Persistent organic pollutants and heavy metals in adipose tissues of patients with uterine leiomyomas and the association of these pollutants with seafood diet, BMI, and age

Background, aim, and scope: Persistent organic pollutants and heavy metals can cause diseases in women, however, the relationships of these pollutants and uterine leiomyomas (UL), which are non-cancerous tumors of the uterus, are unclear. This study focused on the quantification of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and heavy metals in subcutaneous and visceral fat obtained from patients with UL and in subcutaneous fat of a control group of women without UL to determine if there were any correlations between concentrations of persistent organic pollutants (POPs) and heavy metals and the incidence of UL. Materials and methods: Samples were collected from ethnic Chinese residents from six hospitals and six cosmetic surgery clinics in Hong Kong. Patients with UL provided both subcutaneous and visceral fat, while women without UL (control group) provided subcutaneous fat through liposuction. Analyses of POPs and heavy metals were conducted using gas chromatography-mass spectrometry and inductively coupled plasma-optical emission spectrometry, respectively. Total mercury (Hg) content was measured using an atomic fluorescence spectrometer. Results: Significantly higher (p<0.01 or 0.05) concentrations of dichlorodiphenyltrichloroethane (DDTs), hexachlorocyclohexane (HCHs), PCBs, PAHs, PBDEs, arsenic (As), cadmium (Cd), lead (Pb), and Hg were detected in the subcutaneous fat of patients when compared with those of the control group. Significant correlations were found between pollutant concentrations of subcutaneous and visceral fat in the patient group, with visceral fat containing significantly higher (p<0.01 or 0.05) concentrations of As (subcutaneous fat: 0.59 μg/kg fat; visceral fat: 0.73), Cd (0.38; 0.47), Pb (5.24; 5.98), and Hg (9.12; 13.3). Discussion: Since UL has a close relationship with estrogen levels in women, and OCPs, PCBs, PAHs, and PBDEs have an estrogen-like effect, these chemicals may correlate with UL. This study showed higher levels of DDT and its metabolites, HCHs, fluoranthene, pyrene, benzo(a)pyrene, PCBs, and BDE-99 in patients with UL than those in the control group. Furthermore, higher concentrations of Cd, Pb, As, and Hg were found in the patient group than those in the control group suggesting that these chemicals may correlate with UL. Conclusion: Our studies demonstrated that these persistent organic pollutants and some heavy metals may have correlations with UL, and their accumulation in the body is positively correlated with seafood diet habit, body mass index, and age. In the patient group, higher levels of persistent organic pollutants and some heavy metals were found in visceral fat than in subcutaneous fat confirming the long-held belief that visceral fat is more pernicious and pathogenic than subcutaneous fat. Recommendations and perspectives: It is recommended that women minimize their exposure to environmental pollutants as much as possible which includes consuming certain seafoods in moderation, such as fatty fish, carnivorous fish (tuna and swordfish), and shellfish which are known to concentrate POPs and heavy metals, respectively.