Statistical techniques applied to environmental health sciences

National Institute Of Environmental Health Sciences

Investigators

Linked publications, trials & patents

Abstract

We have recently guided the data analysis for several projects, primarily involving data from the Agricultural Health Study (AHS), a cohort of licensed pesticide applicators (mostly farmers) from Iowa and North Carolina, including a sub-study of the AHS, the Agricultural Lung Health Study (ALHS). (See ES049030, Dale Sandler PI, for AHS; ES102385, Stephanie London PI, for ALHS). Using data from the AHS, following an earlier suggestion in the literature, we examined whether use of permethrin or other pyrethroid pesticides was associated with all-cause mortality as well as with mortality from specific causes. We found no clear evidence that use of those pesticides was associated with mortality in the AHS cohort. In another study, we evaluated whether a variety of farming-related exposures including working with hay, animals, or pesticides was associated with wheeze among women in the AHS. We found that use of glyphosate and working with moldy hay were each associated with both allergic and non-allergic wheeze and that three other specific pesticides were associated with at least one wheeze sub-type. Within the ALHS, we investigated possible interactions between genetic risk scores for impaired pulmonary function and smoking, asthma, and endotoxin. Although we found no interaction of genetic risk scores with endotoxin exposure, associations with genetic risk scores were stronger for current or former smokers than non-smokers and stronger for asthmatics than non-asthmatics. We recently examined whether early-life farm exposures were associated with reduced risk for self-reported childhood eczema or atopic dermatitis. Though we found no association with eczema overall, several early-life exposures were associated with reduced risk for having both atopy and eczema. Also using data from the ALHS, we evaluated the association of residential wood burning with pulmonary function. We found that wood burning was associated with lower pulmonary function among individuals with asthma but not among those without asthma. In collaboration with colleagues from the US EPA, we studied blood lead levels in children residing in an area with soil contaminated by a previously operating lead smelter and asked whether those levels were reduced after soil remediation. Residential and neighborhood soil lead levels were associated with blood lead levels in these children before remediation but only neighborhood soil lead level remained associated after remediation.