Oregon Health & Science University Oregon Child Development Coalition Assessment of Exposure to Organophosphate Pesticides in Migrant Farm Workers and Their Children Linda McCauley, Rachelle Mann-Gaytan, William Lambert, Juan Muniz, Michael Lasarev & Caren Ebbert Oregon Health & Science University Oregon Child Development Coalition Presented by Rachelle Mann-Gaytan

Migrant Farm Workers

Purpose of this analysis To characterize the extent of exposure to organophosphate (OP) pesticides for children of migrant farm workers To identify factors influencing residential levels of these pesticides To compare the level of exposure in farm worker families with a reference group of grower families

Methods With the Oregon Child Development Coalition (OCDC), we recruited families through the Migrant HeadStart Program and the growers association OCDC and OHSU teams conducted interviews and collected environmental samples in homes in summers of 1998 and 1999 Carpets were sampled with HSV3 vacuum Pesticide residues were analyzed by GC/MS Urinary metabolites were analyzed by GC with flame photometric detection

Results of Floor Dust Samples Azinphos methyl (AZM) was found in carpet dust from 22 of 25 farm worker homes Few other pesticides detected Median = 1.45 ppm (range 0.3 – 12.0) AZM levels decreased with greater distance from the orchards AZM levels increased with number of household members working in agriculture

Floor Dust AZM Levels by Distance to Orchard 10.0 p-value = 0.04 5.0 o o Azinphos Methyl (ppm) o o o o o o o o o o o o 1.0 o o o o o 0.5 o o 5 10 50 100 Meters

Home AZM Levels by Number of Workers in Household 10.0 p-value = 0.002 5.0 o o Azinphos Methyl (ppm) o o o o o o o o o o o o 1.0 o o o o o 0.5 o o 1 2 3 4 5 Number of persons working in agriculture

Differences in Homes of Workers and Owners

AZM in Floor Dust of Worker and Owner Homes Max 75% Median 25% Min

Characteristics of Households Farm Workers n = 25 Farm Owners n = 24 Area of home (m2)** 62 (+3.6) 212 (+17.0) Number of persons* 5.2 (+0.3) 4.3 (+0.2) Area per person (m2/person)** 12.6 (+0.9) 51.9 (+5.1) * p = 0.02 ** p < 0.001

Other factors influence indoor levels Lower indoor AZM levels were observed when male farm workers or owners reported that they: Removed shoes before entering home Changed out of work clothes before entering home Changed out of work clothes within 30 minutes after arriving home Washed up within 30 minutes of arriving home

Workers: Do you take off your boots before entering your home? Response (n) AZM (ppm) Range Median Mean Never (5) 0.30-13.40 6.90 6.72 Sometimes (1) 3.20 --- Yes (7) 0.01-15.50 1.00 4.10 p = 0.27, Wilcoxon rank sum test

Owners: Do you take off your boots before entering your home? Response (n) AZM (ppm) Range Median Mean Never (1) 7.34 --- Sometimes (13) 0.03-5.90 0.37 1.10 Yes (10) 0.03-6.52 0.89 1.56 p = 0.28, Wilcoxon rank sum test

Urinary Metabolites in Adults Max 75% Median 25% Min

Urinary metabolite concentrations in younger vs. older children 250 0 – 6 years old 200 150 Median DMTP  g/ g Cr 100 7 – 11 years old 50 F M A M J J A S O Month

Urinary metabolite concentrations in adult thinners vs. non-thinners 150 Thinners 100 Median DMTP  g/ g Cr Non-thinners 50 F M A M J J A S O Month

Urinary metabolites in children of migrant farm workers

Implications Dissemination of video to educate farm workers on practical ways to reduce exposures for their children “Deep cleaning” of homes to remove accumulated dust and pesticide residues

Acknowledgments This research is supported by a grant from the National Institute of Environmental Health Sciences (RO1 ES08707)