Maternal-Child Exposures to Persistent Organic Pollutants in Dhaka, Bangladesh

Michael Leung,Daniel E Roth,Therese Haugdahl Nøst,Dorte Herzke,Abdullah Al Mahmud,Eszter Papp,Frank Wania

doi:10.1007/s12403-018-0286-x

Abstract

Information about the human burdens of persistent organic pollutants (POPs) in low- and middle-income countries is limited. In particular, studies often include only a small subset of POPs. To address this data gap, we aimed to assess maternal-child exposures to POPs in Dhaka, Bangladesh. We quantified 16 organochlorine pesticides, 12 polychlorinated biphenyls, 21 brominated flame retardants, 18 per- and polyfluorinated alkyl substances, 2 polycyclic aromatic hydrocarbons, and short-chain chlorinated paraffins in 18 pooled samples of human cord blood from 90 mother–infant pairs living in Dhaka, Bangladesh (2014–2015). In all pooled samples, we detected high levels of p,p′-DDT (median 81.6 ng/g lipid) and its metabolites p,p′-DDE and p,p′-DDD (median 551 and 10.7 ng/g lipid, respectively), where the p,p′-DDE/p,p′-DDT ratio ranged from 2.9 to 9.8 indicating recent dichlorodiphenyltrichloroethane (DDT) exposure. We also detected acenaphthene, decabromodiphenyl ethane, o,p′-DDT, o,p′-DDE, hexachlorobenzene, β-hexachlorocyclohexane, hexabromobenzene, and perfluorooctanoic acid in a subset of samples. For the other 59 target compounds, concentrations were below the limits of detection, despite using ultra-trace analytical methodology. No trends were observed when stratifying the analyses of detected POP concentrations by maternal age, maternal body mass index, or large fish consumption. These findings highlight recent DDT exposure in Dhaka, but the overall POP burden was otherwise low in this sample of pregnant women/newborns. Future monitoring efforts should focus on newly detected POPs for which burdens may be increasing due to ongoing industrialization in Bangladesh.

Highlights

Persistent organic pollutants (POPs) are a broad class of synthetic chemicals developed for industrial, agricultural, and/ or commercial applications that have known or suspected human toxicity, based on a growing body of animal and epidemiological studies
These measures have led to declining human concentrations of many persistent organic pollutants (POPs) in many high-income countries (Kong et al 2014), there is scant knowledge of the human burden of exposures in low- and middle-income countries (LMICs), where heavy industrialization and permissive environmental regulations are widespread today
Most epidemiologic studies have focused on ‘legacy POPs’ including the polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT), whereas other pollutant groups have not been evaluated in terms of exposure patterns or associations with disease outcomes (World Health Organization 2012), with a notable lack of data from LMICs

Summary

Introduction

2015; Diamanti-Kandarakis et al 2009; Elobeid and Allison 2008; Grant et al 2014; Liu and Peterson 2015; Loomis et al 2015; Newbold et al 2008; Schug et al 2011; TangPéronard et al 2011) They can last for years before degrading into less dangerous forms, travel long distances (e.g., through air, water, exported food, commercial products), and bioaccumulate in higher-order animals present in many diets, such as fish which tend to enrich POPs in their tissues (Geyer et al 2000; United Nations Environmental Programme 2005). Most epidemiologic studies have focused on ‘legacy POPs’ including the polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT), whereas other pollutant groups have not been evaluated in terms of exposure patterns or associations with disease outcomes (World Health Organization 2012), with a notable lack of data from LMICs

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Results