Effect of exposure to ambient PM2.5 pollution on the risk of respiratory tract diseases： a meta-analysis of cohort studies

The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates, including particulates of median aerodynamic diameter 〈 2.5 gm （PM2.5）, as Group 1 carcinogens. It has not been determined, however, whether exposure to ambient PM2.5 is associated with an increase in respiratory related diseases. This meta-analysis assessed the association between exposure to ambient fine particulate matter （PM2.5） and the risk of respiratory tract diseases, using relevant articles extracted from PubMed, Web of Science, and Embase. In results, of the 1,126 articles originally identified, 35 （3.1%） were included in this meta-analysis. PM2.5 was found to be associated with respiratory tract diseases. After subdivision by age group, respiratory tract disease, and continent, PM2.5 was strongly associated with respiratory tract diseases in children, in persons with cough, lower respiratory illness, and wheezing, and in individuals from North America, Europe, and Asia. The risk of respiratory tract diseases was greater for exposure to traffic-related than non-traffic-related air pollution. In children, the pooled relative risk （RR） represented significant increases in wheezing （8.2%）, cough （7.5%）, and lower respiratory illness （15.3%）. The pooled RRs in children were 1.091 （95%CI： 1.049, 1.135） for exposure to 〈 25 gg/m3 PM2.5, and 1.126 （95%CI： 1.067, l. 190） for exposure to 〉 25 gg/m3 PM2.5. In conclusion, exposure to ambient PM2.5 was significantly associated with the development of respiratory tract diseases, especially in children exposed to high concentrations of PM2.5.

Epidemiological characteristics of centenarian deaths in China during 2013-2020:A trend and subnational analysis

Background:Studies that comprehensively address the characteristics of centenarian deaths are rare.The present study aimed to depict the characteristics of centenarian deaths in China and their changing trends.Methods:Data on centenarian deaths between 2013 and 2020 were obtained from the national mortality surveillance system of China,including date,place of death(PoD),and underlying cause of death(CoD).Descriptive analyses were performed to understand the epidemiological characteristics,and a joinpoint regression model was adopted to examine the changing trends in the proportions of different PoDs,CoDs among centenarians,and centenarian deaths accounting for all deaths and deaths among people aged 65 years and older.Results:There were 46,938 registered centenarian deaths between 2013 and 2020 that included 34,311 females(73.10%)and 12,627 males(26.90%).January(12.05%),February(9.99%),and December(9.74%)were the top three months with the highest number of deaths.The proportions of deaths that occurred in homes,hospitals,and nursing homes were 81.71%,13.63%,and 2.68%,respectively.The proportion of deaths in nursing homes increased by 9.60%(95%confidence intervals[CIs],6.4-12.9%)from 2014 to 2020.Heart disease(35.72%)was the leading cause of death,followed by respiratory diseases(17.63%),cerebrovascular disease(15.60%),and old age(11.22%).The proportion of respiratory diseases decreased by 4.8%(95%CI,-8.8 to-0.7%),and the proportion of deaths from old age decreased by 2.3%(95%CI,-4.4 to-0.1%)per year.Shanghai had the highest proportions of deaths in hospitals(39.38%)and nursing homes(14.68%).Sichuan had the highest proportion of deaths attributed to respiratory diseases(32.30%),while Jiangsu(26.58%)and Zhejiang(23.61%)had the highest proportions of deaths from old age.Conclusion:Unlike other countries,centenarian deaths in China are characterized by a higher proportion of home and heart disease deaths,and this death pattern differs across provinces.