While the effects of ambient pollutants on adverse perinatal outcomes have been studied, most studies have focused on preterm birth, stillbirth, and low birthweight. Few studies have examined the effects of ambient pollutants on prelabor rupture of membranes (PROM). This study was designed to explore the acute effects of ambient pollutants on both term PROM (TPROM) and preterm PROM (PPROM). We enrolled pregnant women receiving antenatal care between October 2013 and December 2019 at the International Peace Maternity and Child Health Hospital (IPMCHH). The effects of ambient pollutants (including PM₂.₅, PM₁₀, SO₂, CO, NO₂, and 8-h O₃) on TPROM and PPROM were estimated using generalized additive models (GAMs). Exposure-response relationship curves were also evaluated using GAMs after adjustment for confounding factors. Potential lagged effects were examined using various lag models. The data of 100,200 pregnant women who delivered at IPMCHH were analyzed. The fitted spline curves for PPROM were similar to the temporal trends of PM₂.₅, PM₁₀, SO₂, CO and NO₂ but not O₃, while those for TPROM were different from the temporal trends of all six air pollutants. An increased risk of PPROM was associated with increased concentrations of PM₂.₅, PM₁₀, SO₂ and CO on lag days 2 and 3, while no association was found between PPROM and daily concentration of O₃. After adjustment for confounding factors, there was a shift in the exposure-response curves, indicating associations between PPROM and PM₂.₅, PM₁₀, SO₂, and CO on lag days 2–3. Interaction effects of PM₂.₅, PM₁₀, SO₂, and CO were also found to increase the risk of PPROM. In conclusion, acute exposures to six critical air pollutants were not associated with an increased risk of TPROM; however, PM₂.₅, PM₁₀, SO₂, and CO were found to interact, increasing the risk for PPROM on lag days 2 and 3.

Manganese (Mn) is an essential trace element, but an excess or accumulation can be toxic. Until now, few studies have examined the effects of maternal Mn level on the risk of spontaneous preterm birth (SPB). The aims of this study were to examine the association between maternal Mn level and the risk of SPB at the early stage of pregnancy, and investigate whether this association was modified by single nucleotide polymorphisms (SNPs) in genes of superoxide dismutase (SOD) and catalase (CAT). We conducted a nested case-control study in three maternal and child health care hospitals in Shanxi province, China, from December 2009 to December 2013. From an overall cohort of 4229 women, 528 were included in our study, including 147 cases of SPB and 381 controls. Maternal blood samples were collected during 4–22 gestational weeks. The maternal serum concentrations of Mn was measured using inductively coupled plasma–mass spectrometry. We found the maternal Mn concentration in the case group (median: 1.55 ng/mL) was significantly higher than that in the control group (median: 1.27 ng/mL). Compared to the lowest level, the SPB risk was significantly increased to 1.44 (95%CI: 0.60–3.43), 2.42 (95%CI: 1.06–5.55) and 2.46 (95%CI: 1.08–5.62) respectively for the second, third and fourth quartiles in first trimester, but not significant in second trimester or overall. When exposure to a high Mn level, women who with AA (6.36, 95%CI: 1.57–25.71) and AG (3.04, 95%CI: 1.59–5.80) of rs2758352, with CC (2.34, 95%CI: 1.31–4.18) of rs699473, and with GG (2.26, 95%CI: 1.22–4.16) of rs769214 were more likely to develop a SPB, but not among women with other genotypes. In conclusion, high maternal serum Mn level is associated with the increased SPB risk in first trimester, and the association is modified by maternal SNPs of SOD2, SOD3 and CAT.

Thallium (TI) is one of the most toxic heavy metals and priority pollutant metals. The emerging TI environmental pollution worldwide has posed a great threat to human health. However, based on the World Health Organization (WHO), the risk and severity of adverse health effects of TI in the range of 5–500 μg/L are uncertain. Moreover, evidence regarding the adverse impacts of TI on children’s health is still insufficient. Herein, we aim to investigate the early adverse effects of TI on children’s health and provide references for the WHO to establish stricter safety limits of TI. From 2015 to 2019, urinary TI and many clinical laboratory parameters related to blood routine, hepatic, renal, myocardial, coagulation function and serum electrolyte were measured in six children aged 1–9 years. The urinary TI concentration ranged from 13.4 μg/L to 60.1 μg/L with a mean of 36.1 μg/L and a median of 34.8 μg/L in six children in 2015. Although only four children felt a little poor appetite, several laboratory abnormalities indicated early damage in liver, renal, and myocardial functions in all children in 2015. After treatment and following up for four years, although the children’s TI concentration decreased below 5 μg/L, their liver and renal functions did not completely recover, and their myocardial function worsened. Results indicated that impaired liver, renal, and myocardial functions were closely associated with elevated urinary TI concentration in children. Considering the increasing use of TI in high-technology industries and emerging TI environmental-contamination zones worldwide, establishing stricter safety limits of TI and paying more attention to the adverse health effects of TI on children are urgently required.We found that a relatively low concentration of thallium (13.4 μg/L to 60.1 μg/L) impaired liver, renal, and myocardial function in six children. After treatment and following up these children for four years, although their urinary TI concentration decreased below 5 μg/L, their liver and renal functions did not completely recover, and their myocardial function worsened.

Particulate matter 2.5 (PM₂.₅) exposures during pregnancy could lead to declined birth weight, intrauterine developmental restriction, and premature delivery, however, the underlying mechanisms are still not elucidated. There are few studies concerning the effects of PM₂.₅ exposure on maternal and child health in Xi'an (one of the cities with severe air pollution of PM₂.₅ in North China). Then, this study aimed to investigate the effect of PM₂.₅ exposure in Xi'an on the offspring birth weights and the possibly associated epigenetic mechanisms. We found the Low and High groups: the offspring with declined birth weights; the decreased mRNA and protein expression of the estrogen receptor (ERs) and eNOs in the uterus; the decreased endometria vascular diameter maximum (EVDM); the increased mRNA and protein expressions of the DNMT1 and 3b in the uterus; the elevated methylation levels of the CpG sites in the CpG island of ERα promoter region in the uterus. However, no differences were observed in the mRNA or protein expressions of ERβ and DNMT3a between the Clean and PM₂.₅ exposure groups, as well as endometriavascular density (EVD). Additionally, PM₂.₅ level was negatively correlated with the ERα protein expression, EVDM and offspring birth weight, as well as the methylation level of the CpG sites in the CpG island of ERα promoter region and the ERα protein expression in the uterus; whereas the ERα protein expression was positively correlated with the offspring birth weight, as well as PM₂.₅ level and the methylation level of the CpG sites in the CpG island of ERα promoter region in the uterus. Taken together, elevated methylation level of the CpG sites in the CpG island of ERα promoter region reduces ERα expression in the uterus, which could be one of the epigenetic mechanisms that pregnant PM₂.₅ exposure reduces the offspring birth weights.

Parabens, known as ubiquitous preservatives, have been linked to adverse health outcomes in humans. This study aimed to examine urinary paraben concentrations of children at 3 years of age and evaluate their associations with anthropometric parameters. Urinary parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP) and benzylparaben (BeP) were measured among 436 children in a birth cohort using gas chromatography with tandem mass spectrometry. Generalized linear models were performed to evaluate associations of paraben exposures with age- and sex-specific z scores, including weight, height, weight for height and body mass index. MeP, EtP and PrP were the dominant parabens in urinary samples, with the median concentrations of 6.03 μg/L, 3.17 μg/L, 2.40 μg/L, respectively. The median values of estimated daily intake (EDIurine) of five urinary paraben concentrations were 12.10, 5.68, 4.50, 0.06 and 0.17 μg/kg-body weight/day, respectively. Urinary EtP concentrations were positively associated with weight z scores [regression coefficient β = 0.16, 95% confidence interval (CI): 0.04, 0.29; p = 0.01] and height z scores (β = 0.15, 95% CI: 0.03, 0.27; p = 0.01). Positive associations were found between the sum of molar concentrations of five parabens and height z scores among all children (β = 0.24, 95% CI: 0.04, 0.45; p = 0.02). These significant associations were only observed in boys. Our findings suggest that exposure to parabens may be adversely associated with physical growth in 3-year-old boy children. Further prospective studies are warranted to understand the toxicological mechanisms of paraben exposures and potential risk of children.

Exposure to ambient air pollution is associated with maternal and child health. Some air pollutants exhibit similar behavior in the atmosphere, and some interact with each other; thus, comprehensive assessments of individual air pollutants are required. In this study, we developed national-scale monthly models for six air pollutants (NO, NO₂, SO₂, O₃, PM₂.₅, and suspended particulate matter (SPM)) to obtain accurate estimates of pollutant concentrations at 1 km × 1 km resolution from 2010 through 2015 for application to the Japan Environment and Children's Study (JECS), which is a large-scale birth cohort study. We developed our models in the land use regression framework using random forests in conjunction with kriging. We evaluated the model performance via 5-fold location-based cross-validation. We successfully predicted monthly NO (r² = 0.65), NO₂ (r² = 0.84), O₃ (r² = 0.86), PM₂.₅ (r² = 0.79), and SPM (r² = 0.64) concentrations. For SO₂, a satisfactory model could not be developed (r² = 0.45) because of the low SO₂ concentrations in Japan. The performance of our models is comparable to those reported in previous studies at similar temporal and spatial scales. The model predictions in conjunction with the JECS will reveal the critical windows of prenatal and infancy exposure to ambient air pollutants, thus contributing to the development of environmental policies on air pollution.

Rising evidence of both experimental and epidemiological studies suggests that phthalate exposure may contribute to increased risks of metabolic disorders. But there is limited research on the childhood dyslipidemia. Our cohort study was conducted in Xiamen city, Fujian Province, China. A total of 829 children (mean age 8.5 years) were included with collection of urine, blood samples and demographic data in May 2018 and followed up once a year from 2018 to 2020. We performed adjusted log-binomial regressions to examine associations between sex-specific tertiles of seven phthalate metabolites and dyslipidemia in visit 1, as well as persistent dyslipidemia and occasional dyslipidemia. We also used generalized estimating equation models (GEE) to explore the relationships between log-transformed phthalate metabolites and lipid profiles. In adjusted models, the prevalence and RRs of dyslipidemia increased with tertile group of mono-n-butyl phthalate (MnBP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), and summed di-(2-ethylhexyl) phthalate (∑DEHP) metabolites with a dose-response relationship in visit 1, as well as persistent dyslipidemia. Higher MnBP, ∑LMWP, MEHHP, MEOHP, and ∑DEHP concentrations were also associated with higher levels of log-transformed triglycerides (TG). Boys were more vulnerable to phthalates exposure than girls. In conclusion, children in China were widely exposed to phthalates, and phthalates exposure during childhood might significantly increase the risk of dyslipidemia and a higher level of lipid profiles, particularly in boys.

Accumulating exposure to quality green space over time is posited to influence child health, yet longitudinal studies are scarce. This study aimed to examine the associations between trajectories of perceived green space quality and child health-related outcomes. We used data from 1874 childrenin the B-cohort of the Longitudinal Study of Australian Children who participated in the Child Health Checkpoint module at 11–12 years. Data on caregiver perceived green space quality measured biennially was assessed using discrete trajectory mixture models to group children by contrasting distributions in green space quality over time. Examination of associations between trajectory groups of perceived green space quality and child biomarkers (i.e., albumin-to-creatinine ratio, total, cholesterol, total triglycerides, and glucose), physical health and behavioural assessments (i.e., anthropometric measurements, blood pressure, sedentary behaviour, physical activity, sleep, aerobic work capacity, and general wellbeing), and health care use were assessed using multilevel models, adjusted for sociodemographic variables. Four perceived green space quality trajectories were identified: “decreasing quality from high to moderate”; “increasing quality from low to high”; “consistently high quality”; “consistently low quality”. Compared with consistently low levels of quality green space, adjusted models indicated consistently high-quality green space was associated with lower total triglycerides (β −0.13; 95%CI -0.25, −0.01). Lower odds of hospital admission was observed among children who accumulated quality green space over time (OR 0.45; 95%CI 0.23, 0.87). These associations were observed in boys only in sex-stratified analyses. Moreover, boys accumulating quality green space through time tended to have lower diastolic blood pressure (β −2.76; 95%CI -5.17, −0.35) and girls who experienced loss in quality green space tended to have a higher percentage of body fat (β 2.81; 95%CI 0.43, 5.20). Accumulating quality green space over time is important for various aspects of child health, with contrasting benefits by sex.

The potential effect of gestational exposure to phthalates on the lung function levels during childhood is unclear. Therefore, we examined this association at different ages (from 4 to 11 years) and over the whole childhood. Specifically, we measured 9 phthalate metabolites (MEP, MiBP, MnBP, MCMHP, MBzP, MEHHP, MEOHP, MECPP, MEHP) in the urine of 641 gestating women from the INMA study (Spain) and the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and FEV₁/FVC in their offspring at ages 4, 7, 9 and 11. We used linear regression and mixed linear regression with a random intercept for subject to assess the association between phthalates and lung function at each study visit and for the overall childhood, respectively. We also assessed the phthalate metabolites mixture effect on lung function using a Weighted Quantile Sum (WQS) regression. We observed that the phthalate metabolites gestational levels were consistently associated with lower FVC and FEV₁ at all ages, both when assessed individually and jointly as a mixture, although most associations were not statistically significant. Of note, a 10% increase in MiBP was related to lower FVC (−0.02 (−0.04, 0)) and FEV₁ z-scores (−0.02 (−0.04, −0.01) at age 4. Similar significant reductions in FVC were observed at ages 4 and 7 associated with an increase in MEP and MnBP, respectively, and for FEV₁ at age 4 associated with an increase in MBzP. WQS regression consistently identified MBzP as an important contributor to the phthalate mixture effect. We can conclude that the gestational exposure to phthalates was associated with children's lower FVC and FEV₁, especially in early childhood, and in a statistically significant manner for MEP, MiBP, MBzP and MnBP. Given the ubiquity of phthalate exposure and its established endocrine disrupting effects in children, our findings support current regulations that limit phthalate exposure.

The aim of this study was to assess the soil contamination caused by potentially toxic elements (Al, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, V, and Zn) using various indices and the associated risk of human health for adults and children in selected soils from Germany (Calcic Luvisols, Tidalic Fluvisols, Haplic Gleysols, and Eutric Fluvisols) and Egypt (Haplic Calcisols, Sodic Fluvisols, and Eutric Fluvisols). Soil contamination degree has been assessed using indices such as contamination factor (CF), pollution load index (PLI), geo-accumulation index (Igₑₒ), and enrichment factor. We also assessed the health risk for children and for male and female adults. Chromium, Cu, As, Mo, Ni, Se, and Zn in the German Fluvisols had high CF of >6, while in the Egyptian Fluvisols Se, Mo, As, and Al revealed a high CF. The PLI (1.1–5.2) was higher than unity in most soils (except for Tidalic Fluvisols), while the most important contributor was Se, followed by Mo and As in the Egyptian Fluvisols, and by Cr, Cu, and Zn in the German Fluvisols. The median value of hazard index (HI) for children in the studied soils indicated an elevated health risk (higher than one), especially in the German Fluvisols (HI = 4.0–29.0) and in the Egyptian Fluvisols (HI = 2.2–5.2). For adults, median HIs in all soils were lower than unity for both males and females. The key contributor to HI was As in the whole soil profiles, accounting for about 59% of the total HIs in all three person groupings. Our findings show that in the studied multi-element contaminated soils the risk for children’s health is higher than for adults; while mainly As (and Al, Cr, Cu, and Fe) contributed significantly to soil-derived health risk.