We used the annual reports from the USDA PDP to classify fruits and vegetables
according to their average pesticide residue status in the US food
supply (US Department of Agriculture, 2006–2012). The PDP reports
included data on pesticide residues for 35 of the 38 fruit and vegetable
items included on the FFQ; data on pesticide residues for apricots, Brussels
sprouts and mixed vegetables, which accounted for4%of total fruit and vegetable
intake, were unavailable, thereby excluding these foods from the pesticide
classification.We considered three measures from the PDP to classify
fruits and vegetables: (i) the percentage of samples tested with any detectable
pesticides; (ii) the percentage of samples tested with pesticides exceeding the
tolerance level and (iii) the percentage of samples with three or more types of
detectable pesticides.TheUSDAdoes not sample every food every year, and
therefore data were collected and averaged by annual reports from 2006 to
2012. When a FFQ item combined more than one food for which the PDP
reported data separately (e.g. eggplant and summer squash) we used the
weighted average of pesticide residue according to the ratio of consumption
of each produce fromtheUSDAreports (Gebhardt et al., 2008). Next, foods
were categorized according to tertiles for each of the three measurements of
contamination and assigned a score of 0 to each fruit and vegetable in the
bottom tertile, 1 to fruits and vegetables in the middle tertile and 2 for
fruits and vegetables in the top tertile. Scores for each fruit and vegetable
were then summed across the three contamination measures. Fruits and
vegetables with a total score ≥4 (