1. Agricultural pesticide exposures and risk of childhood cancers I4C Meeting Barcelona September 19-20, 2011

2.  Lead investigators: Mary Ward and Leslie Stayner  Co-investigators: Martine Vrijheid CREAL Gabriella Tikellis, MCRI Martha Linet, NCI Kurt Straif, IARC Mike Dellarco, NICHD/NCS

3. 1. To evaluate risk of childhood cancers in relation to residential proximity to agriculture during pregnancy and early life 2. To determine pesticide use around the birth residence and the association with childhood cancers … accounting for parental occupational exposure..

4. Most studies of childhood cancers (leukemia, lymphoma, brain cancer) observed increased risk associated with parental occupational pesticides Meta-analyses of leukemia point to maternal occupational exposure and residential exposure during pregnancy as being most important For occupational exposure, farm-related pesticides showed somewhat stronger risks than other occupational pesticides

5. Residential proximity to agricultural pesticides associated with elevated rates in some but not all studies One case-control study evaluated proximity No cohort studies Exposure studies indicate that distances of up to 1000 meters and time periods up to 2 years may be important in predicting levels in homes

6. GIS-based methods in the Midwest U.S. Increasing acres of crops within 750 m of homes increased herbicide concentrations Ward et al, 2006 resres

7. Satellite imagery used for crop maps  1998-2000 Dust samples 11 agricultural herbicides GPS measurements

9. Buffer (meters) All residencesWithin towns 10029%18% 25044%38% 50060%52%

10. Crop maps  Time of interview  Historical maps Pesticide Use Reporting database  Since 1990  Section ~1 sq. mile

11. 7 agricultural pesticides, use in prior 2 years, 500 & 1250 meters Metrics were correlated with dust concentrations for 5 of 7 pesticides  rank correlations 0.33-0.51 Strongest associations pesticide use within 1250 meters & 365-750 days Gunier et al. 2011

12. Case-cohort study, 10 controls/case Cohorts with birth addresses for geocoding Land cover maps and crop-specific pesticide use data will be obtained from each country for birth year Adjust for parental occupational pesticide exposure

13.  Geocoding of birth addresses – centrally or by each cohort?  May need to create crop maps for some areas/years  Sample size currently available

14. CohortLive Births Birth-yearsTotal cancers ALL cases ALSPAC 140621991-1992243 TIHS 106281987-1995313 JPS 924081964-197612540 CPP 580001960-19654812 MoBa 1084871999-2007?~44** DNBC 968401996-2002200** 41** total 380425228102