WHO/UNEP global surveys of PCDDs, PCDFs, PCBs and DDTs in human milk and benefit–risk evaluation of breastfeeding

Abstract

Since 1987, the World Health Organization (WHO) carried out global surveys on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in human milk. This study presents a review of the three most recent surveys from 2000 to 2010, including DDT. The objective was to identify global quantitative differences and provide baseline information for 52 countries or provide time-trends for countries with previous data. Individual human milk samples were collected following a WHO-designed procedure and combined to form a national pooled sample. Here, we report global levels for PCDDs, PCDFs, PCBs and the sum of o,p′-DDT, p,p′-DDT, o,p′-DDE, p,p′-DDE, o,p′-DDD and p,p′-DDD (ΣDDTs). A concise risk–benefit evaluation related to human milk contamination with these persistent organic pollutants (POPs) was also done. Large global and regional differences were observed. Levels of PCDDs and PCDFs were highest in India and some European and African countries. PCB levels were highest in East and West Europe. The highest levels of ΣDDTs were found in less industrialized countries. A temporal downward trend for PCDDs, PCDFs and PCBs is indicated. A risk–benefit assessment indicates that human milk levels of PCDDs, PCDFs and PCBs are still significantly above those considered toxicologically safe, while ΣDDTs are below or around those considered safe. With respect to potential adverse health effects, a more dominant role of in utero exposure versus lactational exposure is indicated. If potential adverse effects are balanced against positive health aspects for (breastfed) infants, the advantages of breastfeeding far outweigh the possible disadvantages. Our observations provide a strong argument to plea for further global source-directed measures to reduce human exposure further to dioxin-like compounds.

Who in the world is most exposed to polychlorinated biphenyls? Using models to identify highly exposed populations

“…In other words, source proximity and long-range transport need to be taken into account in addition to dietary habits when comparing the exposure of different human sub-populations to persistent organic pollutants. A worldwide survey of concentrations in human breast milk [23] identifies exclusively central and Eastern European countries as having elevated PCB concentrations, consistent with the intensity of PCB emissions in this region (figure 1). Concentrations in breast milk in countries in tropical latitudes and the Southern hemispheric are generally much lower, again reflective of the global distribution of historical PCB emissions.…”

Factors Associated with Maternal Serum Levels of Perfluoroalkyl Substances and Organochlorines: A Descriptive Study of Parous Women in Norway and Sweden

“…This is explained by excretion of OCs in the breast milk, resulting in lower maternal serum levels of OCs and exposure to breastfeeding children [51]. A recent review concluded that the benefits of breastfeeding far outweigh the potential disadvantages, but argues to plea for further global source-directed methods to reduce human exposure to OCs [52]. …”

Longitudinal assessment of mycotoxin co-exposures in exclusively breastfed infants

“…For example, other environmental contaminants frequently measured and detected in breast milk include dioxins, polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFAS). Their concentration in European breast milk was reported up to 376 ng/L and 114 ng/kg for perfluorootanoic acid (PFOS) and WHO toxicity equivalent levels for dioxin-like compounds, respectively (Anderson et al 2019;Antignac et al 2016;Cariou et al 2015;van den Berg et al 2017). In contrast to these reports, our experiment highlights the low abundance of mycotoxins in breast milk.…”