Increased levels of persistent organic pollutants in serum one year after a great weight loss in humans: Are the levels exceeding health based guideline values?

Abstract

Background: With the growing prevalence of obesity, an increased number of bariatric surgeries are being performed. Lipophilic persistent organic pollutants (POPs) are stored in adipose tissue, and an increased release of lipophilic POPs into the blood circulation may occur following rapid weight loss such as after bariatric surgery.

Objectives: To evaluate and compare POP levels in serum before and after bariatric surgery, and to assess if the POP levels exceeded health based guideline values, with particular focus on women of childbearing age (WCBA).

Methods: Serum samples from 63 patients before and one year after bariatric surgery were analysed for organochlorine pesticides (OCPs); polychlorinated biphenyls (PCBs); and brominated flame retardants (BFRs).

Results: Mean weight loss one year after surgery was 32.1kg. The levels of all the analysed POPs in serum increased during the study period. Median levels of dichlorodiphenyldichloroethylene (p,p'-DDE), hexachlorobenzen (HCB) and PCB-153 increased from 90.2ng/g lipid weight (lw) to 158.5ng/glw, from 21.1ng/glw to 36.4ng/glw and from 48.7ng/glw to 71.5ng/glw, respectively. The highest percentage increase was observed for PCB -138, with 83.1%. BFRs were detected in low sample numbers and at low levels. Guideline values for ΣPCB₆ in serum were exceeded for 5% of the participants.

Conclusions: Weight loss after bariatric surgery resulted in increases of POPs levels in serum between 46.7%-83.1%. Guideline values for ΣPCB₆ in serum were exceeded for 5% of the participants. For WCBA, the possible transfer of comparable levels to infants warrants further attention.

Keywords: Bariatric surgery; Breast milk; Estimated daily intake; Increased blood levels of POPs; Obesity; Persistent organic pollutants (POPs).