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Objective To quantitatively evaluate the association of short-term exposure to ambient submicron particulate matter (PM1) with hospital admissions for angina in older adults. Methods A case-crossover study was conducted among 46 687 older adults hospitalized for angina from 2016 to 2019 in Guangzhou medical institutions. Grid data on ambient PM1 concentrations in Guangzhou were obtained from the ChinaHighAirPollutants (CHAP) dataset. Exposure to PM1 was assessed according to each subject's residential addresses. Conditional logistic regression model was used to analyze the the exposure-response association between PM1 and hospital admissions for angina. Results From 2016 to 2019, the average exposure level of PM1 on the same day of hospital admissions (lag 0) for angina was 21.0 ± 11.5 μg/m3. The results of main model analysis showed that lag 0 day exposure to ambient PM1 was significantly associated with a higher odds of hospital admissions for angina in older adults. Each 10 μg/m3 increase of PM1 exposure level was significantly associated with a 1.31% (95% CI: 0.05%, 2.59%) increased odds of angina admissions. Results from a two-pollutant model adjusting for O3 showed that the association between short-term exposure to PM1 and odds of hospitalization for angina remained stable. According to the results of the above model, it was estimated that the excess hospitalization attributable to ambient PM1 exposure accounted for 2.46% (95% CI: 0.09%, 4.76%) of the total admissions in Guangzhou during 2016-2019, corresponding to 1539 (95% CI: 54, 2976) admissions. No significant effect modification on the associations was observed by sex, age, or season. Conclusion Short-term exposure to ambient PM1 was significantly associated with an increased odds of hospital admissions for angina in older adults.
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Objective To investigate the association between short-term exposure to ambient air pollution and hospital admission for ischemic stroke among older adults. Methods Using clinical monitoring data from China National Health Commission, we identified 124 297 individuals from Guangzhou, Guangdong province, China who were 60 years or older and were admitted to hospital for ischemic stroke in 2016-2019. We used a time-stratified case-crossover design and employed the conditional logistic regression model to investigate the exposure-response association between short-term exposure to air pollution and hospital admission for ischemic stroke. Based on each subject's residential address and pollutant data from its neighboring air quality monitoring stations, we used an inverse distance weighting method to assess individual-level exposure to PM2.5, PM10, SO2, NO2, CO and O3 on each of the case and control days. Results In single-pollutant models, each 10 µg/m3 increase of PM2.5, PM10, SO2, NO2, CO and O3 was associated with a 0.46% (95% confidence interval [CI]: 0.13-1.36%, lag 2 d), 0.66% (1.38-2.93%, lag 02 d), 3.39% (0.07-0.21%, lag 2 d), 1.47% (0.07-0.21%, lag 02 d), 0.06% (0.07-0.21%, lag 02 d) and 0.18% (0.07-0.21%, lag 3 d) increase in odds of hospital admission, respectively. The results of 2-pollutant models showed that the association of exposure to SO2, NO2 and O3 with hospital admission for ischemic stroke remained stable with adjustment for each of the other air pollutants. Conclusions Short-term exposure to ambient air pollution, especially SO2, NO2 and O3, was associated with increased risk of hospital admission for ischemic stroke in older adults.
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Ambient fine particulate matter (PM2.5) is a mixture consisting of a wide range of chemical constituents including carbonaceous aerosols, water soluble ions and inorganic elements, and has become the major air pollutant in most cities in China. Evidence suggests that exposure to ambient PM2.5 induces damage on the cardiovascular system and can increase risk of the development and mortality of ischemic heart diseases (IHD). However, the effects of exposure to specific PM2.5 constituents on IHD remain unclear, and its underlying mechanisms are yet to be investigated. Here we reviewed studies investigating the association of short- and long-term exposure to specific PM2.5 constituents with IHD, which may provide useful clues for future relevant studies.
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With the continuous development of society and economic activities, ambient air pollution has become an important global environmental and public health issue, and its significant adverse effects on human health have attracted increasing attention. Previous studies have shown a significant association between air pollution exposure and cardiovascular events including cardiac arrest. Although the association between air pollution exposure and risk of cardiac arrest has been identified by several studies, the results remain inconsistent and the pathogenic mechanism is not yet clear. To date, most studies focused on the impact of air pollution exposure on the onset of cardiac arrest, while few studies explored the risk of death from cardiac arrest. Here we reviewed studies investigating the association between short-term exposure to air pollution and risk of cardiac arrest.
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Objective@#To investigate the effects of crystalline silica with different exposure patterns on lung fibrosis in rats.@*Methods@#A total of 20 adult male Wistar rats were randomly divided into 4 groups consisting of five animals each and received intratracheal instillation of sterile saline or silica suspension in different patterns: saline once at day 0, saline once/week, crystalline silica 50 mg at day 0, crystalline silica 6.25 mg/week. The rats were sacrificed at 8 weeks. The lung tissues were collected for pathological analyses, and determining mRNA and protein levels of related fibrogenic molecules.@*Results@#The collagen deposition induced by crystalline silica in lung tissues were increased. The mRNA levels of IL-1β and Col I in group c were significantly elevated than those in group saline once at day 0 (all P<0.05). Compared with group saline once/week, the mRNA levels of IL-1β, TGF-β, Col I, Col III and CTGF were significantly increased in group crystalline silica 6.25 mg/week (P<0.05) . The mRNA levels of Col I and CTGF were significantly increased in group crystalline silica 6.25 mg/week in comparison with those in group crystalline silica 50 mg at day 0 (P<0.05) .@*Conclusion@#Given the same cumulative dose of crystalline silica, multiple exposures were likely to induce more severe lung fibrosis.
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<p><b>OBJECTIVE</b>The objective of this study was to investigate the aspiratory resistance, filtration penetration and their influence factors of N95 filtering-facepiece respirators used widely in China.</p><p><b>METHODS</b>The total of 6 brands and 21 models of N95 filtering-facepiece respirators which are certified and big sales on the market. The aspiratory resistance and filtration efficiency filter penetration were measured while air pump ran from 10 L/min to 100 L/min using differential pressure gauge and the PortaCount, respectively.</p><p><b>RESULTS</b>The filtration penetrations for 2 of the 21 models were lower than 95%, and the qualified rate for all models was 90.47%. The filtration penetrations gradually decreased when ventilation flow of air pump increased. The negative correlation was observed between filtration penetration and ventilation flow (r(2) = 0.711, P < 0.05). The resistances of all 21 models of N95 respirators met the requirements of the national standard. The aspiratory resistance started to elevate with the increasing of ventilation flow, and a positive correlation between both (r(2) = 0.878, P < 0.05). Significant differences of filtration penetration and aspiratory resistance were observed among between different brands (P < 0.05) although no differences of filtration penetration existed among different models of one brand (P > 0.05). But the differences of the aspiratory resistance among different models of one brand were statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>The aspiratory resistances of all N95 filtering-facepiece respirators used in this study met the requirements of the national standard. And the qualified ratio of filtration penetration of all models was higher than 90%. The influencing factors of aspiratory resistance included materials, size and ventilation flow. And influencing factors for filtration penetration were materials and ventilation flow.</p>
Subject(s)
Air Pollutants, Occupational , China , Equipment Design , Filtration , Masks , Reference Standards , Materials Testing , Respiratory Protective Devices , Reference StandardsABSTRACT
As a nonparametric method, the Kruskal-Wallis test is widely used to compare three or more independent groups when an ordinal or interval level of data is available, especially when the assumptions of analysis of variance (ANOVA) are not met. If the Kruskal-Wallis statistic is statistically significant, Nemenyi test is an alternative method for further pairwise multiple comparisons to locate the source of significance. Unfortunately, most popular statistical packages do not integrate the Nemenyi test, which is not easy to be calculated by hand. We described the theory and applications of the Kruskal-Wallis and Nemenyi tests, and presented a flexible SAS macro to implement the two tests. The SAS macro was demonstrated by two examples from our cohort study in occupational epidemiology. It provides a useful tool for SAS users to test the differences among three or more independent groups using a nonparametric method.
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The influence of exercise at high temperature on adult males' routine blood indexes and biochemical indexes and the expression of HSP72 in peripheral blood lymphocytes (PBLs) was studied in order to provide theoretical ground for health supervision of adults receiving exercise at high temperature. 180 adult males were selected and divided into exercise group and control group, in which the exercise group was subdivided into subgroup 1 and subgroup 2 receiving exercise at high temperature in the afternoon and in the morning, respectively. Peripheral venous blood was phlebotomized before and after the exercise to examine routine blood indexes and blood biochemical indexes. The expression levels of HSP72 in PBLs were detected by flow cytometry. The results showed that the routine blood indexes and biochemical indexes in each group were within the range of normal values of male adults. There was no significant difference between each exercise group and control group in indexes before exercise. After exercise, the expression levels of HSP72 in PBLs in exercise groups were higher than those before exercise, and HSP72 expression levels in subgroup 1 were obviously higher than those in subgroup 2 and control group. The contents of ALT, urea, Na+, Cl-, Ca2+ and K+ in subgroups 1 and 2 were lower than those in control group, but CK level was higher than in control group (P<0.05). The contents of Na+ and Cl- in subgroup 1 were relatively lower than those in subgroup 2 (P<0.05). It was concluded that while receiving exercise at high temperature, adult males' HSP72 levels in PBLs could be increased and the biochemical indexes changed. Attention should be paid to health supervision to avoid obvious body injuries at high temperature.
Subject(s)
Young Adult , Blood Chemical Analysis/methods , Exercise/physiology , HSP72 Heat-Shock Proteins/blood , HSP72 Heat-Shock Proteins/metabolism , Hot Temperature , Lymphocytes/metabolismABSTRACT
To investigate the health impacts of crystalline silica mixed dust and other potential occupational hazards on workers in ceramic factories, a cohort study of 4851 workers registered in the employment records in 3 ceramic factories in Jingdezhen city of China between 1972 and 1974 was identified. The cohort mortality was traced throughout 2003 with an accumulation of 128970.2 person-years, revealed 1542 deaths. Standardized mortality ratios (SMRs) were calculated for the main causes of death by using Chinese national mortality rates as reference. The mortality from all causes in three ceramic factories was 12.0 per thousand and the cumulative mortality was 31.8%. Malignant neoplasm, cardiovascular diseases, respiratory diseases, infectious diseases were the first four illnesses that threaten workers' life, and they accounted for 73.2% of all deaths. The results of this study showed that the standardized mortality ratio for all subjects was 1.02, which is very close to that expected on the basis of the China national mortality rates. Statistically significant mortality excesses for respiratory disease (SMR=1.36), pneumoconiosis (SMR=37.34), infectious disease (SMR=5.70) and pulmonary tuberculosis (SMR=3.88) were observed. The mortality of 2938 dust-exposed workers was higher than that of 1913 non dust-exposed workers. Except for pneumoconiosis, the mortality from lung cancer, non-malignant respiratory diseases and pulmonary tuberculosis in dust-exposed workers were significantly increased as compared with that in non-exposed workers, and the relative risks (RRs) were 1.86 (1.16-2.99), 2.50 (1.84-3.40), 1.81 (1.34-2.45). The exposure-response relationships between cumulative dust exposure level and mortality from all causes, colorectal cancer, lung cancer, respiratory diseases, and pulmonary tuberculosis were also identified. The findings indicated that silica mixed dust in ceramic factories has harmful impact on the workers' health and life span in ceramic factory.