International journal of hygiene and environmental health最新文献

Background: Lead exposure remains a substantial risk to public health, especially among children, in low- and middle-income countries. This study assessed the efficacy of a soil remediation intervention on reducing blood lead level (BLL) among children living near an abandoned used lead-acid battery (ULAB) recycling site in Mirzapur, Bangladesh.

Methods: We conducted a pretest-posttest, non-equivalent comparison group study with 167 children aged 6 months to 12 years across three study arms (ULAB intervention, ULAB control, and non-ULAB control). Blood and environmental samples were collected at baseline and 12 months post-intervention. BLL was analyzed by Graphite Furnace Atomic Absorption Spectrophotometry, and environmental lead levels were assessed using portable X-ray fluorescence analyzer.

Results: Over the 12-month post-intervention period, geometric mean BLLs declined from 90.1 to 70.4 μg/L in ULAB intervention group, from 88.5 to 81.1 μg/L in ULAB control group, and from 42.8 to 37.8 μg/L in non-ULAB control group. Difference-in-differences analysis revealed a 15% greater BLL decline in the intervention arm compared to the ULAB control arm and 11% greater BLL decline in the intervention arm compared to the non-ULAB control arm. Subgroup analysis in the intervention arm revealed that older children (>5 years), those living closer to the site (<200m), and those with higher baseline BLL (>median) experienced the greatest reduction in BLL.

Conclusion: The soil remediation intervention significantly reduced BLLs in children. However, levels remained above the CDC reference value of 35 μg/L, highlighting the need for broader and sustained public health initiatives to reduce lead exposure.

Per- and polyfluoroalkyl substances (PFAS) are associated with reduced vaccine immune response, though most observational studies have found no link to COVID-19 vaccine response. Residents of North Carolina's Cape Fear River Basin have elevated serum PFAS levels. We investigated the cross-sectional association between serum PFAS and anti-Spike SARS-CoV-2 IgG (anti-S IgG) levels among COVID-19-vaccinated adults (N = 330) from three communities of the GenX Exposure Study with elevated PFAS. Eligibility criteria included no prior COVID-19 diagnosis and receipt of ≥2 COVID-19 vaccinations, the most recent within 180 days of data collection (June-November 2021). Serum PFAS (liquid chromatography-high resolution mass spectrometry) and anti-S IgG (AdviseDx SARS-CoV-2 IgG II Assay) were measured. For five PFAS with >85 % sample detection, we built general linear models of log-transformed PFAS and anti-S IgG for each community, adjusting for age, sex, and days since last vaccination. Most participants were mid-aged, female, and White. COVID-19 vaccination patterns (i.e., doses, manufacturer) and anti-S IgG levels varied by community. Modest positive and negative estimates of PFAS-anti-S IgG relationships were observed across communities and PFAS. One community (Lower Cape Fear River region) had the largest, and only statistically significant, estimate: 0.31 % (95 % CI: 0.07 %-0.56 %) increase in anti-S IgG per 1 % increase in PFHpS (PFAS with lowest median concentration). We observed no consistent evidence linking higher serum PFAS to lower COVID-19 vaccine response, aligning with prior studies. Assessing PFAS exposure and COVID-19 vaccine response in observational studies is challenging. Longitudinal studies with serial antibody measurements, and vaccine type considerations, might provide additional insight.

Among children and adolescents, exposure to per- and poly-fluoroalkyl substances (PFAS) and their substitutes remains poorly characterized. This study analyzed major PFAS and their substitutes in serum samples from 257 children (6-12 years) and 283 adolescents (13-18 years) using the Korea Ministry of Food and Drug Safety biospecimen archive. Eleven compounds, including PFHpA, PFOA, PFNA, PFOS, and 9Cl-PF3ONS, were detected in over 70 % of the participants, with several legacy PFAS detected at levels exceeding those reported elsewhere. Among the study population, PFOA, PFHxS, and PFOS exhibited the highest concentrations, and children generally showed higher levels than adolescents. Notably, 85 % and 4 % of participants showed PFOA levels that exceeded HBM-1 and HBM-2 values, respectively. Among the substitutes, 9Cl-PF3ONS was detected in all participants, while 6:2FTS, a precursor, was present in more than half of the participating subjects (>55 %). PFAS levels, particularly those of PFOA and PFOS, were significantly higher among individuals consuming tap water compared to those relying on bottled water (p < 0.05). This likely reflects the higher contamination levels of surface water, the primary source for tap water, compared to groundwater, which is commonly used for bottled water in South Korea. Additionally, dietary intake, particularly seafood and meat consumption, was associated with elevated PFAS levels. The present findings highlight the high and widespread exposure to PFAS among Korean youth, emphasizing the need for further research to identify exposure sources and implement mitigation strategies to reduce PFAS exposure.

Prenatal pesticide exposure may adversely affect child neurodevelopment which may partly arise from impairing the placenta's vital role in fetal development. In a cohort of pregnant farmworkers from Thailand (N = 248), we examined the links between urinary metabolites of pyrethroid pesticides during pregnancy, placental gene expression networks derived from transcriptome sequencing, and newborn neurobehavior assessed using the NICU Network Neurobehavioral Scales (NNNS) at 5 weeks of age. Focusing on the 21 gene network modules in the placenta identified by Weighted Gene Co-expression Network Analysis, our analysis revealed significant associations between metabolites and nine distinct modules, and between thirteen modules and NNNS, with eight modules showing overlap. Notably, stress was negatively associated with the interferon alpha response and Myc target modules, and the interferon alpha response module was correlated positively with attention, and negatively with arousal, and quality of movement. The analysis also highlighted the early and late trimesters as critical periods for the exposures influence on placental function, with pyrethroid metabolites measured early in pregnancy significantly negatively associated with the protein secretion module, and those measured later in pregnancy negatively associated with modules related to oxidative phosphorylation (OXPHOS) and DNA repair. Additionally, the cumulative sum of 3-phenoxybenzoic acid across pregnancy was significantly negatively associated with the OXPHOS module. These findings suggest that prenatal exposure to pyrethroids may influence neonatal neurobehavior through specific placental mechanisms that impact gene expression of metabolic pathways, and these effects may be pregnancy period specific. These results offer valuable insights for future risk assessment and intervention strategies.

This prospective cohort study investigated the impact of maternal exposure to endocrine-disrupting chemicals, specifically phthalates and bisphenol A (BPA), on infant neurodevelopment. From 2019 to 2022, 672 pregnant women consented to participate in the study during their initial prenatal appointments at the Obstetrics and Gynecology Clinic of King Faisal Specialist Hospital & Research Centre. Two urine samples were collected each trimester to measure seven phthalate metabolites and BPA levels. Neurodevelopmental performance was evaluated using the Ages & Stages Questionnaires® Third Edition at 6, 12, and 18 months of age, and the risk of autism was assessed with the Modified Checklist For Autism in Toddlers at 18 months. Linear mixed models and logistic regression were applied to evaluate trimester-specific and overall associations using natural log-transformed urinary concentrations of phthalates and BPA. Our results showed that each one-unit increase in the log-transformed concentration of specific phthalates and BPA was associated with significant changes in infant developmental scores. During the first trimester, elevated levels of mono-n-butyl phthalate (MnBP), mono-iso-butyl phthalate (MiBP), and BPA were associated with 4.3 %-5.6 % decreases in gross motor (GM) scores. In contrast, monoethyl phthalate (MEP) and low-molecular-weight (∑LMW) phthalates were linked to 4 %-4.5 % increases in communication (COMM) scores. In the third trimester, MECPP and Σ₃DEHP were positively associated with GM and fine motor (FM) scores, while MiBP was associated with reduced personal-social (PSoc) scores. Sex-stratified analyses revealed differences in susceptibility, with males showing stronger adverse associations in problem-solving and social domains and females more affected in gross and fine motor scores. Mediation analysis identified free thyroxine (FT4) as a partial mediator, accounting for 12.7 % of the effect of ∑LMW phthalates on COMM scores during the first trimester. However, most mediation effects through maternal thyroid hormones were small and not statistically significant. Additionally, some first-trimester exposures, such as MEP and mono-(2-ethyl-5-oxohexyl) phthalate, appeared to be associated with lower odds of a positive M-CHAT screen. At the same time, MnBP showed a potential increase in risk. However, these exploratory findings were based on crude models and a limited number of positive cases and should be interpreted cautiously. Our study also examined overall exposure to phthalates and BPA across pregnancy, revealing consistent yet subtle impacts across developmental domains. This study adds novel insights by assessing trimester-specific exposures and investigating maternal thyroid hormones as potential mediators of early neurodevelopmental outcomes.