International Journal of Environmental Health Research最新文献

Microorganisms involved in composting can become airborne during turning-over and screening, potentially impacting the health of workers and nearby residents. This study investigated bioaerosol emissions at a municipal solid waste composting facility and their associated health risks. Air samples were collected at multiple locations, from 100 m upwind of the facility to 100 m downwind of the facility boundary, to assess bacterial and fungal concentrations. The highest bioaerosol levels with a mean concentration of 9307 CFU/m³ and 763 CFU/m³ for bacteria and fungi, respectively, were observed at the turning-over site, followed by the screening area. Bioaerosol concentrations declined with distance from the turning-over site, and at 250 m downwind, bioaerosol levels fell below background concentrations, indicating a safe zone for surrounding communities. Environmental factors such as wind speed influenced bacterial emission from composting piles, while temperature is negatively correlated with fungal concentrations in ambient air, likely due to low humidity in the semi-arid climate. The findings indicate that certain composting stages release elevated bioaerosol levels, particularly bacteria, posing potential health risks to workers. However, exposure risks for nearby residents appear minimal, and fungal bioaerosols pose a low risk due to reduced spore survival under low-humidity conditions of semi-arid regions.

Antibiotic resistance has emerged as one of the most significant public health concerns of the twenty-first century. The excessive and inappropriate use of antibiotics has accelerated the proliferation of antibiotic-resistant bacteria (ARB) and genes (ARGs). Rapid urbanization and anthropogenic activities further facilitate the dissemination of ARB and ARGs into downstream river ecosystems through the discharge of treated effluents from wastewater treatment plants (WWTPs). The study investigates the occurrence, seasonal variations, and distribution of selected ARGs (blaNDM-1, blaSHV, blaCTX-M, ermB, qnrS, and vanA) and intI1 gene in WWTPs and downstream river environments. Samples (inlet, treated wastewater, and activated sludge) were collected during the winter and summer seasons over 1 year from three WWTPs employing different treatment technologies, as well as from the Ganges River (water and sediment) in North Indian cities: Kanpur, Prayagraj, and Varanasi. The results indicated that WWTPs significantly reduced ARB and ARG levels in treated effluents, a marked increase in their abundance was observed in the downstream Ganges River environment. These findings highlight that WWTPs may serve as potential hotspots for the dissemination of ARB and ARGs into the freshwater ecosystems, underscoring the urgent need for advanced treatment and monitoring strategies to mitigate antibiotic resistance spread.

We searched Web of Science, Scopus, PubMed, and Embase (2000-2025) for studies reporting ClO₄^- levels in drinking water. Data on country, water source type, concentration (mean/SD), and analytical methods were extracted. A random-effects meta-analysis was performed to estimate pooled ClO₄^- concentrations. Non-carcinogenic risk was evaluated using the Hazard Quotient (HQ), with Monte Carlo simulation (MCS) model to account for uncertainties in exposure parameters (concentration, ingestion rate, body weight). The meta-analysis revealed significant regional variability, with the highest ClO₄^- concentrations in the United Arab Emirates (370.05 μg/L), Chile (96.82 μg/L), and India (80 μg/L), exceeding WHO and USEPA guidelines. Groundwater had substantially higher levels (pooled mean: 5.55 μg/L) than surface water (0.22 μg/L). Probabilistic risk assessment identified elevated HQ values ( >1) in the UAE (17.67), Chile (5.56), India (3.08), Namibia (2.55), and Japan (1.25), indicating potential thyroid disruption risks. In contrast, most European and East Asian countries showed negligible risk (HQ < 1). ClO₄^- contamination in drinking water poses significant health risks in regions with high industrial activity, arid climates, or natural geological deposits. Groundwater is particularly vulnerable due to prolonged accumulation. Regulatory measures, advanced treatment, and targeted monitoring are urgently needed in high-risk areas to mitigate exposure.

This study measured nitrite concentrations in eighty groundwater samples collected from Sohag Governorate, Egypt, and assessed the biochemical effects of nitrites on male rats. The Nazat El Hajer well in Juhayna City showed the highest nitrite concentration (0.92 mg/L), exceeding the allowable long-term exposure limit of 0.2 mg/kg. Additionally, we assessed the palliative effects of vitamin C and cod liver oil, as antioxidants, in reducing nitrite-induced toxicity in male rats. Seventy-five adult male rats were divided into five groups; GI: control; GII: drinking water (Nazat El Hajer) for 3 months; GIII: sodium nitrite (80 mg/kg BW) for 3 months; GIV: sodium nitrite for 45 days followed by vitamin C (80 mg/kg BW) daily for 45 days; GV: sodium nitrite for 45 days followed by cod liver oil (80 mg/kg BW) daily for 45 days. Results showed a significant increase in serum AST, ALT, ALP, creatinine, urea, and interleukin-6, along with a significant decrease in TAC, catalase, albumin, cytochrome-c- oxidase, hemoglobin, and RBCs in the nitrite-treated groups. These findings indicate that high concentrations of nitrites caused marked hepatic and hematologic toxicity. Furthermore, both the vitamin C and cod liver oil groups exhibited significant improvement in all measured parameters.

This study examines the concentrations of potentially toxic elements (PTEs) in frequently consumed spices using inductively coupled plasma - optical emission spectroscopy (ICP-OES). The risk assessment of exposure to these metals was also investigated through probabilistic Monte Carlo simulation to estimate non-carcinogenic and carcinogenic risks. The findings indicated that the highest PTEs concentrations were found in curry (189.27 mg/kg), while turmeric had the lowest levels (111.87 mg/kg). Mn had the highest concentration among all the spices, followed by Fe (with the exception of black pepper), while Cd had the lowest concentration through spices (0.7 mg/kg). Moreover, for all spices, several metals' levels in packaged types were significantly higher than in bulk types. The findings also depicted that children are at greater risk than adults. The results showed that while non-carcinogenic risks were within acceptable limits (below 1), arsenic exposure through spice consumption posed a carcinogenic risk, particularly for children (greater than 1.00E-4). However, our findings showed that total target hazard quotient (TTHQ) for the cumulative risk of all spices consumption were 1.45 and 2.84 for adults and children, respectively, indicating considerable non-carcinogenic risk. Overall, the study underscores the need for stricter regulations of toxic element levels in spices to ensure food safety.

Giardia is a widespread intestinal protozoan infecting both humans and livestock, and is notable for its zoonotic transmission potential. This study aimed to assess the genetic assemblages of Giardia in cattle, sheep, and goats slaughtered in Jahrom, Iran. A total of 540 fecal samples from slaughtered 90 cattle, 247 sheep, and 203 goats were initially screened for Giardia cysts using microscopy and nested PCR targeting the glutamate dehydrogenase (gdh) gene was performed. Microscopic analysis of fecal samples revealed that 35 samples (6.5%) were positive for Giardia cysts. The overall prevalence of infection was 6.9% in sheep and goats, and 4.4% in cattle. Out of 20 isolates selected for molecular characterization, 12 were successfully sequenced, identifying assemblages AI (n = 5), AII (n = 1), and E (n = 6). All assemblage A and five assemblage E samples were associated with formed stools, while one assemblage E isolate was linked to diarrhea. Phylogenetic analysis showed that assemblage A isolates were related to human, animal, and environmental strains. Prevalence was significantly higher in younger animals and was also associated with stool consistency. The presence of assemblage A underscores a zoonotic risk, emphasizing the need for monitoring and control in livestock to reduce human infection.

The growing demand for eco-friendly nanomaterials has accelerated interest in green synthesis strategies using medicinal plants. In this study, copper oxide nanoparticles (CuO NPs) were synthesized with an aqueous extract of Origanum vulgare as a natural reducing and stabilizing agent in a simple, low-cost, and sustainable bioprocess. The nanoparticles were characterized by FTIR, XRD, SEM-EDS, and TGA-TDA, confirming their nanocrystalline structure, monoclinic phase, and thermal stability. Surface functionalization with phytochemicals was evidenced by FTIR and elemental analyses, indicating strong Cu - biomolecule interactions. Phytochemical assays confirmed retention of phenolics, flavonoids, and tannins, while mineral profiling (ICP-AES, WD-XRF) revealed Ca, Mg, Fe, and Cu contributing to nucleation. HPLC-UV-MS identified bioactive compounds such as rosmarinic acid and rutin. Functionally, the CuO NPs exhibited strong antioxidant activity (DPPH, ABTS, FRAP) and broad-spectrum antimicrobial efficacy against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and fungi (Aspergillus flavus, Botrytis cinerea), surpassing the aqueous extract. These activities, attributed to reactive oxygen species (ROS) generation and Cu²⁺-biomolecule interactions, highlight the biocatalytic role of plant metabolites in nanoparticle functionality.

This study presents a comprehensive assessment of metals in surfacewater of Ondo Town, Nigeria. Surfacewater samples (n = 20) were collected and analyzed for physicochemical parameters. Physical parameters include pH, temperature (^oC), electrical conductivity (EC) and total dissolved solids (TDS) were measured using a handheld pH meter on field while metals (Fe, Pb, Cu, Cr, Mn, Zn, Ni, Co, and Cd) were analyzed using flame atomic absorption spectrophotometry (FAAS). Results revealed that the values of pH in the surfacewater is between 6.93 and 7.61 while the temperature is between 28.50°C and 33.24°C. TDS in the water is between 77.00 mg/l and 1446.00 mg/l while EC is between 152.00 µS/cm and 2902.00.00 µS/cm. The study showed elevated concentrations of Fe (0.12-7.54 mg/l), Pb (0.01-0.99 mg/l), Cr (0.01-0.13 mg/l), and Cd (0.002-0.004 mg/l) exceeding WHO limits in several samples. Multivariate statistical analyses identified weathering, agricultural runoff, and industrial effluents as major contamination sources. Pollution indices indicated moderate to very high contamination. Potential ecological risk assessment (PERI) highlighted considerable risks from metals. Health risk assessment revealed higher non-carcinogenic risks (HQ > 1) for children due to Pb and Co exposure. The study underscores the need for stricter industrial regulations to mitigate contamination.

Mosquito blood meal analysis is critical for understanding vector-borne disease transmission. This study provides the first molecular evidence of host-feeding patterns in the climatically diverse Golestan Province, northeastern Iran. From April to December 2023, 491 female mosquitoes (51 Anophelines, 440 Culicines) were collected across nine locations. Blood-fed specimens (n = 42) were analyzed using multiplex-PCR to identify vertebrate hosts, targeting humans, bovines, horses, goats, dogs, cats, chickens, and rats. Culex tritaeniorhynchus (n = 26) showed a strong pattern for humans (53.8%) and bovines (30.8%), with 26.9% mixed meals. Anopheles hyrcanus (n = 9) predominantly fed on humans (88.9%), with 33.3% mixed meals including goats and chickens. Culex pipiens s.l. (n = 5) equally favored humans and bovines (60.0% each), while Culex theileri (n = 1) and Anopheles maculipennis (n = 1) fed on goats and humans, respectively. Cx. tritaeniorhynchus, Cx. pipiens s.l. and An. hyrcanus feed on both humans and animals and could act as bridge vectors for zoonoses. In Golestan, this suggests zoonotic risk and need for stronger vector surveillance and control, especially for An. hyrcanus and Cx. tritaeniorhynchus. Because sample sizes were small, however, these findings should be interpreted cautiously and confirmed by larger, multi-seasonal, multi-site studies.

Fluoride is recognized for its dental health benefits; however, excessive intake during infancy may pose risks such as dental fluorosis. This review evaluated fluoride levels in breast milk (BrM), influencing factors, and potential health effects in infants. The methodology involved searching PubMed, Scopus, Web of Science, IranDoc, Science Direct, and Google Scholar for studies published from 1974 to 2025. The search strategy included Medical Subject Headings (MeSH) terms and free-text keywords - such as "fluoride," "breast milk," "breastfeeding," 'human,"and "level," along with other relevant terms - combined with Boolean operators (AND/OR) for a comprehensive literature search. Inclusion criteria: peer-reviewed studies with original data on fluoride in BrM. Exclusion criteria: informal reports, reviews, and studies without primary data. Of the 204 records, 9 studies were included in the final analysis. Lacking raw data, values were re-simulated in Excel (2016) using mean, standard deviation, and sample size. Results showed that the mean fluoride in BrM met the European Food Safety Authority (EFSA) guideline (100 µg/L) in 12 of 19 cases (63.2%), with 36.8% outside this range. The health risk assessment showed that, for one-month-old infants, the hazard quotient (HQ) exceeded the permissible limit (HQ = 1) in 7 of 19 cases (36.8%).