1. Acute effects of air pollution on all-cause mortality: a natural experiment from haze control measures in Chiang Mai Province, Thailand
- Author
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Nitaya Vajanapoom, Thuan-Quoc Thach, and Patcharee Kooncumchoo
- Subjects
Environmental Impacts ,Natural experiment ,Haze ,010504 meteorology & atmospheric sciences ,Epidemiology ,Haze smoke ,Haze control ,Air pollution ,lcsh:Medicine ,010501 environmental sciences ,medicine.disease_cause ,complex mixtures ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Interquartile range ,Environmental health ,medicine ,Spatial and Geographic Information Science ,Mortality ,0105 earth and related environmental sciences ,Pollutant ,General Neuroscience ,lcsh:R ,Absolute risk reduction ,General Medicine ,Particulates ,Seasonality ,medicine.disease ,Natural Resource Management ,Environmental science ,Public Health ,Particulate matter ,General Agricultural and Biological Sciences ,Health effects ,Biomass burning - Abstract
Background Serious haze episodes have been a seasonal event in Chiang Mai province for more than a decade. In 2008, local government agencies introduced comprehensive measures to control haze and limit its impacts on public health. This study assessed the acute effects of ambient air pollutants on all-cause mortality before and after the introduction of those haze control measures. Methods We obtained daily mortality counts and data on mass concentrations of particulate matter 10), gaseous pollutants (SO2, NO2, O3, and CO), and meteorology in Chiang Mai Province between January 2002 and December 2016. We analyzed the data using a case-crossover approach adjusting for temperature, relative humidity, seasonality, and day-of-week. We assessed change in the excess risks of all-cause mortality associated with an increase in interquartile range (IQR) of pollutant concentration before and after control measures came into force. Results We found decreased PM10 levels and markedly reduced excess risks of daily mortality associated with an IQR increase in PM10 concentrations in the years after haze-control measures were implemented (2009–2016). We found mixed results for gaseous pollutants: SO2 showed no significant change in excess risk of daily mortality throughout the study period, while NO2 and CO showed significant excess risks only in the period 2012–2016, and 8-h maximum O3 showed a decrease in excess risk despite an increase in its atmospheric levels after the introduction of haze control measures in 2008. Conclusions The findings indicate that the government haze control measures first introduced in Chiang Mai province in 2008 have successfully reduced episodic PM10 concentrations, which has led to a decrease in short-term all-cause mortality.
- Published
- 2020