Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB)

摘要

BACKGROUND : Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane)and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDTfor malaria control with the aim of identifying exposure-reduction strategies.METHODS : The present analysis included 381 women enrolled in the Study of Women and Babies(SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, SouthAfrica. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regardingvarious demographic and medical factors were administered and blood samples were obtained. Weclassified the women into three exposure groups by type of residence: unsprayed village (n = 175),IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106),IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). Weused multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter)and DDE (in micrograms per liter) to identify predictors for each group.RESULTS : Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartilerange (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT andDDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0),respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap,had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. InDDT IRS households, women who reported taking more than six actions to prepare their homebefore IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) thanwomen who took fewer than four actions.CONCLUSION : The predictors of DDT and DDE plasma levels identified in the present study mayinform interventions aimed at decreasing exposure. Among households where DDT is likely to beused for IRS, education regarding home preparations may provide an interventional target.