Statistical techniques applied to environmental health sciences

National Institute Of Environmental Health Sciences

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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. In light of the growing evidence that suggests that pesticide use contributes to respiratory symptoms, we have used data from the AHS to evaluate the association of 79 currently used pesticides with two types of wheeze: allergic wheeze and non-allergic wheeze. Allergic wheeze required self-report of one or more episodes of wheeze during the past year plus history of doctor-diagnosed hay fever; non-allergic wheeze required the wheeze symptom but without history of hay fever. We used polytomous logistic regression to compare those with each of the two types of wheeze to controls (those without wheeze symptoms). Of the 79 pesticides studied, with exposure assessed dichotomously (current use or not), 20 were associated with non-allergic wheeze (18 positively, 2 negatively) and 17 were associated with allergic wheeze (16 positively, 1 negatively) with ten pesticides common to both types of wheeze. (collaboration with Jane Hoppin, formerly EB, currently NCSU.) Using a data from the Agricultural Lung Health Study (a sub-study of the AHS), we have examined associations of house dust endotoxin levels with adult asthma (manuscript submitted). We have also submitted a manuscript investigating the relationship of early life farm exposures to adult asthma and atopy. Work on other aspects of the epidemiology of respiratory symptoms and disease in relationship to farming exposures is continuing. (see also Z01 ES102385; PI Stephanie London, EB.) Recently, using data from the SELF study, we have reported an association between having been fed soy formula as an infant and heavy menstrual bleeding as an adult. We also reported an association between the use of estrogen-containing contraception and increased serum 25-hydroxy vitamin D levels. (see also Z01 ES049013; PI Donna Baird, EB.)