Residential proximity to specific crops and adverse birth outcomes in The Netherlands

Abstract

Aim: To explore associations between residential proximity to specific crops where pesticides are applied and adverse birth outcomes using individual level exposure and birth outcomes data.Methods: We selected all singleton births that occurred between 01-01-2009 and 01-01-2014 from the Dutch birth registry. We further selected mothers older than 16 years living in non-urban areas and who had complete address history and changed addresses at most once during pregnancy (N=325,435). We estimated the area of specific crops (maize, winter wheat, summer barley, summer wheat, other cereals, potatoes (consumption and starch), beets, ornamental plants, vegetables, fruit and flower bulbs) within buffers of 50, 100, 250 and 500 meters around the residence of each mother for the pregnancy period. We used generalized linear models to investigate associations between these exposure proxies and gestational age, birth weight, low birth weight, small for gestational age, large for gestational age, still births/infant mortality and prematurity, adjusting for individual and area-level confounders. Results: Our analysis provided no clear evidence that living in proximity to crops increased risks of adverse birth outcomes. We noted that babies from mothers living near summer barley had on average a higher birth weight (β [95% CI] in gram/hectare of summer barley: 50m buffer 327.7 [88.7, 566.6], 100m buffer 52.2 [5.9, 98.5], 250m buffer 0.9 [-6.4, 8.2], 500m buffer -0.2 [-1.7, 1.3]) and a greater chance of being large for gestational age (OR [95% CI] in the same buffers 16.3 [3.8, 70.2], 1.6 [1.2, 2.2], 1.0 [0.96, 1.08], 0.99 [0.98, 1.0]), although these results were not statistically significant after correction for multiple testing. Conclusions: Residential proximity to crops was not associated with adverse birth outcomes. However, the finding that babies of mothers living near summer barley crops tend to be larger should be further explored.