The EARTH Study was designed to examine exposures across several windows: paternal and maternal preconception windows, and maternal periconception and prenatal windows. We obtain prospective repeated urine and blood samples at several times during these periods (Figure 1). There is also an optional voluntary hair sample collection. All samples were collected using methods to minimize exogenous contamination by known environmental chemicals (Calafat, et al., 2015 (link)). To date, we have collected 32,792 and 8,967 urine aliquots, and 8,156 and 3,875 blood aliquots from women and men, respectively. These have been archived and stored at the Harvard T.H. Chan School of Public Health. The CDC has quantified urinary biomarkers of >40 chemicals, including: phthalates and diisononyl cyclohexane-1,2-dicarboxylate (DINCH) metabolites, phenols (e.g., bisphenol A, triclosan, parabens), and pesticides (metabolites of organophosphates, pyrethroids, 2,4-dichlorophenoxyacetic acid, and N,N-diethyl-m-toluamide). Organophosphate flame-retardants and polybrominated diphenyl ethers were measured at Duke University.
In whole blood, we have quantified heavy metals and metalloids (e.g., lead, cadmium, manganese) at the Mount Sinai School of Medicine in a subgroup of 150 women. We have measured serum folate, vitamin B12, fatty acids, and vitamin D concentrations among 100 women. Among 558 women, we have also analyzed serum for thyroid hormones (thyroid stimulating hormone, free thyroxine 4 (T4), T4, free T3, T3, thyroglobulin, and thyroperoxidase antibodies). To date, we have quantified mercury in more than 1,200 hair samples. We have also analyzed more than 1200 semen samples for standard semen quality parameters. From participants undergoing oocyte retrieval, we have stored 6,041 follicular fluid aliquots and we have analyzed 147 of them from 143 women for phthalate metabolites and phenols. In small pilot studies, we have measured non-coding micro RNAs in semen, and obtained and archived amniotic fluid samples.