The relation between pesticides exposure and metabolic syndrome (MetS) has not been clearly identified. Performing a systematic review and meta-analysis, PubMed, Cochrane Library, Embase, and ScienceDirect were searched for studies reporting the risk of MetS following pesticides exposure and their contaminants. We included 12 studies for a total of 6789 participants, in which 1981 (29.1%) had a MetS. Overall exposure to pesticides and their contaminants increased the risk of MetS by 30% (95CI 22%–37%). Overall organochlorine increased the risk of MetS by 23% (14–32%), as well as for most types of organochlorines: hexachlorocyclohexane increased the risk by 53% (28–78%), hexachlorobenzene by 40% (0.01–80%), dichlorodiphenyldichloroethylene by 22% (9–34%), dichlorodiphenyltrichloroethane by 28% (5–50%), oxychlordane by 24% (1–47%), and transnonchlor by 35% (19–52%). Sensitivity analyses confirmed that overall exposure to pesticides and their contaminants increased the risk by 46% (35–56%) using crude data or by 19% (10–29%) using fully-adjusted model. The risk for overall pesticides and types of pesticides was also significant with crude data but only for hexachlorocyclohexane (36% risk increase, 17–55%) and transnonchlor (25% risk increase, 3–48%) with fully-adjusted models. Metaregressions demonstrated that hexachlorocyclohexane increased the risk of MetS in comparison to most other pesticides. The risk increased for more recent periods (Coefficient = 0.28, 95CI 0.20 to 0.37, by year). We demonstrated an inverse relationship with body mass index and male gender. In conclusion, pesticides exposure is a major risk factor for MetS. Besides organochlorine exposure, data are lacking for other types of pesticides. The risk increased with time, reflecting a probable increase of the use of pesticides worldwide. The inverse relationship with body mass index may signify a stockage of pesticides and contaminants in fat tissue.

Individual-level studies with adjustment for important COVID-19 risk factors suggest positive associations of long-term air pollution exposure (particulate matter and nitrogen dioxide) with COVID-19 infection, hospitalisations and mortality. The evidence, however, remains limited and mechanisms unclear. We aimed to investigate these associations within UK Biobank, and to examine the role of underlying chronic disease as a potential mechanism. UK Biobank COVID-19 positive laboratory test results were ascertained via Public Health England and general practitioner record linkage, COVID-19 hospitalisations via Hospital Episode Statistics, and COVID-19 mortality via Office for National Statistics mortality records from March–December 2020. We used annual average outdoor air pollution modelled at 2010 residential addresses of UK Biobank participants who resided in England (n = 424,721). We obtained important COVID-19 risk factors from baseline UK Biobank questionnaire responses (2006–2010) and general practitioner record linkage. We used logistic regression models to assess associations of air pollution with COVID-19 outcomes, adjusted for relevant confounders, and conducted sensitivity analyses. We found positive associations of fine particulate matter (PM₂.₅) and nitrogen dioxide (NO₂) with COVID-19 positive test result after adjustment for confounders and COVID-19 risk factors, with odds ratios of 1.05 (95% confidence intervals (CI) = 1.02, 1.08), and 1.05 (95% CI = 1.01, 1.08), respectively. PM 2.5 and NO 2 were positively associated with COVID-19 hospitalisations and deaths in minimally adjusted models, but not in fully adjusted models. No associations for PM₁₀ were found. In analyses with additional adjustment for pre-existing chronic disease, effect estimates were not substantially attenuated, indicating that underlying chronic disease may not fully explain associations. We found some evidence that long-term exposure to PM₂.₅ and NO₂ was associated with a COVID-19 positive test result in UK Biobank, though not with COVID-19 hospitalisations or deaths.

The prevalence and transmission of antibiotic resistance genes (ARGs) and opportunistic pathogens in water environments can pose great threat to public health. However, the dissemination of ARGs and opportunistic pathogens from water environments to humans has been poorly explored. Here, we employed 16S rRNA gene sequencing and high-throughput quantitative PCR techniques to explore the seasonal distribution of ARGs and opportunistic pathogens in the Yellow River water (source water) and tap water, as well as their relationships with healthy humans at Lanzhou, China. Physiochemical analysis was applied to detect water quality parameters and heavy metal contents. The absolute abundance and diversity of ARGs in the Yellow River and tap water demonstrated distinct seasonal patterns. In winter, the Yellow river water had the highest ARG abundance and diversity, while tap water owned the lowest. Mobile genetic elements (MGEs) were the predominant driver of ARG profiles in both the Yellow river and tap water. Null model analysis showed that ARG assembly in the Yellow River was more influenced by stochastic processes than tap water and this was independent of seasons. Total organic carbon and arsenic contents exhibited positive correlations with many ARGs. Opportunistic pathogens Aeromonas and Pseudomonas may be potential hosts for ARGs. Approximately 80% of detected ARGs were shared between water samples and the human gut. These persistent ARGs could not be entirely eliminated through drinking water treatment processes. Thus, it is crucial to protect sources of tap water from anthropogenic pollution and improve water treatment technologies to reduce the dissemination of ARGs and ensure drinking-water biosafety for human health.

Mangroves play a vital role in protecting the coastal community from the climate change effect and in the restoration of the coastal ecosystem. This research has been designed to determine the spatial and seasonal changes of potentially toxic elements’ (PTEs) concentration in sediments and their potential source contribution among the different human-driven processes in Sundarbans, Bangladesh. Different pollution evaluation indices, random forest (RF) model, conditional inference tree (CIT), self-organizing map (SOM), geographical information system (GIS), and principal component analysis (PCA) were used for the interpretation of sources and risk assessment of PTEs. The mean concentration of PTEs both in winter and monsoon seasons has fallen below the threshold effect level but exceeded the rare effect level of marine sediments quality standards. Results showed that the PTEs were significantly enriched (EF > 1.00 < 70.00) in sediments, whereas the Cd enrichment (7.00% samples) was very alarming (EF = 60–70). Except for Zn and Cd, other PTEs were enriched in 30–60% samples. The highest geoaccumulation and contamination factors for Cd were observed in 46–72% of samples. The ecological risk (ER) factors showed similar results where Cd showed strong to very strong factors (ER = 110–2218) in 80% of samples. The CIT explained the natural/geogenic and anthropogenic sources of pollution, where the higher CIT values for Cd indicated industrial, aquaculture, and coal-based thermal powerplant. The RF model provided that shrimp firms, power plants, industry, and seaport were recognized as the influential sources for Zn, Pb, Cr, Cd, and As in sediments. Though Pb and As were found as the most significant pollutants, Cd was identified as a severe threat to ecology and public health. Based on CIT, RF, SOM and PCA the order of PTEs in mangroves sediment were:industrial/urban > aquaculture/shrimpfirm > powerplant > seaportoperation > tourism > geogenic/natural. The present study will help the policymakers for effective and sustainable management of the mangrove ecosystem.

Previous studies have indicated that outdoor light at night (LAN) is associated with a higher prevalence of overweight or obesity in adults. However, the association of LAN levels with overweight or obesity in children is still unknown. This study utilized data from the Seven Northeastern Cities study, which included 47,990 school-aged children and adolescents (ages 6–18 years). Outdoor LAN levels were measured using satellite imaging data. Weight and height were used to calculate age-sex-specific body mass index (BMI) Z-scores based on the World Health Organization (WHO) growth standards. Overweight status and obesity were defined using the Chinese standard. Information regarding socioeconomic status, sleep-related characteristics, and obesogenic factors were obtained using a questionnaire. A generalized linear mixed model examined the associations of outdoor LAN levels (in quartiles) with the outcomes of interest. Compared to children in the lowest quartile of outdoor LAN levels, children exposed to higher outdoor LAN levels had larger BMI Z-scores and higher odds of being overweight (including obesity) or obese, with the largest estimates in the third quartile [BMI Z-score: β = 0.26, 95% CI: 0.18–0.33; overweight (including obesity): OR = 1.40, 95% CI: 1.25–1.56; obesity: OR = 1.46, 95% CI: 1.29–1.65]. There was a significant sex difference (Pᵢₙₜₑᵣₐcₜᵢₒₙ<0.001) in the association of outdoor LAN levels with BMI Z-scores, and the association was stronger in males. Results remained robust following multiple sensitivity analyses and the adjustment of sleep-related characteristics, obesogenic factors, and environmental exposures. Our findings suggest that higher outdoor LAN levels are associated with larger BMI Z-scores and greater odds of overweight (including obesity) and obesity in school-aged children and adolescents. Further, the association between outdoor LAN levels and BMI Z-scores is stronger in males. Future studies with exposure assessments that consider both outdoor and indoor LAN exposures are needed.

Excessive exposure to light at night (LAN) has become a serious public health concern. However, little is known about the impact of indoor LAN exposure on blood pressure, particularly among young adults. We aimed to investigate the effects of bedroom individual-level LAN exposure in real-world environment on blood pressure and hypertension among vulnerable young adults, and to evaluate the possible buffering effect of physical activity. In this cross-sectional study, a total of 400 healthy young adults aged 16–22 years were included. Bedroom LAN exposure was recorded at 1-min intervals for two consecutive nights using a TES-1339 R illuminance meter. Blood pressure was measured three times (8–11 a.m. in the physical examination day) in the seated position using an Omron HEM-7121 digital sphygmomanometer. A wrist-worn triaxial accelerometer (ActiGraph GT3X-BT) was used to assess physical activity for seven consecutive days. Each 1 lx increase of bedroom LAN intensity was associated with 0.55 mmHg-increase in SBP (95% CI: 0.15, 0.95), 0.30 mmHg-increase in DBP (95% CI: 0.06, 0.54), and 0.38 mmHg-increase in MAP (95% CI: 0.12, 0.65). Higher levels of LAN exposure were associated with increased risk of hypertension (LAN ≥ 3lx vs. LAN < 3lx: OR = 3.30, 95%CI = 1.19–9.19; LAN ≥ 5lx vs. LAN < 5lx: OR = 3.87, 95%CI = 1.37–10.98). However, these detrimental effects of bedroom LAN exposure on blood pressure and hypertension were not observed among young adults with high MVPA (≥2 h/day) level. MVPA can alleviate negative effects of bedroom LAN exposure on blood pressure and hypertension. Maintaining bedroom settings darkness at night may be an important strategy for reducing the risk of hypertension. Furthermore, for individuals living with high levels of indoor LAN exposure, regular physical activity may be a good option for preventing cardiovascular disease and hypertension.

The health risks to populations induced by lead (Pb) and high-fat diets (HFD) have become a global public health problem. Pb and HFD often co-exist and are co-occurring risk factors for cognitive impairment. This study investigates effect of combined Pb and HFD on cognitive function, and explores the underlying mechanisms in terms of regulatory components of synaptic plasticity and insulin signaling pathway. We showed that the co-exposure of Pb and HFD further increased blood Pb levels, caused body weight loss and dyslipidemia. The results from Morris water maze (MWM) test and Nissl staining disclosed that Pb and HFD each contributed to cognitive deficits and neuronal damage and combined exposure enhanced this toxic injury. Pb and HFD decreased the levels of synapsin-1, GAP-43 and PSD-95 protein related to synaptic properties and SIRT1, NMDARs, phosphorylated CREB and BDNF related to synaptic plasticity regulatory, and these decreases was greater when combined exposure. Additionally, we revealed that Pb and HFD promoted IRS-1 phosphorylation and subsequently reduced downstream PI3K-Akt kinases phosphorylation in hippocampus and cortex of rats, and this process was aggravated when co-exposure. Collectively, our data suggested that combined exposure of Pb and HFD enhanced cognitive deficits, pointing to additive effects in rats than the individual stress effects related to multiple signaling pathways with CREB-BDNF signaling as the hub. This study emphasizes the need to evaluate the effects of mixed exposures on brain function in realistic environment and to better inform prevention of neurological disorders via modulating central pathway, such as CREB/BDNF signaling.

Urban green spaces (UGSs) are often positively associated with the health of urban residents. However, UGSs may also have adverse health effects by releasing biogenic volatile organic compounds (BVOCs) and increasing the ambient concentrations of ozone (O₃) and secondary organic aerosols in urban areas. BVOC emissions from UGSs might be underestimated because of the lack of consideration of the UGS land-use type in urban areas. As such, in this study, we used a newly released satellite dataset, Sentinel-2, with a resolution of 10 m, to derive the classification distribution of UGSs and predict the UGS emissions of BVOCs in Beijing in 2019. The results showed that the annual emissions of BVOCs from UGSs were approximately 2.9 Gg C (95% confidence interval (CI): 2.4–3.3) in the six core districts, accounting for approximately 39% of the total UGS emissions in Beijing. Compared with the results based on Sentinel-2, the BVOC emissions might be underestimated by approximately 37% (95% CI: 11–63) using the commonly used satellite dataset. UGSs produced the highest BVOC emissions in summer (from June to August), accounting for 75.2% of the annual emissions. UGSs contributed the most to the O₃ formation potential in summer, accounting for 41.5% of the total. We could attribute a considerable amount of the O₃ concentration (27.0 μg m⁻³, 95% CI: 21.4–32.6) to the UGS BVOCs produced in the core districts of Beijing in July. The new BVOC emissions dataset based on Sentinel-2 vegetation information facilitates modeling studies on the formation of surface O₃ in urban areas and assessments of the impact of UGSs on public health.

Air pollution and extreme heat have been responsible for more than a million deaths in China every year, especially in densely urbanized regions. While previous studies intensively evaluated air pollution episodes and extreme heat events, a limited number of studies comprehensively assessed atmospheric hot-and-polluted-episodes (HPE) – an episode with simultaneously high levels of air pollution and temperature – which have potential adverse synergic impacts on human health. This study focused on the Pearl River Delta (PRD) region of China due to its high temperature in summer and poor air quality throughout a year. We employed geostatistical downscaling to model meteorology at a spatial resolution of 1 km, and applied a machine learning algorithm (XGBoost) to estimate a high-resolution (1 km) daily concentration of particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅) and ozone (O₃) for June to October over 20 years (2000–2019). Our results indicate an increasing trend (∼50%) in the frequency of HPE occurrence in the first decade (2000–2010). Conversely, the annual frequency of HPE occurrence reduced (16.7%), but its intensity increased during the second decade (2010–2019). The northern cities in the PRD region had higher levels of PM₂.₅ and O₃ than their southern counterparts. During HPEs, regional daily PM₂.₅ exceeded the World Health Organization (WHO) and Chinese guideline levels by 75% and 25%, respectively, while the O₃ exceeded the WHO O₃ standard by up to 69%. Overall, 567,063 (95% confidence interval (CI): 510,357–623,770) and 52,231 (95%CI: 26,116–78,346) excessive deaths were respectively attributable to exposure to PM₂.₅ and O₃ in the PRD region. Our findings imply the necessity and urgency to formulate co-benefit policies to mitigate the region's air pollution and heat problems.

Particulate-filtering respirators (PFRs) have been recommended as a practical personal-level intervention to protect individuals from the health effects of particulate matter exposure. However, the cardiovascular benefits of PFRs including improvements in key surrogate endpoints remain unclear. We performed a systematic review and meta-analysis of randomized studies (wearing versus not wearing PFRs) reporting the effects on blood pressure (BP) and heart rate variability (HRV). The search was performed on January 3, 2022 to identify published papers until this date. We queried three English databases, including PubMed, Web of Science Core Collection and Scopus. Of 527 articles identified, eight trials enrolling 312 participants (mean age ± standard deviation: 36 ± 19.8; 132 female) met our inclusion criteria for analyses. Study participants wore PFRs from 2 to 48 h during intervention periods. Wearing PFRs was associated with a non-significant pooled mean difference of −0.78 mmHg (95% confidence interval [CI]: −2.06, 0.50) and −0.49 mmHg (95%CI: −1.37, 0.38) in systolic and diastolic BP (SBP and DBP). There was a marginally significant reduction of mean arterial pressure (MAP) by nearly 1.1 mmHg (95%CI: −2.13, 0.01). The use of PFRs was associated with a significant increase of 38.92 ms² (95%CI: 1.07, 76.77) in pooled mean high frequency (power in the high frequency band (0.15–0.4 Hz)) and a reduction in the low (power in the low frequency band (0.04–0.15Hz))-to-high frequency ratio [−0.14 (95%CI: −0.27, 0.00)]. Other HRV indices were not significantly changed. Our meta-analysis demonstrates modest or non-significant improvements in BP and many HRV parameters from wearing PFRs over brief periods. However, these findings are limited by the small number of trials as well as variations in experimental designs and durations. Given the mounting global public health threat posed by air pollution, larger-scale trials are warranted to elucidate more conclusively the potential health benefits of PFRs.