Particulate matter (PM4) was collected from teachers' breathing zones during classroom lessons using GilAir 3 personal pumps attached to a cyclone (cut-point: PM4) connected to a 25 mm cassette housing a polyvinyl chloride membrane filter. Sampling was conducted at 1.85 L/min from Monday to Friday between 08:00 and 14:35. Sixty samples were collected from 12 teachers (seven females and five males). A multipath particle dosimetry model was used to predict particle deposition in teachers' respiratory tracts at low, moderate, and high exertion levels during nasal and oronasal breathing. PM4 concentrations ranged from 0.019 to 0.761 mg/m3, with an average of 0.126 ± 0.134 mg/m3. Chalk use (β = 0.468, p < 0.001) and sampling duration (β = 0.305, p < 0.001) were positively associated with PM4 concentrations. Breathing route was the main determinant of particle deposition, and the deposition varied by sex, respiratory region, and exertion level. Males exhibited greater deposited mass than females across all breathing routes and exertion levels. Particle clearance was slower in the alveolar region than in the tracheobronchial region in both sexes, allowing prolonged particle retention. Teachers may be at risk of developing respiratory disorders even when exposed to PM4 concentrations below the relevant occupational exposure limit.
This study analyzed the structure and distribution of airborne bacterial communities in a hospital environment to explore their potential relationship with hospital-acquired infections (HAIs). In summer and winter, a large-capacity total suspended particle (TSP) sampler was used to collect air microbial samples from 10 different hospital locations. DNA was extracted from the samples using a magnetic bead enrichment method followed by a rapid soil DNA extraction kit. Bacterial 16S rRNA gene amplicon sequencing was performed to characterize microbial taxa, and sequences related to potentially pathogenic bacteria were screened by alignment to reference databases. The outpatient hall showed the highest relative microbial richness among the sampled areas. Sequences assigned to potentially pathogenic bacteria accounted for 2.19% of all sequences. Seasonal variation was observed; sequences assigned to Pseudomonas aeruginosa and Escherichia coli were more abundant in summer, whereas sequences assigned to Streptococcus pneumoniae were more abundant in winter. These findings indicate that the complex airborne bacterial community in the hospital is influenced by location and season, highlighting the need for targeted infection prevention and air-quality management strategies. Because 16S rRNA gene amplicon sequencing has limited taxonomic resolution for some bacterial groups, species-level identification and pathogenicity inference should be interpreted with caution.
Antibiotic-resistant bacteria (ARB) and their associated antibiotic resistance genes (ARGs) represent a growing threat in clinical settings. ARB and ARGs from environmental ecosystems can persist in their native habitats and potentially transfer to human and animal pathogens. Aeromonas spp. has emerged as a notable nosocomial pathogen and is increasingly recognized as a bioindicator of antibiotic resistance in aquatic environments. Thus, Aeromonas spp. may play a pivotal role in the mobilization and dissemination of ARGs. This review synthesizes current literature on the presence and diversity of integrons, genetic elements that facilitate the horizontal transfer of resistance genes, within Aeromonas spp. isolated from aquatic ecosystems. Class 1 integrons are the most frequently reported in Aeromonas, although class 2 integrons have also been detected across various species and geographic regions. A substantial proportion of integron-positive Aeromonas isolates exhibit multidrug resistance (MDR). Moreover, diverse gene cassettes arrays have been identified in different Aeromonas strains, reflecting a high level of genetic variability. In conclusion, Aeromonas spp. represent a significant reservoir and vector for ARGs in aquatic systems, with the potential to transfer these resistance determinants to other pathogenic bacteria through drinking water and the food chain, thereby posing a public health risk.
Antimicrobial resistance (AMR) is a major global health threat, yet longitudinal surveillance data from Jordan remain limited. This retrospective multicenter surveillance study analyzed routinely collected electronic and laboratory records from 21 Jordanian hospitals between 2013 and 2023. Microbiology records were de-duplicated using a first-isolate-per-patient-per-organism-per-year rule. Among 873,124 bacterial isolates, Escherichia coli (65.3%) predominated, followed by Klebsiella pneumoniae (16.9%), Staphylococcus aureus (12.3%), and Pseudomonas aeruginosa (5.5%). E. coli was associated with female sex and community-acquired infection, whereas K. pneumoniae and P. aeruginosa were more common in hospital settings, with K. pneumoniae strongly associated with intensive care. Although overall odds of any resistance declined significantly over time, several clinically important phenotypes increased. Methicillin-resistant S. aureus rose from 60.0% to 75.9%, while carbapenem resistance reached 4.9% in E. coli, 20.4% in K. pneumoniae, and 19.2% in P. aeruginosa by 2023. Fluoroquinolone resistance also increased, and multidrug-resistant P. aeruginosa reached 20.6%. These findings highlight a distinct AMR paradox in Jordan and underscore the need for pathogen-specific empirical therapy, strengthened antimicrobial stewardship and infection prevention, and sustained national surveillance.
Household dust carries indoor bacteria, fungi, and mites. Endotoxin, a component of the cell wall of gram-negative bacteria, is a known important indoor toxic pollutant. To our knowledge, the association between household dust endotoxin and all-cause mortality risk has not been studied. Using data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 with mortality follow-up through 31 December 2019, we evaluated this association while adjusting for relevant covariates and performing mediation analyses. Elevated household dust endotoxin levels showed a significant linear association with all-cause mortality (P-overall = 0.015), an effect significantly modified by the poverty-income ratio (PIR). Given the established links between poverty and poor living conditions, we hypothesized that household dust endotoxin mediates the relationship between poverty and increased mortality risk. Mediation analysis confirmed a significant indirect effect, with household dust endotoxin accounting for 6.1% of the total effect of PIR on mortality (P for indirect effect = 0.01), a finding that remained robust in sensitivity analyses. These results indicate that household dust endotoxin not only increases all-cause mortality risk but also serves as a significant mediator in the pathway linking poverty to elevated mortality.
This study investigated the impacts and interactive effects of apparent temperature and air pollutants on rural pneumonia hospitalizations in Jiuquan, China (2015-2020), utilizing NRCMS surveillance data, distributed lag non-linear models (DLNM), and stratified analyses. The findings revealed an inverted U-shaped relationship between apparent temperature and pneumonia hospitalizations, peaking at a relative risk (RR) of 1.50 (95% CI: 1.41-1.60). Per interquartile range (IQR) increases in CO, SO2, O3, NO2, PM2.5, and PM10 were associated with RR values of 1.11 (95% CI: 1.01-1.21), 1.04 (95% CI: 0.97-1.12), 1.08 (95% CI: 0.93-1.24), 1.02 (95% CI: 0.93-1.12), 1.04 (95% CI: 0.97-1.12), and 1.05 (95% CI: 1.00-1.12), respectively. Furthermore, synergistic interactive effects occurred between low apparent temperature and high air pollution, and among distinct air pollutants. Subgroup analyses showed higher risks for children under 7 years old, minimal gender disparities, and more pronounced risks during autumn and winter. The study underscores the critical need for targeted interventions in rural areas during concurrent periods of low apparent temperature and high air pollution to reduce public health risks.
This study presents three artificial intelligence-based models - XGBoost, Random Forest (RF), and Deep Artificial Neural Network (DANN) - with 2-day lead time for forecasting broad-scale oyster norovirus outbreaks. Among them, the XGBoost model performs best and is characterized by unique features: (1) the model was constructed and tested with epidemiological and environmental data collected from three distinct coastal countries representing broad trends in oyster norovirus outbreaks; (2) model input variables include five important environmental predictors (along with their time-lags ranging from 2-30 days), identified by using Pearson correlation and Gini index, including solar radiation, water temperature, gage height, precipitation, and salinity plus GPS coordinates, which affect various processes governing the sources and sinks of oyster norovirus; and (3) the model output performance is characterized by a high accuracy, demonstrating the strongest overall prediction performance. This study identifies solar radiation and water temperature as the two most important predictors of oyster norovirus outbreaks. Another major finding is the strong long-range dependence of outbreaks on antecedent marine environmental conditions up to 30 days before. These novel features of the XGBoost model provide an effective early-warning framework that can support proactive management of oyster norovirus outbreaks.
Anthropogenic greenhouse gas emissions and urbanization have altered atmospheric conditions, increasing the frequency and intensity of extreme heat events. In response, Philadelphia issues a "Code-Red" heat health warning when temperatures exceed 95°F for three consecutive days. However, this threshold may be too high to protect vulnerable populations, including children with asthma. We conducted a case-crossover study to evaluate associations between heatwave intensity and duration and pediatric asthma exacerbations from March to August 2011-2016, in Philadelphia, PA. Exacerbations were identified using electronic health records from the Children's Hospital of Philadelphia. Conditional logistic regression models estimated associations, and we assessed effect modification by individual characteristics and neighborhood factors. Odds of asthma exacerbation were 15% higher following two consecutive days above the 95th percentile of daily maximum temperatures (93.5°F) compared to cooler days (OR: 1.15; 95% CI: 0.98-1.34). Estimates of associations were stronger among children aged 5-12 years (OR: 1.26; 95% CI: 0.97-1.63) and those living in racially and economically segregated neighborhoods (OR: 1.19; 95% CI: 1.00-1.42). These findings, though statistically insignificant, may suggest that local heat advisories could benefit from considering lower temperature thresholds and shorter duration criteria; however, additional studies are needed to further evaluate these associations.
High-altitude residence affects approximately 503 million people worldwide, yet its longitudinal impact on multimorbidity (coexistence of two or more self-reported, physician-diagnosed chronic conditions) remains poorly understood. Using four waves (2011-2018) of the China Health and Retirement Longitudinal Study (CHARLS), we examined 8,121 adults aged ≥45 years from prefectures classified as high altitude (≥1,500 m) or low altitude (<1,500 m). Generalized estimating equations (GEE) revealed a significant altitude-by-time interaction (odds ratio [OR]=1.033, 95% confidence interval [CI]: 1.006-1.060, P = 0.014), indicating a progressively faster rise in multimorbidity prevalence at high altitude over follow-up. Among the 3,852 baseline multimorbidity-free participants after 1:8 propensity score matching, Cox regression showed that high-altitude residence independently increased incident multimorbidity risk by 53.8% (hazard ratio [HR]=1.538, 95% CI: 1.343-1.761, P < 0.001). The association was consistent across all eight subgroups and multiple sensitivity analyses (HR range: 1.432-1.523). High altitude should be incorporated into chronic-disease risk assessment, and prevention policies in high-altitude regions should prioritize multimorbidity, emphasizing sustained monitoring of long-term residents.
Cancer is a multifactorial disease characterized by uncontrolled cell growth and remains a major global health challenge. Given the limitations of conventional therapies, naturally derived compounds such as naphthoquinones have attracted interest for their antitumor potential. This study evaluated the in vitro effects of β-isopropylfuran-1,2-naphthoquinone (NAF-Q69), a synthetic isolapachol derivative, on different cell lines (MRC-5 - human lung fibroblasts; HEPG2 - hepatocellular carcinoma; HeLa - cervical cancer; TOV - ovarian adenocarcinoma; MDA-MB - breast adenocarcinoma; and J82 - urothelial carcinoma) to assess its cytotoxic activity and cellular characteristics (clonogenic survival, migration, morphology, cell cycle, and reactive oxygen species \[ROS] production). NAF-Q69 showed significant dose-dependent cytotoxicity in all tumor lines, with IC50 values ranging from 10.29 µM (MDA-MB) to 18.65 µM (HEPG2). It decreased viability, inhibited colony formation, and impaired migration, particularly in TOV, HeLa, and HEPG2 cells. Morphological alterations were evident. The compound induced cell death, with increased sub-G1 populations, and promoted G2/M arrest. Moreover, NAF-Q69 markedly elevated ROS levels, implicating oxidative stress as a central mechanism. In conclusion, NAF-Q69 exhibits promising antitumor activity by inhibiting proliferation and migration, inducing cell death, and enhancing oxidative stress, supporting the potential of naphthoquinones in cancer therapy.
Experimental studies suggest that formaldehyde may disrupt reproductive and endocrine function, but human evidence remains limited. We examined the association between formaldehyde exposure, measured as hemoglobin adducts, and serum sex steroid hormones among children (6-11 years) and adolescents (12-19 years) participating in NHANES 2013-2016. Multivariable regression models were used to evaluate associations between formaldehyde and total testosterone (TT), estradiol (E2), sex hormone-binding globulin (SHBG), free testosterone, free estradiol (FE2), and the TT/E2 ratio. False discovery rate (FDR) correction was applied to account for multiple comparisons, and restricted cubic spline models were used to assess potential non-linear dose - response relationships. After FDR correction, significant associations were observed only among female adolescents. Each doubling of formaldehyde concentration was associated with lower E2 (-55.74%; 95% CI: -73.43, -26.24%) and a higher TT/E2 ratio (96.84%; 95% CI: 18.26, 227.61). Restricted cubic spline analyses supported non-linear dose - response relationships. Although inverse associations between formaldehyde and several sex steroid hormones were observed across age-sex groups, most did not remain significant after FDR correction. These findings suggest that formaldehyde exposure may be associated with altered sex steroid hormone profiles in female adolescents.
This pilot study aimed to investigate the relationship between prenatal exposure to PM2.5 components and birth weight, and the regulatory role of IGF2 P2 promoter methylation in umbilical cord blood. In this pilot study of 527 mother-infant pairs from Henan Province, we assessed prenatal PM2.5 exposure using high-resolution air pollution data and evaluated its associations with IGF2 P2 promoter methylation and birth weight through multivariable regression, restricted cubic spline, and threshold effect analyses. Exposure to PM2.5 components including sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), organic matter (OM), and black carbon (BC) was associated with reduced birth weight (p < 0.05, β = -94.31 to -4.80 g). This relationship was more pronounced when the concentrations of PM2.5, BC, and OM exceeded 108.76, 4.93, and 26.43 μg/m3, respectively. The season of conception may influence pregnant women's susceptibility to PM2.5 exposure. Notably, the impact of PM2.5 components on birth weight was observed in neonates with hypomethylation of the IGF2 P2 promoter. PM2.5 components could lead to reduced birth weight, and hypomethylation of the IGF2 P2 promoter may be a danger signal. Effective preventive strategies include planning conception during the warm season and minimizing exposure to high concentrations of PM2.5.
Rodents are the most diversified mammals in the world and also serve as reservoirs of many pathogens of public health importance. The objective of this study is to examine the distribution and abundance of rodents and shrews and their ectoparasites in different ecological settings viz. rural, urban, coastal, and agricultural areas in the Karaikal region of Puducherry Union Territory, India. Standard methodology was used to capture the rodents and shrews and to collect the ectoparasites. The study revealed that the highest number of rodents and shrews were encountered in the urban ecosystem (36.7%). Among the rodents and shrews, Suncus murinus (Asian house shrew) captured from different ecosystems was the highest in number (42.2%) than rodents. Among the different ectoparasites collected, the percentage of trombiculid mites was high (83.2%). Plague vectors Xenopsylla cheopis and X. astia (12.6%), ticks, and lice (below 5%) were also recorded. The highest prevalence of trombiculid mites and plague fleas in the Karaikal region of Puducherry Union Territory warrants continuous surveillance to prevent ectoparasite-borne diseases.
Ambient aerosol pollution during pregnancy has been linked to adverse neonatal outcomes, but the relative importance of exposure timing versus intensity remains uncertain. This study investigated associations between maternal ambient aerosol exposure and neonatal cord blood hepatic enzyme activities among 92 newborns in Ahvaz, Iran, a city with severe particulate pollution. MODIS AOD data were used to estimate exposure across all gestational months. Cord blood biomarkers measured included ALT (21.1 ± 9.7 µ/l), AST (29.4 ± 11.3 µ/l), ALP (473.2 ± 105.8 µ/l), and GGT (147.9 ± 103.8 µ/l). Principal Component Analysis and Generalized Linear Models, adjusted for maternal age and infant sex, showed that cumulative exposure (PC1, 48.23% variance) and peak aerosol events (PC2, 13.58% variance) significantly increased several biomarkers (ALT: β = 0.631, p = 0.004; GGT: β = 6.996, p < 0.001). AST was marginally associated with cumulative exposure and significantly related to maternal age. Infant sex influenced GGT levels, while trimester-specific exposure showed limited effects. Overall, cumulative and peak aerosol exposures were found as the primary exposure patterns associated with altered neonatal cord blood hepatic enzyme activities, underscoring the need to reduce sustained and high-intensity pollution to protect fetal health.
This study aimed to assess fluoride exposure among school-aged children in endemic fluorosis areas of Jiangsu Province and to examine the relationships between urinary fluoride (UF), hair fluoride (HF), and dental fluorosis. In total, 320 children (aged 8-12) from two affected counties were included and divided into dental fluorosis (n = 140) and non-fluorosis (n = 180) groups. Spot urine and hair samples were collected. Dental fluorosis was diagnosed according to national standards (WS/T 208-2011). UF and HF were determined using standard methods (WS/T 89-2015; DZ/T 0253.4-2014). Generalized linear and logistic regression models were used for analysis. Median UF levels were 1.41 mg/L in the fluorosis group and 1.02 mg/L in the non-fluorosis group; median HF levels were 11.9 mg/kg and 11.5 mg/kg, respectively. HF was positively correlated with UF in both groups (non-fluorosis: β = 0.70, 95% CI: 0.17-1.23; fluorosis: β = 1.63, 95% CI: 0.69-2.56). Elevated UF (OR = 1.80, 95% CI: 1.35-2.40) and HF (OR = 1.27, 95% CI: 1.01-1.50) were significantly associated with higher odds of dental fluorosis. These findings indicate that both UF and HF are moderately predictive and limited discriminatory power biomarkers of internal fluoride exposure and are positively associated with dental fluorosis in children from endemic areas.
This study aimed to project heat- and cold-related respiratory morbidity throughout the 21st century. The baseline impact of heat and cold was estimated using a semi-parametric model, including an exposure metric derived from remote-sensing and monitoring station data. Attributable fractions (AFs) of respiratory morbidity were estimated from 2020 to 2100, accounting for adaptation (30%) and population fertility scenarios (low and high). We also projected the effect estimates by adjusting for greenness (NDVI) in the modeling process. Cold-related AFs were higher than heat-related AFs under all scenarios, however the cold effect declined, while the heat effect increased throughout the century, particularly under RCP8.5. The cold-related AF was statistically significant in 2020-2029 (AFRCP2.6: 46.8%; 95% CI: 0.91, 60.29, AFRCP4.5: 47.01%; 95% CI: 2.56, 59.4, AFRCP8.5: 46.62%; 95% CI: 0.93, 59.97), while there was big uncertainty in other decades and for heat-related estimates. Accounting for adaptation substantially reduced both heat and cold-related AFs, with a higher reduction for cold. Adjustment for greenness slightly reduced the uncertainty of cold-related estimates. Overall, climate change is likely to shift the burden of respiratory morbidity from cold -related to heat-related extremes in future. Adaptation measures and urban greening strategies should be considered when developing climate-related health adaptation plans.
Acrylamide (ACR), a potential neurotoxin, is produced during industrial and food processing. The mechanisms of ACR neurotoxicity are still under debate, and effective strategies need to be investigated. We examined the neuroprotective potential of losartan (LOS), an antihypertensive drug, against ACR-induced neurotoxicity. PC12 cells were treated with concentrations of LOS (10, 20, and 50 μM) for 24 h and then exposed to ACR (5 mM) for a further 24 h. Antioxidant markers (SOD and CAT) and oxidative damage markers (ROS and TBARS) were measured. Real-time PCR was used to examine the mRNA expression of Bax and Bcl-2. Western blotting was used to evaluate the protein expression of Nrf2, Keap1, HO-1, as well as total and cleaved caspase-3. Exposure to ACR caused a significant increase in ROS and TBARS levels and reduced activities of SOD and CAT. Exposure to ACR affected the mRNA expression of key apoptotic regulators Bax and Bcl-2, resulting in a higher Bax/Bcl-2 expression. Furthermore, ACR elevated the protein expression of total and cleaved caspase-3 and Nrf2, while decreasing Keap1 levels. ACR-induced changes were reversed by LOS treatment. The findings demonstrated that LOS can protect PC12 cells from ACR-induced neurotoxicity by enhancing antioxidant defenses and modulating apoptotic signaling.
