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Evidence concerning associations of per- and polyfluoroalkyl substances (PFASs) exposure with bone mineral density (BMD) and osteoporosis is scarce. Additionally, no study has examined the effects of PFAS isomers and alternatives on bone health.To evaluate the associations of PFASs and PFAS alternatives with BMD levels and osteoporosis prevalence.A total of 1260 healthy adults from southern China were enrolled. Serum concentrations of 32 legacy PFASs, PFAS isomers, and alternatives were measured using modified liquid chromatography-tandem mass spectrometry. Logistic and linear regression models were applied to evaluate the associations of PFASs with osteoporosis prevalence and BMD levels, respectively, adjusting for confounding factors. We performed stratified analyses to assess potential effect modifications of age and sex. We further used sensitivity analyses to testify the robustness of the main findings.There were 204 (16.2 %) participants diagnosed with osteoporosis. Eleven of the studied PFASs (i.e., PFHpA, PFOA, PFBS, PFHpS, total-PFHxS, n-PFHxS, br-PFHxS, br-PFOS, 1m-PFOS, Σ3 + 4 + 5m-PFOS, and 6:2 Cl-PFESA) showed significant and inverse associations with BMD levels (mean differences ranged from -6.47 to -26.07 per one ln-unit increase in the PFASs). Additionally, we observed that each one ln-unit increase in PFHpA was significantly associated a 23 % (OR = 1.23, 95 % CI = 1.04, 1.45) greater odds of osteoporosis. The above associations were consistent in several sensitivity analyses we performed. Stratified analyses showed stronger associations among women and younger compared to their counterparts.Our findings suggested that greater PFAS exposure is associated with poorer bone health, especially in women and younger people.

BACKGROUND: The role of fecal aerosols in the transmission of severe acute respiratory syndrome coronavirus 2 has been suspected. OBJECTIVE: To investigate the temporal and spatial distributions of 3 infected families in a high-rise apartment building and examine the associated environment variables to verify the role of fecal aerosols. DESIGN: Epidemiologic survey and quantitative reverse transcriptase polymerase chain reaction analyses on throat swabs from the participants; 237 surface and air samples from 11 of the 83 flats in the building, public areas, and building drainage systems; and tracer gas released into bathrooms as a surrogate for virus-laden aerosols in the drainage system. SETTING: A high-rise apartment building in Guangzhou, China. PARTICIPANTS: 9 infected patients, 193 other residents of the building, and 24 members of the building's management staff. MEASUREMENTS: Locations of infected flats and positive environmental samples, and spread of virus-laden aerosols. RESULTS: 9 infected patients in 3 families were identified. The first family had a history of travel to the coronavirus disease 2019 (COVID-19) epicenter Wuhan, whereas the other 2 families had no travel history and a later onset of symptoms. No evidence was found for transmission via the elevator or elsewhere. The families lived in 3 vertically aligned flats connected by drainage pipes in the master bathrooms. Both the observed infections and the locations of positive environmental samples are consistent with the vertical spread of virus-laden aerosols via these stacks and vents. LIMITATION: Inability to determine whether the water seals were dried out in the flats of the infected families. CONCLUSION: On the basis of circumstantial evidence, fecal aerosol transmission may have caused the community outbreak of COVID-19 in this high-rise building. PRIMARY FUNDING SOURCE: Key-Area Research and Development Program of Guangdong Province and the Research Grants Council of Hong Kong.

Background Evidence of association of ambient air pollution with cause-specific emergency department visits in China is still limited. This study aimed to investigate short-term associations between exposures to air pollutants and daily cause-specific emergency department visits using a large-scale multicenter database involving a total of 65 sentinel hospitals in Guangzhou, the most densely-populated city in south China, during 2013–2015. Material and methods We obtained data on 162,771 emergency department visits from 65 hospitals from the Emergency Medical Command Center in Guangzhou between January 1, 2013 and December 31, 2015. Daily air pollution data on particulate matter (PM) of aerodynamic diameter 10 , and PM 2.5 , respectively), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and ozone (O 3 ) were collected from the Daily Quality Report of the Guangzhou Environmental Protection Bureau during the study period. Visits for neurologic, respiratory and circulatory diseases were assessed in relation to air pollutants using Poisson generalized additive models. Results Mean daily number of emergency department visits for neurologic, respiratory and circulatory diseases was 89, 24 and 35, respectively. After adjustment for other pollutants (PM 2.5 , PM 10 , NO 2 and O 3 ), meteorological factors and time-varying confounders, a 7.98-μg/m 3 (interquartile range) increment in 2-day moving average of same-day and previous-day SO 2 concentrations was associated with the statistically significant increase of 4.89% (95% confidence interval: 2.86, 6.95) in neurologic emergency department visits; elevation in SO 2 level (per 7.98 μg/m 3 ) was linked to a 5.19% (95% confidence interval: 2.03, 8.44) increase in circulatory emergency department visits. Most positive links were seen during the cold season. Conclusions The results of this study contribute to the evidence of the significant associations between SO 2 and specific neurologic and circulatory conditions, and also provide insight into the planning of clinical services and emergency contingency response for air pollution exposures in Guangzhou.

Elevated blood homocysteine (Hcy) is an independent risk factor for cardiovascular disease. A growing number of studies have evaluated the link between air pollution and blood Hcy levels, but the results are inconsistent. To date, no systematic review of the published studies has been conducted yet. We aimed to provide a comprehensive overview of these studies. We systematically searched three international databases (PubMed, Web of Science, and Embase) and four Chinese databases (Wanfang, CNKI, CBM, and VIP) for peer-reviewed epidemiological studies investigating associations between ambient air pollutants and Hcy levels published before December 2019. We screened literature, extracted data, assessed methodological quality, and evaluated the risk of bias of the included studies. Of 1157 identified articles, 10 were finally included in this systematic review. Most were cross-sectional studies and were performed in developed countries. Particulate matter with aerodynamic diameters less than 2.5 μm (PM2.5) and/or 10 μm (PM10) were investigated in all of the included studies.. Overall, the evidence generally supports a positive association between higher PM concentrations and elevated Hcy levels. However, high heterogeneity in terms of study participants, study design, exposure duration, and particle components and sources, low methodological quality and probable high risk of bias in some studies, and limited literature number precluded us from drawing a robust conclusion. Associations between Hcy and gaseous pollutants were explored in only one or two studies, and the results were inconclusive. Additional, well-designed studies remain required to validate the association between air pollution and Hcy.

The magnitudes of toxicities and effects of the ambient concentration of total mass (weight) of particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) on adverse health outcomes manifest regional- and temporal-specific heterogeneity due to the variability of embedded chemical components. To explore acute hazards of 39 chemical components of PM2.5 on cause-specific emergency department visits (EDVs) in the Guangzhou, China, we firstly applied geographical detector method to quantify the individual and interactive effects of PM2.5 chemical components on the variability of EDVs. Then, a causal inference framework based on the Bayesian Additive Regression Trees (BART) was developed to estimate the causal impacts that would have had on cause-specific EDVs, under an assumptive intervention via setting median concentration of as the predefined threshold for each PM2.5 component. We found that the pairwise interactions of components play a more important role in explaining the variability of cause-specific EDVs than single factor separately. PM2.5 chemical components combined with gaseous pollutants as well as meteorological factors affect cause-specific diseases. We obtained robust causal estimates that exposures to high levels of vanadium and fluoranthene caused an increase in EDVs for neurological diseases (4.39%; 95% CI: 0.65%, 8.23%) and circulatory diseases (4.72%; 95% CI: 0.12%, 9.63%), respectively. A comprehensive strategy to reduce the hazards of toxic chemical components of PM2.5 is urgently needed.

Background At present, there are few studies on the effect of short-term interactions between ambient air pollutants and temperature on cause-specific emergency department visits in China. This study aimed to explore their short-term interactions on cause-specific emergency department visits using data collected from a total of 65 public hospitals in Guangzhou city, south China. Material and methods We included a total of 226,443 emergency department visits which were diagnosed as neurological, respiratory and circulatory disease in Guangzhou from January 1, 2014 to December 31, 2017. Average daily concentrations of air pollutants including carbon monoxide (CO), particulate matter having a median diameter of 2.5 μm or less (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) were collected from the Guangzhou Environmental Protection Bureau. We employed quasi-Poisson varying coefficient regression models to assess the interaction effects between air pollutants and daily temperature levels (DTLs) on emergency department visits for neurological, respiratory and circulatory diseases, respectively. Results Average number of emergency department visits for neurological, respiratory and circulatory diseases were 92, 26 and 38, respectively. After controlling for other pollutants, meteorological factors and other time-varying confounders, we found the interactions between NO2 and the 1st DTL (3.4–17.1 °C), NO2 and the 2nd DTL (17.1–23.5 °C) for neurological emergency department visits were statistically significant, displaying a nonlinear relationship. Additionally, we found that the interactions between SO2 and the 4th DTL (27.4–31.1 °C) also had a significantly adverse effect on respiratory emergency department visits. Conclusions Our findings provide novel evidence on SO2-by-temperature interactions, and NO2-by-temperature interactions for emergency department visits of cause-specific diseases.

Although epidemiological studies have evaluated the associations of ambient air pollution with depression, the results remained mixed. To clarify the nature of the association, we performed a comprehensive systematic review and meta-analysis with the Inverse Variance Heterogeneity (IVhet) model to estimate the effect of ambient air pollution on depression. Three English and four Chinese databases were searched for epidemiologic studies investigating associations of ambient particulate (diameter