Study On Effects Of Ambient Particulate Matter And Its Constituents On Deaths From A Spectrum Of Diseases In Guangzhou

Air pollution is still an important threat to public health,among which the impact of fine particles is the most serious.Though,air quality has significantly improved after the implementation of the“Air Pollution Prevention and Control Action Plan”and“Blue Sky Protection Campaign”in 2013,the annual average concentration of PM_2.5 is still well beyond the WHO guideline level of PM_2.5（10μg/m³）.Furthermore,most previous studies on particulate matters and their constituents were mainly focused on the common health outcomes,such as cardiovascular disease and respiratory disease.In this study,we aimed to apply the generalized additive model to assess impacts of particulate matters(ie,PM₁,PM_2.5 and PM₁₀)from 2014 to 2016 and residuals of PM_2.5constituents(EC,OC,SO₄^2-,NO₃^-,NH₄⁺)from 2011-2015 on mortality from 36 diseases（10 broad categories and 26 subcategories）.The confounding variables,including long-term trend,temperature,relative humidity and holiday effects,were also included in the model.Then,stratification analyses were further performed according to demographic characteristics（such as ages and genders）,seasons,and the level of weather condition.The health benefits of PMs were finally assessed if their concentrations were restricted to the targeted levels.Results showed that PM₁,PM_2.5,PM₁₀,EC,OC and NO₃^-presented significant effects on mortality from all-cause,non-accidental and circulatory diseases at lag 03 day.Significant effects of PM₁,PM_2.5,PM₁₀ and EC were also observed on respiratory disease mortality.However,no significant harmful effects of all these particles and PM_2.5 components on deaths from digestive diseases,nervous diseases,genitourinary diseases and external causes.In addition,effects of PM₁and PM₁₀ on neoplasm,as well as PM₁₀ and NO₃^-on mortality from endocrine diseases were found to be statistically significant.In the subgroup analysis,similar estimates were observed for men and women,but higher estimates were generally found for the elderly than the youth.The effects of particles on circulatory diseases were more obvious in spring and summer,while the effects on respiratory diseases and tumors were greater in autumn and winter,respectively.And stronger impacts of EC and OC were generally observed in summer than in winter but NO₃^-in autumn.In addition,higher risks of pollutants were found under the situation that high temperature with high humidity and low temperature with low humidity.When PM₁,PM_2.5,and PM₁₀ do not exceed 20,25 and 50μg/m³,respectively,at least 3367,3974,and 3076 deaths can be reduced during the study period.Apart from PM_2.5 and the combustion source pollutants（EC and OC）,more attention from the government and relevant departments is suggested on PM₁ and NO₃^-.In particular,more warning and protections are needed for the elderly.Our findings highlighted that stricter emission control measures are still warranted to reduce air pollution concentration and protect public health.