Journal of Environmental Health Science and Engineering最新文献

Background

Per- and polyfluoroalkyl substances (PFAS), a class of highly stable synthetic organic compounds, have been detected ubiquitously in human biological samples, raising significant concerns about their safety. The aim of this study was to investigate whether PFAS exposure is associated with higher risk of reproductive cancers.

Methods

Four databases were searched from inception to August 2025. Case-control or cohort studies that examined the association between serum/plasma exposure to five PFAS (perfluorooctanoic acid [PFOA], perfluorooctane sulfonic acid [PFOS], perfluorohexane sulfonic acid [PFHxS], perfluorononanoic acid [PFNA] and perfluorinated sulfonic acids [PFSA]) and reproductive system cancers, including female reproductive system (breast and ovarian cancers) and male reproductive system (prostate and testicular cancers), were included.

Results

21 case-control studies were included. Pooled adjusted odds ratios (aORs) showed no significant association between PFAS exposure and female reproductive cancers. When comparing highest to lowest exposure, pooled aORs were 1.09 (95% CI 0.83–1.43) for PFOA, 1.11 (0.82–1.48) for PFOS, 0.96 (0.68–1.36) for PFHxS, 1.11 (0.79–1.56) for PFNA, and 1.14 (0.46–2.80) for PFSA. PFOS showed a marginal positive association with male reproductive cancers 1.25 (1.02–1.52), whereas PFOA showed no association 0.87 (0.65–1.17). Notably, PFNA per ln-unit increase was significantly associated with female reproductive cancers 1.39 (1.07–1.79) in sensitivity analyses.

Conclusions

Overall, serum PFAS exposure was not significantly associated with female reproductive cancers, though PFNA showed a potential positive association in sensitivity analysis. PFOS may be associated with increased risk for male reproductive cancers.

Polycyclic aromatic hydrocarbons (PAHs) pose serious risks to soil and human health, necessitating effective remediation strategies. This study investigates the efficiency of hybrid ultrasonication-ozonation treatment for the removal of Anthracene (ANT) and Phenanthrene (PHE) from contaminated soils, outperforming individual methods. Experimental results demonstrated that the hybrid method achieved superior removal efficiencies, with maximum values of 70.4% for ANT and 92.0% for PHE at an initial concentration of 350 mg/kg. In contrast, pure ultrasonication reached lower removal rates of 38.9% for ANT and 45.8% for PHE at 390 mg/kg, while ozonation alone achieved 68.4% and 77.1%, respectively. These results highlight the synergistic effect of ultrasonication and ozonation in enhancing PAHs degradation. Machine learning algorithms were developed to predict PAHs removal efficiencies, with the Boosting model achieving the highest predictive accuracy (R² = 0.999 in training and 0.865 in testing datasets). SHAP analysis revealed that Ozone concentration, ultrasonic power, water volume, and initial contaminant concentration were the most influential features. Non-linear relationships and thresholds were observed, particularly for water volume and ultrasonic power, indicating optimal ranges beyond which removal efficiency declined. The study also underscores the critical role of soil texture, especially silt content, in modulating remediation outcomes. These findings provide valuable insights for optimizing PAH removal through advanced oxidation processes.

Climate change in recent years, particularly in the form of increased temperatures and higher evaporation, has contributed to the stress on freshwater resources in arid and semi-arid regions. On the other hand, population growth and increased water demand have made the supply of high-quality water a global challenge. Furthermore, lower energy consumption, along with a reduced carbon footprint, of urban water supply systems has been vital to all communities. In the present study, five different drinking water supply scenarios in a cold, semi-arid city were proposed and compared with a novel methodological approach. The comparison was conducted based on carbon footprint and energy consumption, contrasting each scenario with the existing system. Technical calculations were done on the basis of field data, expertise of concerned authorities, and set standards, while carbon footprints were simulated using SimaPro software. Results show that network-based scenarios, such as dedicated potable water networks and decentralized drinking water stations, have the smallest carbon footprints, while bottled water has the highest emissions. Implementation of bottled water in the studied city would increase daily carbon emissions to over 3,203.1 tons. It was found that the separation of potable water and sanitary water in the current network may lead to the reduction of daily carbon emissions by 130.5 tons, with a possibility of up to 184.1 tons in localized network setups. Ultimately, it is concluded that the adoption of low-carbon, network-based water supply alternatives would reduce energy consumption and operating costs, while also enhancing public health.

Background

Although cigarette butts (CBs) are known as a hazardous waste and an important litter in public environments, the density of littered cigarette butts in rural areas and the concentration of pollutants leaking from them remain a knowledge gap. This study aimed to investigate the difference in cigarette butt density in urban and rural areas of Iran and the environmental consequences caused by the leakage of various pollutants from them, by comparing the Cigarette Butt Pollution Index (CBPI).

Method

Visual surveys were conducted in seven locations in urban environments and sixteen locations in eight villages.

Results

The range of cigarette butt density in urban environments was 0.25/m2 to 0.81/m2 (0.46/m2 on average), while in rural environments, it was 0.8/m2 to 2.33/m2 (1.54/m2 on average). Additionally, the CBPI in rural areas was three times higher than in urban areas, resulting in an average CBPI of 31.24 in rural areas and 10.7 in urban areas. In addition, the higher durability of cigarette butts in rural environments resulted in the leakage of 1.09–2.38 µg/m2 of heavy metals, while the leakage of metals from littered cigarette butts in urban environments was estimated to be 0.065–0.406 µg/m2.

Conclusion

Developing public services such as cleaning systems in rural environments is essential to reduce pollution caused by cigarette butts.

The quality of urban surface waters is strongly influenced by land-use patterns, and changes in the type and intensity of human activities can exert significant impacts on the ecological health of aquatic systems. This study aims to evaluate the effects of land use on the water quality of the Kan River in the western Tehran watershed using the IRWQIsc index and spatial–statistical analyses. To achieve this, land-use maps were updated using Sentinel, Landsat, and Google Earth imagery, and water-quality data were collected from 10 sampling stations during 2024–2025. Land-use characteristics were analyzed within six spatial buffer zones (100, 500, 1000, 2000, 3000, and 5000 m). The results showed a considerable decline in water-quality index scores toward the downstream sections of the river. Agricultural, industrial, and commercial land uses exhibited the strongest associations with increased levels of nitrogenous, phosphorous, and organic pollutants. Redundancy Analysis (RDA) revealed that with increasing spatial scale, the influence of land-use classes on water-quality parameters shifts from point-source to multi-factor patterns. Green spaces and barren lands showed inverse relationships with pollutant concentrations, maintaining their protective role across all spatial scales. The findings underscore the significance of multi-scale spatial analysis for integrated urban water-quality management and provide a foundation for environmental planning and water-resource policymaking in the Tehran metropolitan region.

Purpose

Investigation of Indoor Bioaerosol Concentration (IBC) with potential health risks assesment, with dependence on number of present people, temperature and relative humidity (RH) in school corridor space, which remain under-researched spaces.

Methods

The impact method (AirIdeal 3P) was used for measurements of IBC including α- and β-hemolytic bacteria, Staphylococcus aureus, mannitol(+)Staphylococci, Pseudomonas aeruginosa, mesophiles, psychrophiles, actinomycetes, fungi. Genetical identification of S. aureus and hemolytic bacteria (MecA gene analysis, 16 S rRNA sequencing, and phylogenetic analysis) were performed. Pearson’s correlation was used to assess the association between student occupancy and IBC, while Spearman’s rank correlation was used to evaluate relationships between microclimatic conditions and IBC (p < 0.05).

Results

The highest concentrations of mannitol(+)Staphylococci (2510 CFU m⁻³), S. aureus (1360 CFU m⁻³), and mesophiles (2520 CFU m⁻³) were observed on days with the largest number of students (264). All bacterial groups showed I/O > 1, while fungi showed I/O < 1. Indoors, the highest mean concentration was reached by psychrophiles (1403 CFU m⁻³). Pearson’s correlation was significant for mannitol(+)Staphylococci (r = 0.85), Staphylococcus aureus (r = 0.79), and mesophiles (r = 0.76), showing the dynamic and positive relationship between student number and IBC. MecA gene and 16 S rRNA analysis confirmed the presence of S. aureus. 16 S rRNA and phylogenetic analysis of β-hemolytic bacteria revealed the Staphylococcus (33%), Bacillus (33%), Corynebacterium (20%) as dominant genera. Spearman’s rank correlation revealed a weak correlation between meteorological factors and IBC.

Conclusion

The presence of potential airborne pathogens with proven internal sources underscores the need for detailed monitoring of corridor air quality.

Pharmaceuticals are emerging contaminants that are commonly found in the environment. They can also be found in leachate from landfills, which enters due to improper handling of pharmaceutical waste (throwing it into the trash). This paper aims to review pharmaceutical's occurrence in leachates from municipal landfills with a particular focus on pharmaceuticals planned for monitoring in surface waters in EU countries, as well as to prioritize the environmental risks associated with individual compounds. The data on the occurrence of individual pharmaceuticals in leachates were grouped into anti-inflammatory and analgesic drugs, hormonal drugs, anticonvulsants and antidepressants, and others. A total of 268 study results were identified, containing determinations of 110 pharmaceuticals, drug components and their metabolites. The largest number of studies concerned diclofenac, carbamazepine, ibuprofen and gemfibrozil, where diclofenac and ibuprofen had the highest concentrations in their group. Three of them (diclofenac, carbamazepine and ibuprofen) will be added to the list of priority substances in surface water, according to a proposed amendment to Directive 2008/105/EC on environmental quality standards for water policy. Risk assessment based on a prioritization index revealed that ten pharmaceutical compounds present in landfill leachates pose a very high environmental risk. These include ibuprofen, 17-beta-estradiol, estrone, and diclofenac. Even treated landfill leachates can be a source of pharmaceuticals in surface waters. Therefore, the need to define standards or guidelines regarding limit values ​​for selected pharmaceuticals contained in treated leachates should be considered, with emphasis on substances presenting the highest ecological risk.

Graphical abstract

The dispersion of cough-generated aerosols in enclosed healthcare environments poses a significant risk of airborne transmission, necessitating effective ventilation strategies to safeguard patients and healthcare staff. Conventional ceiling-mounted ventilation systems often fail to rapidly remove particles from the breathing zone, motivating the need for localized airflow enhancement. This study investigates the combined effect of pedestal fan-assisted ventilation and patient coughing inclination on aerosol transport, droplet clearance, and infection risk within a dental room. A transient computational fluid dynamics (CFD) model was developed to simulate the evolution of cough-generated droplets under varying patient inclinations and different fan speeds. The results reveal that particle transport is governed by the interplay of cough jet momentum, aerodynamic drag, turbulent dispersion, and gravitational settling. At 0°, droplets remain suspended, resulting in the highest infection risk, exceeding 75% under low airflow conditions. With a 30° inclination, the risk decreases to 64%, while at 45° it further reduces to 42% under low airflow and to 26% under high airflow, confirming the optimal alignment of cough momentum with ventilation streamlines. The droplet number fraction also shows the greatest reduction at 45°, decreasing by 21.5% under low airflow and by 28.4% under high airflow compared to 0°. Larger droplets consistently settle due to gravity, whereas smaller aerosols remain entrained until cleared by the outlet-directed airflow. The findings demonstrate that optimizing patient inclination, particularly at 45°, in conjunction with higher fan speeds, significantly enhances particle clearance and reduces infection risk. This approach can be effectively applied in dental clinics and similar indoor settings, where quick aerosol control is essential to reduce the risk of cross-infections.

Background

As the global burden of glaucoma continues to rise, evidence suggests factors beyond intraocular pressure contribute to its pathogenesis. Environmental pollutants are increasingly implicated in ocular disease, yet the association between dichlorophenol exposure and glaucoma remains unexamined. This study addresses this gap by analyzing NHANES data to investigate their relationship, providing new evidence for disease prevention and environmental intervention.

Methods

The data originated from the National Health and Nutrition Examination Survey (NHANES, 2005–2008). To explore the connection between urinary dichlorophenol levels and glaucoma, we conducted weighted logistic regression analyses. Additionally, to examine potential nonlinear associations, restricted cubic splines (RCS) were utilized. We further performed subgroup analyses to investigate interaction effects.

Results

There were 1,742 participants. The risk of glaucoma was significantly associated with higher ln-transformed urinary 2,4-dichlorophenol levels (OR = 1.39; 95% CI: 1.11–1.74; P = 0.002), as were Ln-transformed urinary 2,5-dichlorophenol levels (OR = 1.28; 95% CI: 1.09–1.51; P = 0.001). Participants in the third tertile of 2,4-dichlorophenol were at a greater risk for glaucoma compared to the first tertile (OR = 2.11; 95% CI: 1.07–4.17; P for trend = 0.042), according to the completely adjusted model. Similar results were observed for the levels of 2,5-dichlorophenol (OR = 2.15; 95% CI: 1.03–4.48; P for trend = 0.039). RCS demonstrated the nonlinear connection between urinary dichlorophenol levels (2,4-dichlorophenol and 2,5-dichlorophenol) and glaucoma risk (P for nonlinearity < 0.05).

Conclusions

Our results demonstrated a strong nonlinear positive association between urinary dichlorophenol levels and glaucoma risk. Given the global prevalence of dichlorophenols and the universal burden of glaucoma, these findings provide a valuable reference for international counterparts investigating similar environmental-ocular health links.

Purpose

Following reports of an adverse link between glyphosate and bone mineral density (BMD), this cross-sectional study extended the investigation between glyphosate exposure and BMD to include osteoporosis, and fractures, with a focus on the high risk, post-menopausal female subgroup.

Methods

Cross-sectional data from 2,710 participants of the US National Health and Nutrition Examination Survey aged 8–59 years from 2013 to 2018 were used to assess associations between urinary glyphosate concentration (µg/L) and BMD (g/cm²) was measured using dual-energy X-ray absorptiometry (DXA), while osteoporosis and fractures were self-reported. Linear and logistic regression analyses were adjusted for age, race/ethnicity, BMI, smoking status, and income.

Results

There was a negative association between glyphosate and BMD in the entire population (Whole Body BMD slope = -0.018; 95% CI = -0.027, -0.010; p < 0.001; Lumbar Spine BMD slope = -0.019; 95% CI = -0.030, -0.007; p = 0.002). In the high-risk, post-menopausal female subgroup, there was an inverse relationship (Whole Body BMD slope = -0.044; 95% CI = -0.076, -0.012; p = 0.009; Lumbar Spine BMD slope = -0.048; 95% CI = -0.101, 0.004, p = 0.069). Additionally, post-menopausal females with higher glyphosate had greater odds of self-reported osteoporosis (adjusted odds ratio (AOR) = 2.57; 95% CI = 1.24, 5.34; p = 0.011) and of self-reported fracture (AOR = 2.14; 95% CI = 1.28, 3.58, p = 0.004).

Conclusions

Results are internally consistent and align with existing literature concerning toxicity of glyphosate on bone and extend it to include adverse impact on osteoporosis and fractures. Given the cross-sectional design and single point of sampling, longitudinal studies with repeated sampling are recommended to evaluate causation.