Exposure to ambient air pollution has significant adverse health effects; however, whether air pollution is associated with urological cancer is largely unknown. We conduct a systematic review and meta-analysis with epidemiological studies, showing that a 5 μg/m³ increase in PM_2.5 exposure is associated with a 6%, 7%, and 9%, increased risk of overall urological, bladder, and kidney cancer, respectively; and a 10 μg/m³ increase in NO₂ is linked to a 3%, 4%, and 4% higher risk of overall urological, bladder, and prostate cancer, respectively. Were these associations to reflect causal relationships, lowering PM_2.5 levels to 5.8 μg/m³ could reduce the age-standardized rate of urological cancer by 1.5 ~ 27/100,000 across the 15 countries with the highest PM_2.5 level from the top 30 countries with the highest urological cancer burden. Implementing global health policies that can improve air quality could potentially reduce the risk of urologic cancer and alleviate its burden.

Introduction Asymptomatic infection of SARS-CoV-2 may lead to silent community transmission and compromise the COVID-19 pandemic control measures. We aimed to estimate the rate of asymptomatic COVID-19 from published studies and compare this rate among different regions and patient groups. Methods In this systematic review and meta-analysis, electronic databases including Medline, Embase, PubMed and three Chinese electronic databases (Chinese National Knowledge Infrastructure [CNKI], WanFang Data and China Science, and Technology Journal Database [VIP]) were searched for literature published from 1 November 2019 to 31 December 2020. Original investigations with sample size (or number of subjects) not less than five were included for further analyses. Subgroup analyses were conducted according to different study types, study periods, geographical regions and patient demographics. The STATA (V.14.0) command ‘metaprop’ was implemented to conduct a meta-analysis of the pooled rate estimates of asymptomatic infections with exact binomial and score test-based 95% confidence interval (CI). Results A total of 130 123 ascertained COVID-19 infections from 241 studies were included in this meta-analysis, including 31 411 asymptomatic infections. The overall rate of asymptomatic infections was 23.6% (18.5%–29.1%) and 21.7% (16.8%–27.0%) before and after excluding presymptomatic cases, respectively. Subgroup analysis showed that significantly higher in pregnant women (48.8%, 28.9%–68.9%), children (32.1%, 24.2%–40.5%), and studies reporting screening programmes (36.0%, 24.6%–48.1%) conducted on or after 1 March 2020 (42.5%, 33.4%–51.9%). In terms of geographical region, the rate was the highest in Africa (64.3%, 56.7%–71.6%), followed by America (40.0%, 27.4%–53.3%), Europe (28.1%, 19.0%–38.1%) and Asia (18.1%, 13.2%–23.5%). Conclusion We approximated that one-fifth of COVID-19 infections are asymptomatic throughout the course of infection. Public health policies targeting these high-risk groups may be recommended to achieve early identification and more stringent containment of the pandemic.

Some studies have examined the association between air pollution and semen quality. While it is less of evidence on the sperm quality after long-term air pollution exposure, especially the co-exposure of different air pollution components. Additionally, the role of DNA methylation in it hasn't been confirmed. This study aimed to investigate whether long-term exposure to air pollution was associated with semen quality, as well as to explore the effect of sperm DNA methylation in such association. From 2014 to 2016, 1607 fertile men were enrolled to evaluate 14 parameters of semen quality. Exposure window was defined as one-year before semen sampling. Multivariable linear regression and weighted quantile sum (WQS) regression model were used to investigate the association between six air pollutants co-exposure and semen quality. Sensitivity analysis regarding at the normal semen quality group was also conducted. Semen samples were randomly selected from 200 participants to detect the genomic 5-methylcytosine (5 mC) and 5-hydroxymethylcytosine (5-hmC) levels in sperm. In the total population, PM₁₀, PM_2.5, SO₂, and NO₂ were negatively associated with sperm total motility (PM₁₀: β = -2.67, P = 0.009; PM_2.5: β = -2.86, P = 0.004; SO₂: β = -2.32, P = 0.011; NO₂: β = -2.21, P = 0.012). Results of the normal semen quality group were consistent with those from the whole population. WQS regression results indicated significant decreasing sperm total motility after the co-exposure of the six air pollutants (β = -1.64, P = 0.003) in whole participants. Wherein, PM₁₀ accounted for largest proportion (43.4%). The 5-hmC level was positively associated with PM₁₀ exposure (β = 0.002, P < 0.001). Long-term exposure to PM₁₀, PM_2.5, SO₂, and NO₂, as well as co-exposure to six air pollutants, reduced semen quality in fertile men. As the most significant contributor of air pollutant, PM₁₀ exposure decreased sperm DNA methylation.

Knowledge gaps remain regarding the cardiorespiratory impacts of ambient volatile organic compounds (VOCs) for the general population. This study identified contributing sources to ambient VOCs and estimated the short-term effects of VOC apportioned sources on daily emergency hospital admissions for cardiorespiratory diseases in Hong Kong from 2011 to 2014. We estimated VOC source contributions using fourteen organic chemicals by positive matrix factorization. Then, we examined the associations between the short-term exposure to VOC apportioned sources and emergency hospital admissions for cause-specific cardiorespiratory diseases using generalized additive models with polynomial distributed lag models while controlling for meteorological and co-pollutant confounders. We identified six VOC sources: gasoline emissions, liquefied petroleum gas (LPG) usage, aged VOCs, architectural paints, household products, and biogenic emissions. We found that increased emergency hospital admissions for chronic obstructive pulmonary disease were positively linked to ambient VOCs from gasoline emissions (excess risk (ER%): 2.1%; 95% CI: 0.9% to 3.4%), architectural paints (ER%: 1.5%; 95% CI: 0.2% to 2.9%), and household products (ER%: 1.5%; 95% CI: 0.2% to 2.8%), but negatively associated with biogenic VOCs (ER%: −6.6%; 95% CI: −10.4% to −2.5%). Increased congestive heart failure admissions were positively related to VOCs from architectural paints and household products in cold seasons. This study suggested that source-specific VOCs might trigger the exacerbation of cardiorespiratory diseases.

In Xuan Wei, China, the lung cancer mortality rate is rising significantly more than that of the nation overall. However, it remains unclear 1) if improved diagnosis can just partially explain this observation and how other local risk factors may be correlated with the lung cancer mortality rate and 2) how the lung cancer mortality rates differ within Xuan Wei and how these spatiotemporal patterns are linked with local risk factors. To increase etiological knowledge, this study evaluated the spatial and temporal distributions of the health effects (the lung cancer mortality rates) from 2011 to 2015. Four steps of spatial analysis were applied, as follows: 1) hotspot analysis to determine the geographical patterns of lung cancer mortality, 2) spatially-weighted sum to identify areas with higher health risks, 3) bivariate statistical analysis to assess the overall correlation between coal mines and lung cancer mortality, and 4) geographically-weighted regression to test for correlations among different towns within Xuan Wei. Women had higher lung cancer mortality rates than those in men, with an increasing trend in both sexes over time. The incidence rates in Laibin Town were the highest in Xuan Wei every year. Over the 5-year study period, the lung cancer mortality was increasingly concentrated in Laibin, Shuanglong, and Longchang, where the smoky coal mines are most concentrated. The population-level health risks from the coal mine in Xuan Wei were mapped and divided into five types of risk areas (Type I – Type IV). Correlation analysis revealed that there was no significant correlation between lung cancer mortality as a whole and coal mine distribution during the 5-year study period. However, the geographically-weighted regression revealed a stronger correlation in medium (Type III) and second-lowest (Type IV) health risks. Xuan Wei lung cancer mortality has increased continuously since the third national retrospective surveys on the causes of death by the Ministry of Health of the People’s Republic of China (2004–2005), especially for local women and residents over 35 years of age. Geographically, lung cancer in Xuan Wei showed unique spatiotemporal clustering. The local lung cancer mortality was significantly correlated with the smoky coal mine geographically. Some specific towns (Laibin, Shuanglong, and Longchang) within Xuan Wei manifested high correlations between lung cancer mortality and coal mines. The effects of coal mines on lung cancer mortality rates also spread geographically outward from these areas. Public health concern regarding lung cancer in Xuan Wei should prioritize higher-risk towns surrounded by smoking coal mines. Intervention strategies for particular toxic coal types require further studies on their chemical characteristics and mechanisms of carcinogenesis. Additional studies are also warranted to systematically examine the local environmental health risks related to coal industries and combustion air pollution and eventually to conduct early screening of lung cancer for local people who are more exposed to smoky coal in high-risk areas.

Short-term exposure to fine particulate matter (PM_2.5) and its specific constituents might exacerbate allergic rhinitis (AR) conditions. However, the evidence is still inconclusive. We conducted a panel study of 49 patients diagnosed with AR > 1 year prior to the study in Taiyuan, China, to investigate associations of individual exposure to PM_2.5 and its constituents with oxidative parameters, symptoms, and quality of life among AR patients. All participants underwent repeated assessments of health and PM exposure at 4 time points in both the heating and nonheating seasons from June 2017 to January 2018. AR patients' oxidative parameters were assessed using nasal lavage, and their subjective symptoms and quality of life were determined through in-person interviews using a structured questionnaire. Short-term personal exposure to PM_2.5 and its constituents was estimated using the time-microenvironment-activity pattern and data from the nearest air sampler, respectively. We applied mixed-effects regression models to estimate the short-term effects of PM_2.5 and its constituents. The results showed that exposure to PM_2.5 and its constituents, including BaP, PAHs, SO₄^2-, NH₄⁺, V, Cr, Cu, As, Se, Cd, and Pb, was significantly associated with increased oxidative stress, as indicated by an increase in the malondialdehyde (MDA) index. Exposure to PM_2.5 and its components (V, Mn, Fe, Zn, As, and Se) was associated with decreased antioxidant activity, as indicated by a decrease in the superoxide dismutase (SOD) index. Additionally, increased visual analog scale (VAS) and rhinoconjunctivitis quality of life questionnaire (RQLQ) scores indicated that exposure to PM_2.5 and its constituents exacerbated inflammatory symptoms and affected quality of life in AR patients. Exposure to PM_2.5 and specific constituents, could exacerbate AR patients' inflammatory symptoms and adversely affect their quality of life in the heavily industrialized city of Taiyuan, China. These findings may have potential biological and policy implications.