Bisphenols are endocrine disruptors that may be associated with altered fetal growth in humans, and they have similar biological functions to mimic hormones. In addition, aggregated chemicals showed an adverse effect although individual concentration was at a low level. However, most studies between bisphenols and birth outcomes have focused on the effect of individual bisphenol. Thus, we explored the associations of urinary bisphenol mixtures with birth outcomes. We conducted a prospective birth cohort study in South Korea. One hundred eighty mother-infant pairs were recruited from 2017 to 2019. Bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS) in one spot urine were analyzed using ultra-performance liquid chromatography–tandem mass spectrometry. We used two statistical approaches to examine potential associations of BPA, BPF, and BPS with birth weight and gestational age: (1) multivariable linear regression; (2) Bayesian kernel machine regression (BKMR). The geometric means of BPA, BPF, and BPS were 2.1, 0.2, and 0.1 μg/L, respectively. In stratified linear analyses by each median value, a higher BPF was positively associated with birth weight (g) (β = 125.5; 95% CI: 45.0 to 205.9). Mixture analyses using BKMR suggested an inverse association between bisphenol mixtures and birth weight. Our findings suggest that in utero bisphenol exposure may influence birth weight and that such relationships may differ considering non-linearity and the combined effect.

Background: The popularity of heated tobacco products (HTPs) has been growing globally but, limited information exists on tobacco use behaviors and its impact on tobacco control. This study investigates awareness and perception of HTPs among tobacco users, and whether perceptions of HTPs are associated with HTP use and intention to quit.Methods: 2,000 tobacco users aged 19–65 years with countrywide representation were invited to an online survey in November 2018. Information on general characteristics, tobacco use behaviors, awareness and perception of HTPs, and intention to quit, were gathered. Multinomial logistic regression analysis and ANCOVA were used for estimation of association and comparison.Results: Among all tobacco users, 36.8% were classified as ever users, whereas 28.3% had used HTPs in the past 30 days, which was higher than expected. Users of liquid-based e-cigarettes (OR: 1.578; CI: 1.210–2.056) and poly product (OR: 2.029; CI: 1.121–3.671) showed higher intention to quit within 1 month when compared to users of conventional cigarettes (CCs), whereas HTP users and dual product users did not. HTP users rated HTPs more favorably than CCs in terms of smoke, smell, harm, aid in quitting, design, and price than users of other products did (p-value <0.001).Conclusions: We find that positive perception of HTPs following strategic marketing from tobacco companies could have contributed to an increase in HTP use than expected in Korea. However, HTPs might not be considered substitutes for CCs for quitting tobacco use because a significant proportion of dual product users reported a lower intention to quit.