International Journal of Environmental Health Research最新文献

This study aimed to investigate the biological activity, antioxidant, and antibacterial capacities of Cymbopogon citratus essential oils (CEO), as well as their effects on in vitro rumen fermentation and methane emissions using breed rumen liquor. Eighteen compounds were identified in the leaves, with E-citral (46.44%), Z-citral (39.91%), and geraniol (3.99%) being the principal components. CEO exhibited a higher antiradical capacity (IC₅₀ = 92 µg/ml) compared to the methanol extract (IC₅₀ = 290 µg/ml). Enterococcus faecalis was the most sensitive strain to CEO, showing the largest inhibition zone (IZ = 40 mm). Inclusion of CEO at 5 µL/mL positively affected in vitro fermentation, with optimal values for parameters (V24, VFA, ME, and DMO) at this dose; values decreased at higher concentrations. Methane production decreased significantly with increasing essential oil concentration, with reductions of 21%, 20%, and 18% for 5, 10, and 20 µL/mL doses, respectively. CEO demonstrated greater activity against Gram-positive bacteria and significant antifungal activity against Candida albicans. These findings suggest that C. citratus leaves possess antioxidant, antimicrobial, and antibacterial properties, indicating potential as antiparasitic agents in sheep.

This study investigated the relationship between employment in industries vulnerable to air pollutant exposure and the county-level prevalence of diabetic retinopathy (DR) in the United States. A cross-sectional dataset of 3,127 counties was assembled by integrating 2020 emissions data for seven major ambient pollutants (NOₓ, PM₂.₅, PM₁₀, CO, NH₃, SO₂, and VOCs) with 2021 modeled DR prevalence estimates and 2020 workforce composition indicators from nationally representative datasets. Spatial autoregressive models were used to account for spatial dependence in county-level health outcomes. The results showed that a 1% increase in employment in agriculture, forestry, fishing & hunting, and mining was associated with a 0.01% increase in the prevalence of vision-threatening DR. Similarly, each 1% increase in employment in the transportation, warehousing, and utilities sectors corresponded to a 0.02% increase in DR prevalence. Overall, the findings suggest that counties with higher concentrations of workers in pollutant-intensive industries experience elevated burdens of vision-threatening DR, underscoring the need to consider both environmental and occupational factors in efforts to reduce geographic disparities in diabetes-related eye disease.

Evidence regarding the cumulative impact of exposure to diverse volatile organic compounds (VOCs) on frailty remains limited. We aimed to explore the association between VOCs and frailty, and to investigate the mediating effects of oxidative stress and inflammation. Our study involved 4,677 participants aged ≥20 from the National Health and Nutrition Examination Survey (NHANES). Multivariable logistic regression, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were employed. We further conducted mediation analysis to explore the mediating role of oxidative stress and inflammation. Multivariable logistic regression revealed several VOCs were significantly correlated with frailty, particularly for N-Acetyl-S-(2-carboxyethyl)-L-cysteine (CEMA), N-Acetyl-S-(2-cyanoethyl)-L-cysteine (CYMA), N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), mandelic acid (MA), N-Acetyl-S-(4-hydroxy-2-buten-1-yl)-l-cysteine (MHBMA3) and N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (HPMMA). WQS regression confirmed synergistic effects of combined VOCs exposure on frailty (OR = 1.53, 95%CI: (1.28, 1.83)), with four mVOCs (DHBMA, CEMA, HPMMA and CYMA) contributing most substantially. BKMR analysis further identified this positive correlation, and the association was more significant in the older group. Mediation analysis showed these relationships were partially mediated by oxidative stress and inflammatory pathways. This study offers novel evidence for a positive correlation between VOCs and frailty, with DHBMA being the most significant contributor. Oxidative stress and inflammation potentially act as mediators.

Environmental conditions significantly influence dengue fever transmission by affecting Aedes mosquito breeding. This systematic review aimed to identify and synthesize environmental health factors associated with dengue risk. A comprehensive search across multiple databases yielded 64 studies conducted in urban, peri-urban, and rural settings. Data were extracted and categorized thematically, and risk of bias was assessed using the JBI Checklists, Newcastle-Ottawa Scale, and ROBINS-I tool, depending on study design. Eight key environmental health factors were identified: water storage practices, solid waste disposal, housing characteristics, drainage and standing water, vegetation and shaded areas, urbanization and population density, climate and seasonal variation, and water supply reliability. Improper water storage and unmanaged waste were consistently linked to higher mosquito entomological indices. Poor housing conditions and densely populated urban areas also correlated with increased dengue risk. Seasonal rainfall and unreliable water infrastructure intensified vulnerability, particularly in resource-limited contexts. Findings emphasize that environmental health conditions are central to dengue prevention. Effective control requires multi-sectoral strategies that integrate infrastructure upgrades, environmental management, and behavioural change. Future research should prioritize evaluating environmental interventions and developing predictive models incorporating climate, infrastructure, and human behaviour to guide public health responses.

Diarrhoea is one of the primary causes of mortality in under-five-children in developing regions. Poor sanitation practices and the consumption of water from unsafe sources contribute to the prevalence of this preventable disease among children. This study aimed to investigate the factors associated with poor sanitation and drinking water facilities and their contribution to diarrheal-related infections among children in South Africa, utilizing data from the 2019 General Household Survey. This quantitative study employed chi-square and logistic regression analyses to examine the relationships among sanitation variables, water-related variables, and health outcomes, while accounting for demographic and socioeconomic factors. The study found that 3.3% of children under-five experienced diarrhoea within three months preceding the survey. Key factors associated with diarrheal prevalence included age, racial group, and poor handwashing practices. Logistic regression analysis revealed that handwashing practices were the strongest determinant. Handwashing after using the toilet was significantly associated with a reduced prevalence of diarrhoea. The study underscores the urgent need for health education initiatives that improve hand-washing practices to reduce diarrheal-related infections among under-five children in South Africa. Addressing poor sanitation practices and consumption of unimproved drinking water through targeted interventions could significantly lower diarrheal-related deaths and improve public health outcomes.

Despite being critical for improving student nutrition, there is limited evidence of food safety practices among food vendors around university settings. This cross-sectional study assessed food safety practices and associated factors among 322 food handlers using a modified Poisson regression model. We found out that 53.1% (171/326) of the food vendors exhibited poor food safety practices. Food handlers with a tertiary education (PR = 0.47, 95% CI: 0.34-0.98) and those having a valid food handlers license (PR = 0.47, 95% CI: 0.37 -0.61) were less likely to exhibit poor food safety practices. Food handlers working in a food establishment with adequate wholesome water (PR = 1.74, 95% CI: 1.16 - 2.60), agreeing that it is safe to leave food out of the refrigerator for more than 2 h (PR = 1.37, 95% CI 1.07-1.77) and disagreeing to a food handler using the same towel to clean various places (PR = 1.60, 95% CI: 1.14 - 2.23) predicted poor food safety practices. Factors associated with poor food safety practices included low levels of formal education, working in unlicensed food premises, and limited access to safe drinking water. There is an urgent need for comprehensive food safety training programs and stricter enforcement of food safety regulations in educational settings to improve food-handling practices.

Lung cancer remains the leading cause of cancer-related mortality worldwide, highlighting the urgent need for the development of novel therapeutic agents. Glycyrrhiza glabra, a medicinally significant plant, is known for its rich composition of diverse phytochemicals. However, its role in the induction of apoptosis in lung cancer cells has not been well elucidated. The present study aimed to evaluate the apoptosis-associated cytotoxic and antiproliferative effects of Glycyrrhiza glabra methanol extract (GGME) on non-small cell lung cancer (A549) cells. The viability of GGME-treated A549 cells was assessed using an MTT assay, which revealed a significant antiproliferative effect at 200 µg/ml (p < 0.05). Morphological changes were observed via phase-contrast inverted microscopy. To elucidate the mode of cell death, Annexin V/PI staining was performed, and the mRNA levels of the pro-apoptotic Bax and anti-apoptotic Bcl-2 genes were quantified by real-time PCR. Interestingly, while Bax expression increased 4-fold (p < 0.01) compared to the control, Bcl-2 levels remained unchanged. Despite this pro-apoptotic shift in gene expression, the cells predominantly underwent necrotic cell death rather than apoptosis. Furthermore, LC-MS/MS analysis identified vanillic acid, fumaric acid, syringic acid, and thymoquinone as the major compounds in GGME. In conclusion, GGME exerts a antiproliferative effect primarily through necrosis rather than apoptosis.

Wildfire events are increasing in frequency and intensity globally, partly due to climate change. This emerging public health crisis will disproportionately impact vulnerable populations such as children. Epidemiological studies link wildfire smoke, especially fine particulate matter (PM2.5 and PM10), with adverse respiratory outcomes; yet few focus specifically on pediatric populations. This systematic review examines wildfire smoke impacts respiratory health in youth populations by analyzing studies identified through a comprehensive literature search in PubMed and Web of Science through 30 September 2024. Of 120 publications identified, five met the inclusion criteria: three retrospective cohorts, one cross-sectional, and one case-crossover study. Studies were conducted in the U.S. and Canada, using various exposure assessment methods including stationary monitors, satellite imagery, and surveys. Not all studies reported compatible effect measures, vote counting based on the direction of effect, and statistical significance was applied. All studies reported increases in respiratory symptoms, hospital visits, and medication use on days with significant wildfire smoke exposure. Differences in exposure measurement methods, health outcome definitions, and age stratifications limited cross-study comparability. Despite limitations, the review found consistent evidence linking wildfire smoke exposure to worsened respiratory health in children. Further research using standardized exposure assessments and age-specific analyses is needed.

Nursery operators are potentially exposed to environmental contaminants, particularly toxic trace elements from prolonged agrochemical use. This study evaluated and compared trace element concentrations in hair and nail samples of nursery operators from conventional and organic nurseries in Peninsular Malaysia. A comparative cross-sectional study was conducted with 48 participants (20 from conventional and 28 from organic nurseries). Hair and nail samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to quantify 14 trace elements. Results showed that conventional nursery operators had significantly higher concentrations of toxic elements, including arsenic (As), cadmium (Cd), lead (Pb), and ammonia (NH₃), than their organic counterparts (p < 0.05). Correlation analysis between hair and nail matrices showed strong associations for magnesium, chromium, cobalt, and zinc, suggesting shared sources and possible co-exposure. Notably, synergistic accumulation patterns were observed among lead, arsenic, manganese, and mercury, while antagonistic interactions were evident between cadmium and essential elements such as zinc and chromium. These findings underscore heightened occupational health risks in conventional nursery environments due to cumulative trace element exposure, highlight the utility of hair and nail biomarkers for long-term exposure monitoring, and advocate for stricter agrochemical regulations and enhanced occupational safety practices.

Cockroaches are significant health hazards as they can carry and transmit various pathogens, leading to serious illnesses in humans. This study investigates the global prevalence of intestinal protozoan parasites (IPPs) in cockroaches through a systematic review and meta-analysis. Several databases, including (PubMed, Scopus, Web of Science, and Google Scholar), were searched for publications covering 2003 to 2024. Following PRISMA guidelines, we identified 5,955 records, resulting in 36 eligible studies. The pooled global prevalence of contaminated cockroaches was estimated at 0.26 (95% CI = 0.16-0.37). Further analysis indicated that the highest pooled prevalence based on sample source was found in zoo samples (0.82, 95% CI = 0.75-0.88). Polymerase Chain Reaction (PCR) detection methods yielded the highest prevalence (0.42, 95% CI = 0-1.00), while Blatta orientalis showed a pooled prevalence of 0.57 (95% CI = 0.49-0.65). Geographically, Asia exhibited the highest prevalence rate (0.35, 95% CI = 0.16-0.57), particularly in low-income countries (0.56, 95% CI = 0.00-1.00). These findings underscore significant public health concerns regarding the contamination of cockroaches with IPPs and highlight the necessity for effective monitoring and control measures.