The majority (n = 90, 93.8%) of families

did not have air-conditioning in their

homes. Only five (5.2%) had a window air

conditioning unit. Ninety-four of the 96

families indicated that they left their doors

and windows open for ventilation. The

majority (n = 84, 87.5%) of respondents

indicated that they left the doors and windows open every day, and 5 (5.2%) indicated that they left doors and windows open

more than once per week.

Fifty-eight percent of the Hood River

County families and 48% of the Washington

County families had washing machines on

site. The remainder used public laundry facilities. We found only 6 families in Hood River

County that had no running water (13.7%).

In the Washington County sample, 21 of 52

families had no running water (40.4%). 

Residential use of pesticides. Only six

families indicated that they had a cat, dog, or

both. Only one family reported the use of

flea/tick shampoo or dip on a home pet and

the application of flea/tick shampoos, dips,

or powders inside their home.

Workers were asked whether they stored

or used pest-control products in their homes.

Thirty-four percent of the homes in Hood

River County and 31% of the Washington

County families reported that they stored

some type of pesticide in their homes.

Thirty-two (62.8%) of the Washington

County families reported using some form of

pesticide in their homes compared to the 30

(68.2%) of the Hood River families (p =

0.58). Products were stored in a variety of

locations, either inside or outside the home.

Some families had multiple products, which

were stored in multiple locations in the home

or in outside sheds. 

Household cleaning. The majority (n =

59, 67.8%) of families had carpeted floors in

their homes. The likelihood of having carpet

in the home did not differ between the two

agricultural areas (p = 0.30). Only 42.5% of

the families owned a vacuum cleaner. Thirtyeight (58.5%) reported they cleaned their carpeted floors with a vacuum and 19 (29.2%)

used a broom. The majority (n = 34, 59.6%)

indicated that they vacuumed or swept their

carpeted floors daily or several times per week.

Eighteen (31.6%) said they vacuumed their

floors less than once per week, and all 18 of

those were located in Washington County. 

Families were asked to describe how they

cleaned noncarpeted floors. Of the 65 families

who responded to this question, all indicated

that they cleaned their floors using either a

broom, mop, mop with cleaner, or some

combination of these. The majority (n = 38,

55.1%) of workers cleaned their noncarpeted

floors daily. Workers in Washington County

were more likely to clean their floors daily

than were workers in Hood River County.

Most families (n = 46, 61.3%) wiped down or

dusted permanent surfaces in their homes several times per week. The majority (n = 51,

65.4%) used a damp cloth to wipe surfaces.

Pesticide residue sampling. Dust samples

were collected from the residences of 24

families in Washington County and 25 families in Hood River County. These families

lived in cabins in which toilet and washing

facilities were located in communal areas

outside the residence, trailers with private

washing and toilet facilities, houses with private washing and toilet facilities, and apartments in generally more urban areas. Table 3

shows the comparison of the homes from

which dust samples were obtained in the two

communities. The sizes of the homes in the

two communities were comparable; however, the homes in Hood River County were

located closer to agricultural fields than the

homes in Washington County (p = 0.002).

The median distance to agricultural fields in

Washington County was 48 m compared to

15 m in the Hood River sample. There was

no difference in the mean number of persons

per residence (p = 0.16). The housing in

both communities was very crowded, with

less than 150 ft2/person. Families living in

cabins had an average of 74 ft2/person,

whereas those in other housing shared an

average of 157 ft2/person. The average

square footage of a cabin was approximately

45% smaller than noncabin housing. 

The pesticide residues that were detected

in the farmworker homes in the two communities were very dissimilar (Table 4). In

Washington County there were 9 detectable

residues of four distinct types; in Hood River

Children’s Health • McCauley et al.

536 VOLUME 109 | NUMBER 5 | May 2001 • Environmental Health Perspectives

Table 3. Comparison of the housing of farmworkers

in Washington and Hood River Counties.

Washington Hood River

Housing (n = 24) (n = 25)

Size (ft2) 670 ± 89 667 ± 39

Number of persons 6.4 ± 0.72 5.2 ± 0.33

ft2/person 117 ± 17 136 ± 10

Median distance to field (m)* 48 15

Range 9–920 3–305

*p = 0.002.

Table 4. Frequency of specific pesticide residues found in grower and farmworker homes.

Farmworker Grower

Washington Hood River Hood River

Pesticide (n = 24) (n = 25) (n = 24)

AZM 0 22 19

Captan 5 1 0

Carbaryl 2 0 0

DDT 1 1 0

DDE 0 1 0

Dursban 0 0 7

Malathion 0 0 3

Pentachlorophenol 1 0 0

Phosmet 0 0 7

Piperolyl butoxide 0 1 0
County there were 26 detectable residues of 5

distinct kinds. Three families in Hood River

County and 15 families in Washington

County had nondetectable levels of pesticide

residue in their home dust samples. The most

common pesticide found in Washington

County was Captan, a chloroalkyl thio fungicide used on both apple and berry crops

(Table 4). In Washington County it is applied

in April–June on strawberry crops; the reentry

time after application is 4 days. DDT was

found in one Washington County residence

and one Hood River residence, and DDE was

found in one Hood River residence. 

The organophosphate pesticide AZM was

detected in 22 of the 25 farmworker homes

sampled in Hood River County. All homes

were within 3–305 m of agricultural land,

and more than 70% of the families lived

within 30 m of an apple or pear orchard.

Growers from the region indicated that AZM

had not been sprayed on the orchards in the

Hood River area during the 30 days preceding our sampling. Figure 1 shows that when

the nondetectable dust samples (3 of the 25

samples taken) are not included in the analysis, the median AZM concentration decreased

by an estimated 18% when the distance from

the field doubled (p = 0.04). If the 3 nondetectable samples are incorporated into the

analysis by assigning one-half the MLOQ

(method limit of quantitation; 0.1 μg/g), the

association between the median AZM concentration and distance becomes statistically

insignificant (p = 0.32). 

There was a positive correlation between

the number of persons living in each farmworker home and the level of AZM home

residue detected. We estimated that the

median levels would increase by approximately 40% for each additional person living

in the house. There was a stronger correlation between home residue levels and the

number of persons in each house who specifically worked in agriculture. The median

concentration increased 170% for each additional person working in agriculture (p =

0.002), as shown in Figure 2. If nondetectable readings are included, concentrations increase 230% for each additional

person working in agriculture. We found no

significant correlation between home pesticide residue samples and housing type or

square footage of the home. We found no

significant correlations between family use of

pest control products and residues found in

the home. 

Comparative grower homes. We compared the data on dust residues from homes

of migrant farmworker families to home dust

samples of 24 grower families in Hood River

County that were collected as part of another

investigation. The samples from grower

homes were taken in the same time of the

year as the migrant farmworker samples, and

AZM had not been sprayed in the 30 days

preceding sample collection. Dust samples

were taken from the entry area and the children’s play area in each grower home.

Questionnaires (demographics, home pesticide inventory, agricultural work practices,

health concerns, child agricultural safety)

administered to the grower families were similar to those used with the migrant farmworker families. The pesticide residue levels

and characteristics of the grower homes were

compared to the migrant farmworker data.

The frequency and types of pesticide residues

found in the homes of growers are shown in

Table 4. AZM was the most common pesticide (found in 19 of 24 homes).

The mean square footage of the 24

grower homes in Hood River County was

2,286 ± 183 compared to 667 ± 39 ft2 in the

25 migrant farmworker homes (p < 0.001).

The number of persons residing in the homes

differed between the two types of housing

with 4.3 ± 0.2 persons/residence among

growers and 5.2 ± 0.3 persons/residence

among migrant farmworkers (p = 0.02).

There was 559 ± 55 ft2/person in grower

homes compared to 136 ± 10 ft2/person in

farmworker homes (p < 0.001). 

All grower homes were large enough to

designate a play area; however, homes of

migrant workers were typically small and

children played in open areas where people

often walked. Median levels of pesticides in

these open areas of farmworker housing were

comparable to those found in the entry area

of grower homes (1.45 ppm in farmworker

homes compared to 1.64 ppm in grower

homes). The levels in the open areas in farmworker homes (1.45 ppm) differed significantly from the levels in the play areas of the

grower homes (0.71 ppm, p = 0.02).

Discussion

The migrant farmworker community has

been understudied, and there are socioeconomic and cultural factors which suggest that

children of farmworkers are at a disproportionate risk for health effects from environmental exposures. Migrant farmworkers

provide a crucial labor source for U.S. agriculture. Data suggest that 6 of 10 seasonal agricultural workers reside with a spouse, child, or

parent while employed in farmwork (10,15).

We believe that the Latino families in this

study are representative of the larger pool of

migrant farmworker families in the United

States. Our study sample from Oregon closely

parallels the statistics of farmworker families

in California, where the median number of

children is two and the mean number of children is three. Most seasonal farmworkers in

California have completed 8 or fewer years of

formal education in the United States and/or

their native country (71%). Our study sample

had a mean of 5.7 years of education. Spanish

is the predominant language, with only

approximately 15% speaking English as a second language. Approximately 8% primarily

speak indigenous languages. These statistics

have important implications for the development of pesticide safety training and health

education programs.

Our findings suggest that much improvement is needed in the use of protective clothing and equipment for agricultural workers

and in the implementation of decontamination procedures when they return home. In a

recent report of farm workers in Yakima

Valley, Washington (16), about 25% of

workers reported that they did not use protective gear and about 50% did not promptly

remove and wash contaminated clothing

when they went home. No information was

provided for the background of the agricultural workers in the Washington State sample, but our results suggest a much greater

problem among the migrant population.

Only 18% of our sample reported wearing

any type of protective clothing or equipment,

and the large majority wear their work clothes

into their homes. Our study also demonstrated that workers have many misconceptions about proper protective gear, with some

workers believing that ineffective devices such

as bandanas will provide protection against

pesticide exposure. Only 63% of the farmworkers reported that they change out of their

work clothes within 30 min of getting home.

Only 61% remove their work shoes before

Children’s Health • Work characteristics and pesticide exposures

Environmental Health Perspectives • VOLUME 109 | NUMBER 5 | May 2001 537

10.0

5.0

1.0

0.5

AZM (ppm)

5 10 50 100

Distance (m)

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●

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10.0

5.0

1.0

0.5

AZM (ppm)

No. of persons working in agriculture

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12345

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Figure 1. AZM in home dust residues by distance

from agricultural fields. p = 0.04.

Figure 2. AZM in home dust residues by number

of agricultural workers in the home. p = 0.002.
entering their homes compared to 74% in the

Washington State sample (16). The differences between the protective practices could

be related to the nature of the work performed. About 30% of the Washington State

sample had direct contact applying, mixing,

or loading pesticides (16), whereas only 13%

of our sample reported these work activities.

As reported in the Washington survey (16),

the use of protection in individuals who have

direct contact applying, mixing, or loading

pesticides is higher than in the general farmworker population. 

Our findings suggest that it is difficult to

characterize pesticide exposure risks among

agricultural communities. There are marked

differences in farming communities, the

backgrounds of the workers, the types of

work that are done, types of crops, pesticides

used, and the characteristics of housing available to the workers. Due to the challenges of

studying migrant farm workers, most

in-depth pesticide research studies have

focused on other pesticide-exposed agricultural populations (17). We found that a

community-based research approach with

partners familiar with the migrant farmworker population greatly improved access

to this population. Although there are similarities in the potential pesticide exposures in

migrant workers versus more geographically

stable agricultural workers, such as proximity

of residences to agricultural fields and the

nature of work activities, differences do

emerge. We found few incidences of migrant

farmworkers having pets in their homes,

therefore resulting in less potential exposure

from that mechanism. But residential use of

pesticide products in housing did occur at a

frequency quite similar to that reported in the

nonmigratory Washington sample (29% in

the Washington sample compared to 32% in

our sample) (16). Of interest is that, in both

of these agricultural samples, residential use of

pesticides is much lower than that reported

for the general U.S. population (17).

The type of housing available for migrant

farmworker families varies, but the constant

factor is that the housing conditions are

crowded. In the 1995 report of the National

Advisory Council on Migrant Health (18),

the average number of rooms in a single family dwelling for a migrant farmworker family

is between 1 and 2.6, and the average dimension of rooms is approximately 10 ft × 12 ft

or 12 ft × 15 ft. Indoor running water in the

housing unit is available in only 64.8 % of

camps, and laundry facilities are generally

unavailable. We found very diverse types of

housing available for the migrant families

that we studied. 

Few studies have addressed the nature of

pesticide exposures in children of agricultural

workers, particularly children of migrant

farmworkers. Other investigators have

reported that children living in households

with pesticide applicators and in proximity to

pesticide-treated orchards experienced greater

OP pesticide exposures than children of families with no occupational connection to agriculture who reside farther from agricultural

spraying (19). A limitation of our study was

the small number of homes sampled and the

distribution of AZM residues in these homes.

Because of this small sample size, we have presented the results of analysis of the data both

including and excluding the nondetectable

samples. Although the association between

AZM and distance from the field appears to

be driven by a few extreme data points,

Cook’s distance (a diagnostic measure of

influence) does not suggest extreme influence

is being exerted by any subset of the data

(20). Overall, the trend noted between the

levels of AZM and the number of agricultural

workers in the home and the distance from

orchards merits further research. Studies are

needed to determine if the differences noted

in the pesticide dust residues in grower and

farmworker homes result in differences in levels of biomarkers of pesticides in the urine of

the children living in these homes.

Although most of the pesticide residues

we identified were consistent with the agricultural pesticides used in the area and present at

levels comparable to those found by others

(9), we also identified DDT, DDE, and pentachlorophenol residues in some samples. We

are not able to identify the origin of these pesticides in the samples, but their presence suggests that migrant workers and their children

may be exposed to a wider range of pesticidal

agents than might be expected based on current agricultural practices alone. Our findings

suggest that migrant farmworker homes show

considerable variability in pesticide residues

both between and within communities.

Levels of residues may be influenced by distance from fields and the number of agricultural workers in residence. The size of the

home and the number of occupants may

result in disproportionate exposure risk for

children of growers and migrant farmworkers. In studies of dust residues in agricultural

homes, samples are usually taken from the

entry area of the home and the area of most

common play activity by the children (8,9).

This protocol is difficult to replicate in most

migrant farmworker situations. The housing

density is so large and there are so few rooms

that a common play area cannot be designated. Observational studies are needed to

document the play activities and play areas of

migrant farmworker children. Furthermore,

more child care settings are needed to provide safe play areas for these migrant children. It is only through partnering with

community groups acting as advocates for

the migrant farmworker community and

through using culturally appropriate methods

that researchers can gain access to the lives of

this vulnerable and understudied population.

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538 VOLUME 109 | NUMBER 5 | May 2001 • Environmental Health Perspectives