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Air pollution is a major cause of specific deaths worldwide. This review article aimed to investigate the results of cohort studies for air pollution connected with the all-cause, cardio-respiratory, and lung cancer mortality risk by performing a meta-analysis. Relevant cohort studies were searched in electronic databases (PubMed/Medline, Web of Science, and Scopus). We used a random effect model to estimate the pooled relative risks (RRs) and their 95% CIs (confidence intervals) of mortality. The risk of bias for each included study was also assessed by Office of Health Assessment and Translation (OHAT) checklists. We applied statistical tests for heterogeneity and sensitivity analyses. The registration code of this study in PROSPERO was CRD42023422945. A total of 88 cohort studies were eligible and included in the final analysis. The pooled relative risk (RR) per 10 μg/m3 increase of fine particulate matter (PM2.5) was 1.080 (95% CI 1.068–1.092) for all-cause mortality, 1.058 (95% CI 1.055–1.062) for cardiovascular mortality, 1.066 (95%CI 1.034–1.097) for respiratory mortality and 1.118 (95% CI 1.076–1.159) for lung cancer mortality. We observed positive increased associations between exposure to PM2.5, PM10, black carbon (BC), and nitrogen dioxide (NO2) with all-cause, cardiovascular and respiratory diseases, and lung cancer mortality, but the associations were not significant for nitrogen oxides (NOx), sulfur dioxide (SO2) and ozone (O3). The risk of mortality for males and the elderly was higher compared to females and younger age. The pooled effect estimates derived from cohort studies provide substantial evidence of adverse air pollution associations with all-cause, cardiovascular, respiratory, and lung cancer mortality. [ABSTRACT FROM AUTHOR]

Although a growing number of original epidemiological studies imply a link between ambient pollution exposure and mortality risk, the findings associated with carbon monoxide (CO) exposure are inconsistent. Thus, we conducted a systematic review and meta-analysis of epidemiological studies to evaluate the correlations between ambient CO and non-accidental, cardiovascular, and respiratory mortality in China. Eight databases were searched from inception to 15 May 2021. A random-effect model was used to calculate the pooled relative risks (RRs) and 95% confidence intervals (CIs). Subgroup analyses as well as sensitivity analyses were performed. The I square value (I2) was used to assess heterogeneity among different studies. The assessment of publication bias on included studies was examined by funnel plot and Egger's test. The influence of a potential publication bias on findings was explored by using the trim-and-fill procedure. Ultimately, a total of 19 studies were included in our analysis. The pooled relative risk for each 1 mg/m3 increase of ambient carbon monoxide was 1.0220 (95%CI: 1.0102–1.0339) for non-accidental mortality, 1.0304 (95%CI:1.0154–1.0457) for cardiovascular mortality, and 1.0318 (95%CI:1.0132–1.0506) for respiratory mortality. None of subgroup analyses could explain the source of heterogeneity. Exclusion of any single study did not materially alter the pooled effect estimates. Although it was suggestive of publication bias, findings were generally similar with principal findings when we explored the influence of a potential publication bias using the trim-and-fill method. Our meta-analysis demonstrated that exposure to ambient CO was positive with risk of deaths from all non-accidental causes, total cardiovascular, and respiratory diseases. Based on these findings, tougher intervention policies and initiatives to reduce the health effects of CO exposure should be established. [ABSTRACT FROM AUTHOR]

The spatial synoptic classification (SSC) is a holistic categorical assessment of the daily weather conditions at specific locations; it is a useful tool for assessing weather effects on health. In this study, we assessed (a) the effect of hot weather types and the duration of heat events on cardiovascular and respiratory mortality in summer and (b) the effect of cold weather types and the duration of cold events on cardiovascular and respiratory mortality in winter. A time-stratified case-crossover design combined with a distributed lag nonlinear model was carried out to investigate the association of weather types with cause-specific mortality in two southern (Skåne and Stockholm) and two northern (Jämtland and Västerbotten) locations in Sweden. During summer, in the southern locations, the Moist Tropical (MT) and Dry Tropical (DT) weather types increased cardiovascular and respiratory mortality at shorter lags; both hot weather types substantially increased respiratory mortality mainly in Skåne. The impact of heat events on mortality by cardiovascular and respiratory diseases was more important in the southern than in the northern locations at lag 0. The cumulative effect of MT, DT and heat events lagged over 14 days was particularly high for respiratory mortality in all locations except in Jämtland, though these did not show a clear effect on cardiovascular mortality. During winter, the dry polar and moist polar weather types and cold events showed a negligible effect on cardiovascular and respiratory mortality. This study provides valuable information about the relationship between hot oppressive weather types with cause-specific mortality; however, the cold weather types may not capture sufficiently effects on cause-specific mortality in this sub-Arctic region. [ABSTRACT FROM AUTHOR]

Chronic respiratory diseases cause huge death burden worldwide, especially in developing countries. The influence of ambient temperature on respiratory mortality has attracted growing concerns in the background of climate change. Daily cause-specific respiratory deaths and meteorological variables were collected from 16 Chinese cities during 2007–2013. We first applied the distributed lag non-linear model for each city to calculate the percentage change in respiratory mortality risk with a 1 °C change in moderate and extreme temperature range. Then, random-effect meta-analytical approach was used to produce the pooled effects. Individual-level and city-level effect modifications were separately assessed by the stratified analysis and mixed effects meta-regression model. Both cold and heat effects were associated with respiratory mortality. The pooled excess risk was 4.40% (95%CI: 2.75–6.08%), 2.23% (1.19–3.28%), 2.64% (1.81–3.47%), and 4.21% (3.10–5.33%) for 1 °C change among extreme cold, moderate cold, moderate heat, and extreme heat, respectively. Positive heat and cold effects were found for COPD, asthma, and pneumonia, among which asthma was most vulnerable to extreme cold temperatures, with the effect estimate of 6.52% (2.73–10.46%). The heat effects were much higher in females than males. Slightly higher risks were also observed in the elderly during the heat, and those with lower education level during the heat and extreme cold. City-level modifiers included green coverage rates and diurnal temperature range. Ambient heat and cold temperatures are positively associated with respiratory mortality in China. Individual and city-specific effect modifiers should be taken into consideration in policy-making. [ABSTRACT FROM AUTHOR]

Although the growths of ambient pollutants have been attracting public concern, the characteristic of the associations between air pollutants and mortality remains elusive. Time series analysis with a generalized additive model was performed to estimate the associations between ambient air pollutants and mortality outcomes in Shenzhen City for the period of 2012-2014. The results showed that nitrogen dioxide (NO)-induced excess risks (ER) of total non-accidental mortality and cardiovascular mortality were significantly increased (6.05% (95% CI 3.38%, 8.78%); 6.88% (95% CI 2.98%, 10.93%), respectively) in interquartile range (IQR) increase analysis. Also, these associations were strengthened after adjusting for other pollutants. Moreover, similar associations were estimated for sulfur dioxide (SO), particulate matter with an aerodynamic diameter of <10 μm (PM), and total non-accidental mortality. There were significant higher ERs of associations between PM and mortality for men than women; while there were significant higher ERs of associations between PM/NO and mortality for elders (65 or elder) than youngers (64 or younger). Season analyses showed that associations between NO and total non-accidental mortality were more pronounced in hot seasons than in warm seasons. Taken together, NO was positively associated with total non-accidental mortality and cardiovascular mortality in Shenzhen even when the concentrations were below the ambient air quality standard. Policy measures should aim at reducing residents' exposure to anthropogenic NO emissions. [ABSTRACT FROM AUTHOR]

Although interest in assessing the impacts of hot temperature and mortality in Hong Kong has increased, less evidence on the effect of cold temperature on mortality is available. We examined both the effects of heat and cold temperatures on daily mortality in Hong Kong for the last decade (2002-2011). A quasi-Poisson model combined with a distributed lag non-linear model was used to assess the non-linear and delayed effects of temperatures on cause-specific and age-specific mortality. Non-linear effects of temperature on mortality were identified. The relative risk of non-accidental mortality associated with cold temperature (11.1 °C, 1st percentile of temperature) relative to 19.4 °C (25th percentile of temperature) was 1.17 (95 % confidence interval (CI): 1.04, 1.29) for lags 0-13. The relative risk of non-accidental mortality associated with high temperature (31.5 °C, 99th percentile of temperature) relative to 27.8 °C (75th percentile of temperature) was 1.09 (95 % CI: 1.03, 1.17) for lags 0-3. In Hong Kong, extreme cold and hot temperatures increased the risk of mortality. The effect of cold lasted longer and greater than that of heat. People older than 75 years were the most vulnerable group to cold temperature, while people aged 65-74 were the most vulnerable group to hot temperature. Our findings may have implications for developing intervention strategies for extreme cold and hot temperatures. [ABSTRACT FROM AUTHOR]

Recent epidemiological and toxicological studies have shown associations between particulate matter and human health. However, the estimates of adverse health effects are inconsistent across many countries and areas. The stratification and interaction models were employed within the context of the generalized additive Poisson regression equation to examine the acute effects of fine particles on respiratory health and to explore the possible joint modification of temperature, humidity, and season in Beijing, China, for the period 2004-2009. The results revealed that the respiratory health damage threshold of the PM concentration was mainly within the range of 20-60 μg/m, and the adverse effect of excessively high PM concentration maintained a stable level. In the most serious case, an increase of 10 μg/m PM results in an elevation of 4.60 % (95 % CI 3.84-4.60 %) and 4.48 % (95 % CI 3.53-5.41 %) with a lag of 3 days, values far higher than the average level of 0.69 % (95 % CI 0.54-0.85 %) and 1.32 % (95 % CI 1.02-1.61 %) for respiratory mortality and morbidity, respectively. There were strong seasonal patterns of adverse effects with the seasonal variation of temperature and humidity. The growth rates of respiratory mortality and morbidity were highest in winter. And, they increased 1.4 and 1.8 times in winter, greater than in the full year as PM increased 10 μg/m. [ABSTRACT FROM AUTHOR]

The associations between temperature and daily mortality was studied among the citizens of Oslo, Norway, 1990–1995. Data on daily mortality were linked with daily temperatures, relative humidity, wind velocity and air pollution. At temperatures below 10 °C, a 1 °C fall in the last 7 days average temperature increased the daily mortality from all diseases by 1.4%, respiratory diseases 2.1%, and cardiovascular diseases 1.7%. Above 10 °C, there was no statistically significant increase in daily mortality, except for respiratory mortality, which increased by 4.7% per 1 °C increase in the last 7 days average temperature. Daily mortality in Oslo increases with temperatures falling below 10 °C. The increase starts at lower temperatures than shown in warmer regions of the world, but at higher temperatures than in regions with even colder climates. As well insulated and heated dwellings are standard in Norway today, more adequate clothing during outdoor visits is probably the most important preventive measure for temperature related mortality. [ABSTRACT FROM AUTHOR]

Poor air quality is one of the most important environmental problems in many large cities of the world, which can cause a wide range of acute and chronic health effects, including partial physiological disorders and cardiac death due to respiratory and cardiovascular diseases. According to the latest edition of the national standard for air quality, maximum contamination level is 15 μg/m3 per year and 35 μg/m3 per day. The aim of this study was to evaluate cardiovascular, respiratory, and total mortality attributed to PM2.5 in the city of Mashhad during 2013. To this end, the Air Q model was used to assess health impacts of PM2.5 and human exposure to it. In this model, the attributable proportion of health outcome, annual number of excess cases of mortality for all causes, and cardiovascular and respiratory diseases were estimated. The results showed that the number of excess cases of mortality for all causes and cardiovascular and respiratory diseases attributable to PM2.5 was 32, 263, and 332 μg/m3, respectively. Moreover, the annual average of PM2.5 in Mashhad was obtained to be 37.85 μg/m3. This study demonstrated that a high percentage of mortality resulting from this pollutant could be due to the high average concentration of PM2.5 in the city during 2013. In this case, using the particle control methods, such as optimal use of fuel, management of air quality in urban areas, technical inspection of vehicles, faster development of public transport, and use of industrial technology can be effective in reducing air pollution in cities and turning existing situations into preferred ones. [ABSTRACT FROM AUTHOR]