International Journal of Environmental Health Research最新文献

Understanding Aedes breeding sites is crucial for effective vector control, yet the application of Geographic Information Systems (GIS) and spatial analysis in Kuala Lumpur is limited. This study explores the spatial distribution and characteristics of Aedes aegypti and Aedes albopictus breeding sites in dengue-prone areas of Bandar Tasik Selatan. Entomological data from the Kuala Lumpur Health Department (2022-2023) were analyzed using Average Nearest Neighbor (ANN), Global Moran's I, and Kernel Density Estimation (KDE). Logistic regression and principal component analyses (PCA) were used to assess breeding site characteristics. Of 6,027 water containers inspected, 402 (6.7%) were positive for Aedes larvae. ANN and Moran's I analyses revealed significant clustering in Zone A and Zone B, while KDE identified breeding hotspots. Logistic regression indicated higher risk in plastic (aOR = 69.58), rubber (aOR = 35.11), and cement (aOR = 24.70) containers, while rainwater (aOR = 0.24), tap water (aOR = 0.27), and partial shading (aOR = 0.41) reduced risk. PCA revealed key breeding site variations across residential, public, school, and food areas. These findings support targeted vector control, efficient resource allocation, and tailored interventions to mitigate dengue risks in high-priority areas.

The objective of this study was to examine the influence of air quality (PM_2.5, SO₂, O₃, and NO₂) on daily school absenteeism rates in students with and without asthma in an underserved community with elevated exposure risk. This retrospective study analyzed daily attendance and OAP exposure data from 2015/16 to 2017/18 in an environmental justice area located in Pittsburgh, Pennsylvania. For students with asthma, both long-term (28-day) and short-term (previous day) exposure to these PM_2.5 levels 10.0-12.0 μg/m³ significantly increased absenteeism compared to days with levels below 10 μg/m³ (RR = 1.27, 95% CI 1.10, 1.45 and RR = 1.21, 95% CI 1.03, 1.42, respectively, p < .05). Exposure to unhealthy SO₂ levels (≥75 ppb) also contributed to increased absenteeism (RR = 1.85, 95% CI 1.17-2.92, p < .05). These findings suggest that, while the EPA's recent reduction in the PM_2.5 good air quality standard threshold to 9 μg/m³ represents an important step toward protecting sensitive groups, it does not fully safeguard children in areas prone to frequent exceedances. The study underscores the importance of reducing exposure to outdoor air pollutants in at-risk populations, as inequities in childhood exposure can persist throughout life and disproportionately impact marginalized communities.

Climate change has emerged as a significant global challenge with profound implications for human health. This umbrella review synthesizes findings from systematic reviews and meta-analyses to examine the health impacts of climate change and identify strategies to mitigate these effects. This is an umbrella study conducted in major health and biomedical databases, including PubMed, ISI Web of Knowledge, Scopus, and Google Scholar, for articles published between 2011 and 2021. The search strategy followed the protocol published in BMJ Journal in 2020. The selected articles underwent a rigorous screening process based on predefined inclusion criteria. A total of 37 systematic review articles were included in the study. The thematic analysis identified a range of strategies and policies aimed at mitigating the health effects of climate change, including adaptation measures, public health interventions, and interdisciplinary collaborations. The analysis also revealed significant knowledge gaps in certain areas, highlighting the need for further research. The identified strategies and policies offer valuable insights for policymakers, healthcare professionals, and researchers. By integrating these findings into evidence-based policies and practices, we can enhance our ability to mitigate the adverse health impacts of climate change and promote resilience in the face of this global challenge.

Epidemiological links between air pollution and adverse health outcomes are strong, but the mechanism(s) remain obscure. A newly recognised combustion by-product, environmentally persistent free radicals (EPFRs), may be the missing link. The objective of this study is to explore the presence of EPFRs in house dust and ascertain if EPFR concentration is stable across time and season. The ELLF cohort is a longitudinal birth cohort (n = 82) with house dust collected at multiple time points. EPFR characteristics were assessed with electron paramagnetic resonance, and oxygen-weighted concentration was estimated by an algorithm. Seasonal differences were assessed with Kruskal-Wallis rank sum and Fisher's exact tests. A mixed-effects linear regression was employed for longitudinal analysis. 83 participants returned 238 dust samples, with EPFRs measured in >95% of samples. EPFR concentration and oxygen-weighted concentration were stable across visits (p = 0.05). There was a seasonal trend, with concentration (p = <0.01), oxygen weighted concentration (p = <0.01), and g factor (p = 0.05) all significantly lower in summer months. EPFRs are consistently present in house dust and are stable across time in households. These findings suggest that exposure to EPFRs occurs in the home and may be a significant place for exposure to highly biologically reactive EPFRs.

The unsustainable management of e-waste at recycling and waste disposal sites has become a growing environmental concern, particularly in developing parts of the world. The current study is therefore designed to investigate the concentrations, as well as the associated ecological risks, of eight legacy (PBDEs) and ten alternative halogenated flame retardants (AHFRs) in the leachates and sediments from five recycling centers and seven disposal sites (1 landfill and 6 dumping sites) in Lahore, Pakistan. The results showed that median (min-max) concentrations of both ∑8PBDEs, and ∑10AHFRs were significantly higher (P < 0.05 for all) in the leachates (ng/L) [194.40 (101.85-446.20), 169.72 (84.04-246.11)] and sediments (ng/g) [815.91 (437.96-1624.28), 256.70 (207.16-375.91)] of recycling centers compared to those [33.57 (19.76-57.32), 22.21 (11.66-28.80)] [82.33 (35.70-142.23), 33.66 (17.41-201.37)] from disposal sites, respectively. Principal component analysis revealed that acid digestion, open burning, and dismantling were the primary factors responsible for HFR emissions in the leachate and sediments of recycling centers. The ecological risk assessment indicated a significant threat to the organisms inhabiting the sediments of recycling centers as well as disposal sites. Our results highlight the need to address the emerging concerns associated with HRF releases from e-waste sites to prevent further ecological harm.

This study investigated phytochemical constituents of Ruellia simplex extract and evaluated their molecular interactions with estrogen receptor alpha (ERα) and cytotoxic effects against MCF-7 breast cancer cells. The whole plant was extracted with ethanol and fractionated into methanolic (ME01) and chloroform (CH02) fractions. HR-LCMS identified 11 compounds in ME01 and 8 in CH02, with flavonoids predominating in ME01 and terpenoids in CH02. Molecular docking against ERα (PDB ID: 3ERT) revealed five potent compounds: stigmasterol (-9.0 kcal/mol), apigenin (-8.6 kcal/mol), rosmarinic acid (-8.6 kcal/mol), luteolin (-8.4 kcal/mol), and β-sitosterol (-8.3 kcal/mol). MTT assay demonstrated superior cytotoxicity of ME01 (IC₅₀ = 38.42 ± 2.16 μg/mL) compared to CH02 (52.64 ± 3.05 μg/mL), approaching 5-Fluorouracil (32.18 ± 1.87 μg/mL). Results demonstrate that Ruellia simplex contains bioactive compounds with significant ERα binding affinities and notable cytotoxic activity against breast cancer cells. The ME01 fraction shows promise for developing natural anticancer agents targeting hormone-dependent breast cancers.

The risk of breast cancer in human subjects is associated with the exposure to organochlorines, although the findings have somewhat been inconclusive. A meta-analysis of published peer-reviewed articles was conducted to draw a definitive conclusion about exposure to organochlorine compounds and the incidence of breast cancer, taking into account hospital and population-based case-control studies. Scopus, MEDLINE and Web of Science databases were examined to gather retrospective case-control studies, wherein 16 case-control studies meeting the criteria were included, involving 2960 cases and 2777 controls. Heterogeneity tests, publication bias, sensitivity analysis and trial sequence analysis test were also performed. Chlorinated compounds such as p,p' DDE (p = 0.000, SDM = 4.027: lipid-unadjusted; p = 0.001, SDM = 1.145: lipid adjusted), HCB (p = 0.002, SDM = 2.718), cis-Nonachlor (p = 0.006, SDM = 3.558) and p,p' DDT (p = 0.015, SDM = 1.536: lipid-unadjusted), imposed a significant and positive association with breast cancer. Although compounds like Heptachlor, Dieldrin, γ-HCH, Oxychlordane, and trans-Nonachlor did not reach significant levels, they indicated a possible role in the risk of breast carcinoma. This meta-analysis supports the hypothesis that several organochlorine compounds contribute to an increased incidence of breast cancer.

Vibrio cholerae (V. cholerae) is a type of bacterium that causes cholera, a severe diarrheal disease globally affecting hundreds of people annually. However, the effect of the V. cholerae toxin on oyster metabolite signatures has not been well studied. In this study, nuclear magnetic resonance (NMR) based metabolomics was applied to investigate the metabolic level response of eastern oysters (Crassostrea virginica) to cholera toxin (CT), under low concentrations. Our study demonstrated that the decrease of branched-chain amino acids (BCAAs) in oysters was a response to CT exposure at low concentrations (10 ng/mL) in gill and mantle extracts. Metabolites such as leucine and isoleucine were significantly decreased in gills with toxin exposure at 10 ng/mL, and similar but weaker changes were also observed at 1 ng/mL, indicating an early response to CT. However, the trend reversed at 20 ng/mL, with acetate and propionate significantly increased over control (p < 0.07), which is a sign of antioxidant defenses that could help the recovery of the BCAAs. In the hemolymph study, acetate and propionate levels correlated strongly with those in the tissue extracts at 20 ng/mL, suggesting that hemolymph metabolites begin contributing to gill metabolic perturbations. More importantly, a principal component analysis (PCA) also revealed a partial separation between the control and the 20 ng/mL CT group, indicating potential major perturbations in hemolymph metabolites. This study provides evidence that metabolites in oyster tissues resulting from exposure to Vibrio toxin can serve as a new early warning system for predicting potential human pathogen risks in both environmental and seafood exposure.

Wet shotcreting operations in tunnels produce large amounts of dust that threaten workers' health. In this study, a coupled airflow - dust model was developed based on gas - solid two-phase flow theory to simulate dust migration under different ventilation airflow and shotcreting positions. Using CFD simulations in ANSYS FLUENT and field data validation, the spatiotemporal evolution of dust concentration was analyzed. The results indicate that dust diffusion can be divided into three zones - jet - recirculation, transition, and stable - and that the average dust concentration decreases along the airflow direction, following the order: working face region > shotcreting operation region > transition region > stable region. Increasing ventilation speed effectively reduces peak dust levels and shortens the time to reach permissible concentration. An air duct outlet velocity of 12 m/s (corresponding to a ventilation volume of 1374.1 m³/min and an average tunnel cross-sectional wind speed of approximately 0.64 m/s) is identified as the optimal velocity. Different spraying positions significantly alter dust distribution characteristics, with crown spraying showing the widest and most uneven diffusion. The findings provide a quantitative reference for ventilation optimization and occupational dust control during tunnel shotcreting operations.