Fat under the skin points to chemical exposure
Study of POPs in obese patients
11.06.2013 |Chemical Watch
A Belgian study has identified a wide range of persistent organic pollutants (POPs) in human adipose (fat) tissues. The work suggests that fat collected from just beneath the skin can be used to monitor exposure to environmental chemicals such as POPs.
POPs have a tendency to accumulate in fat and some studies have linked them to obesogenic effects. Earlier his year, a group of scientists, including Linda Birnbaun, director of the National Institute of Environmental Health, published a review paper emphasising the role of human adipose tissue in toxicological responses to POPs (CW 7 February 2013).
A team from Antwerp University collected adipose samples from over 50 obese patients admitted to hospital for gastric bypass surgery and tested for a wide range of organohalogenated POPs in subcutaneous ¬fat – from just beneath the skin – and deeper visceral fat, which is more pathogenic in adult-onset diabetes, heart disease and cancers.
All of the samples contained organohalogenated compounds. “PCBs [polychlorinated biphenyls] and DDTs [dichlorodiphenyltrichloroethane and its metabolites] were the major POPs in all fat samples, and this is a rather common profile in the Belgian population,” said lead author, Adrian Covaci, from the university’s toxicological centre. Nevertheless, levels of the PCBs were lower than those identified in previous Belgian studies, matching falling levels in the environment.
Levels of polybrominated diphenyl ether (PBDE) flame retardants were similar to those identified in other European and Japanese adipose studies but “considerably lower” than in US samples, said professor Covaci. The team investigated the relationship between POP levels in adipose tissue and body weight and shape and found a significant positive correlation between levels of highly chlorinated PCBs and PBDEs and waist measurements and/or waist to hip ratios.
Importantly, levels and patterns of POP distributions were similar in the visceral and subcutaneous fat. Hence, “subcutaneous fat could be used as an indicator for monitoring human exposure to environmental chemicals, mostly the persistent organic pollutants,” said professor Covaci. The subcutaneous fat is far easier to sample than the visceral.
The Belgian team is currently studying human exposure to endocrine-disrupting chemicals (EDCs), including some POPs. “We have recently begun investigating the occurrence of EDCs in human visceral and subcutaneous fat, serum and urine from Belgian obese patients,” said professor Covaci. “We are also establishing new knowledge regarding the patterns and relationships between EDCs and various markers of obesity.”
The study is published in Environment International.
(from Chemical Watch)