Serum concentrations of perfluoroalkyl and polyfuoroalkyl substances and determinants in men of childbearing age

Background Perfluoroalkyl and polyfluoroalkyl substances (PFASs) exposure may affect male reproductive health. There are regional differences in PFASs exposure levels among men of childbearing age in China, and current research results on associated influencing factors are inconsistent.

Objective To investigate the levels of PFASs in serum and their determinants among men of childbearing age.

Methods The participants (n=113, 22-45 years old) were from a cross-sectional study of exposure to environmental pollutants and male reproductive health damage in Hubei Province conducted from April to June 2013 at the Reproductive Medicine Center of Tongji Hospital, Wuhan, Hubei Province. Eleven kinds of PFASs were measured in serum by isotopic dilution-high performance liquid chromatography-tandem mass spectrometry. The included PFASs were prefluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS). Information about participants' demographic characteristics, lifestyle, and habits was collected by a set of self-designed questionnaires. The associations of demographic characteristics, lifestyle, and habits with exposure to PFASs were analyzed by linear regression.

Results The major components of PFASs were PFOS and PFOA, and the concentrations expressed as M (P₂₅, P₇₅) were 8.31 (4.90, 17.79) ng·mL⁻¹ and 2.77 (2.18, 3.46) ng·mL⁻¹, respectively. The positive rates of six PFASs (PFOA, PFNA, PFDA, PFUdA, PFHxS, and PFOS) were 100%, followed by PFDoA and PFTrDA (87.61% and 88.59%, respectively). The linear regression results showed that age was positively associated with the levels of Σ₈PFASs (sum of the concentrations of the eight PFASs with a positive rate greater than 80%) (P < 0.05). The concentration of serum PFOA in men with monthly family income of 2000-4000 yuan was 53.73% (P < 0.01) higher than those in men with monthly family income of <2000 yuan. The serum concentrations of PFNA and PFTrDA were both 32.31% (P < 0.05) higher in men with monthly family income ≥4000 yuan than those in men with monthly family income <2000 yuan. The serum concentration of PFHxS in men who used plastic cups was 33.64% (P < 0.01) higher than that in men who did not report oral contact with plastic products (plastic tableware, plastic cups, and plastic bags for packing food). The serum concentrations of PFHxS, PFOS, and Σ₈PFASs were 33.64% (P < 0.01), 43.33% (P < 0.01), and 36.34% (P < 0.05) higher in men who bathed with laundry soap than those in men who did not use detergents. Men who bathed with toilet soap had a 34.99% (P < 0.05) higher serum concentration of PFHxS than those who bathed without detergents.

Conclusion Men of childbearing age are exposed to PFASs extensively. Age, monthly household income, usage of laundry soap or toilet soap in bathing, and usage of plastic cups may influence the level of PFASs in serum. However, further investigation is needed to confirm these results.