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Background Per- and polyfuoroalkyl substances (PFAS) are categorized as persistent organic pollutants and commonly detected in humans, and their toxicity has attracted widespread attention. However, few studies have reported comparison of PFAS levels and potential factors between women pregnant using assisted reproduction technology (ART) and women pregnant naturally. Objective To analyze and compare serum concentrations and sociodemographic determinants of PFAS in pregnant women conceiving through ART and conceiving naturally from Shanghai. Methods Based on the China National Birth Cohort (CNBC) in Shanghai from 2017 to 2019, 333 pregnant women conceiving through ART and 689 pregnant women conceiving naturally were recruited during the same period as study subjects. The concentrations of 32 PFAS were measured in early-pregnancy serum of all pregnant women, and four PFAS with the highest co-exposure levels in both groups were included in the subsequent analysis. Multiple linear regression models were performed to evaluate the associations of sociodemographic factors with serum PFAS concentrations in the two groups respectively. Beta coefficients and 95% confidence intervals (CI) were exponentiated to calculate the ratio of the geometric mean (GM) of PFAS concentrations after each unit change in the independent variable. Results Perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), 6∶2 chlorinated polyfluoroethersulfonic acid (6∶2 Cl-PFESA), and perfluorohexanesulfonic acid (PFHxS) were four major PFAS in serum of pregnant women conceiving through ART and conceiving naturally, and the concentrations of PFOA, PFOS, and 6∶2 Cl-PFESA were higher in pregnant women conceiving through ART than in pregnant women conceiving naturally (P <0.05). The results of multiple linear regression analysis showed that age at pregnancy and household income were associated with serum PFAS levels in both groups. The serum concentrations of PFOS were higher in pregnant women aged ≥35 years old who conceiving through ART (GM ratio=1.26, 95%CI: 1.04, 1.54) and conceiving naturally (GM ratio=1.24, 95%CI: 1.08, 1.42) than pregnant women aged <30 years old respectively. Pregnant women conceiving through ART and conceiving naturally whose household annual income >300000 CNY had lower serum concentrations of PFOA [GM ratio (95%CI): 0.82 (0.72, 0.95) and 0.89 (0.81, 0.97), respectively] and PFHxS [GM ratio (95%CI): 0.66 (0.51, 0.86) and 0.77 (0.66, 0.90), respectively] than those women whose household annual income <200000 CNY. Additionally, pregnant women conceiving naturally with a graduate education or above had lower serum 6∶2 Cl-PFESA concentrations than women with an education below college (GM ratio: 0.81), and multiparous pregnant women conceiving naturally had higher serum concentrations of PFOS, 6∶2 Cl-PFESA, and PFHxS than primiparous pregnant women (GM ratio: 1.14, 1.25, and 1.27 respectively). Conclusion Although differences in serum PFAS levels are found between pregnant women conceiving through ART and women conceiving naturally in this study, maternal age and household income are common determinants of PFAS exposure levels in both populations. We find no special sociodemographic factors to affect PFAS concentrations of pregnant women conceiving through ART compared to pregnant women conceiving naturally. Further research is required to explore other potential factors.
RESUMEN
Background Neonicotinoid insecticides (NEOs) are emerging synthetic insecticides that have been used in various pest management regimens worldwide as alternatives to conventional insecticides. Recently, several studies have indicated that humans are widely exposed to NEOs, but limited is known about the levels and associated health risks of NEOs exposure among children. Objective To estimate exposure levels of four kinds of NEOs in urine samples among 5-year-old children from Laizhou Wan, Shandong Province, and to evaluate health risks of single and cumulative exposure to NEOs among children in this area. Methods A total of 205 children who participated in the 5-year-old follow-up in Laizhou Wan Birth Cohort (LWBC) were included. Urinary concentrations of four NEOs [imidacloprid (IMI), acetamiprid (ACE), clothianidin (CLO), and thiamethoxam (THM)] were measured by high-performance liquid chromatography coupled with triple quadrupole mass spectrometry. Based on the detected NEOs concentrations, estimated daily intake (EDI) was calculated, and the health risk of exposure to single NEO was assessed using hazard quotient (HQ, risk threshold=1). A relative potency factor (RPF) approach was used to standardize the concentrations of the four NEOs by IMI to calculate their cumulative concentrations. Then, the health risk of cumulative exposure to the four NEOs was further evaluated based on the HQ method. Results The detection rates of the four NEOs in the 5-year-old children were all above 90%, and their median creatinine-adjusted urinary concentrations were in the order from high to low as follows: CLO (1.373 μg·g−1) > THM (0.628 μg·g−1) > IMI (0.310 μg·g−1) > ACE (0.073 μg·g−1). Of the four NEOs, the median EDI of IMI was 0.035 µg·kg−1·d−1, higher than those of CLO (0.032 µg·kg−1·d−1), THM (0.012 µg·kg−1·d−1), and ACE (0.002 µg·kg−1·d−1). The maximum HQ values of IMI, CLO, THM, and ACE were 0.168, 0.152, 0.055, and 0.022, respectively, which were all far lower than the risk threshold of 1. The median concentration of cumulative exposure to the four NEOs standardized by IMI was 21.241 μg·g−1, and its median EDI was 2.370 µg·kg−1·d−1. The maximum HQ of cumulative exposure to the four NEOs was only 0.694, which also did not exceed the risk threshold of 1. Conclusion NEOs exposure is common among the 5-year-old children in Laizhou Wan, Shandong. Although there is no obvious health risk associated with single and cumulative exposure to NEOs in the children in this area, their exposure levels of NEOs are higher than those in some foreign areas. The adverse health effects of long-term exposure to low dose of NEOs deserve our extensive attention.