Global burden of chronic obstructive pulmonary disease attributable to ambient ozone in 204 countries and territories during 1990-2019

Ambient ozone becomes one of significant environmental threats to chronic obstructive pulmonary disease (COPD) in recent decades. To date, however, few systematic analyses have been performed to quantify ozone-attributable disease burden, globally and regionally. In this study, we aimed to comprehensively depict the global trend of ozone-related COPD premature deaths and disability-adjusted life years (DALYs). We derived estimates of COPD burden attributable to ambient ozone for 204 countries and territories during 1990-2019 from the Global Burden of Disease Study 2019. We examined the number of deaths and DALYs, as well as age-standardized mortality rate (ASMR) and DALYs rate (ASDR) by sex, socio-demographic index (SDI), countries, and regions. Population attributable fractions (PAFs) were adopted to identify age groups vulnerable to ozone-related COPD. Estimated annual percentage changes (EAPCs) were calculated to assess the temporal trend of ozone-attributable COPD burden (e.g., ASMR and ASDR) between 1990 and 2019, using generalized linear models. Spearman rank correlation was applied to measure the relationships of estimated ASMR, ASDR, and EAPC with SDI. In 2019, COPD attributable to ambient ozone gave rise to 365.22 (95% uncertainty interval: 174.93 to 564.27) thousand deaths and 6.21 (2.99 to 9.63) million DALYs globally, representing a corresponding increase of 76.11% and 56.37% versus 1990. During 1990-2019, however, a yearly decline of 1.07% (0.81 to 1.33) was observed for ASMR and 1.30% (1.07 to 1.52) for ASDR. Considerable gender inequality continues in ozone-attributable COPD burden, with much greater impacts among men, and the gap is enlarged with the increase of age. In all age groups, the fractional contribution of ozone to COPD burden exhibited an overall increasing trend globally for both deaths (8.22% in 1990 versus 11.13% in 2019) and DALYs (6.70% in 1990 versus 8.34% in 2019). The burden of COPD caused by ambient ozone varied substantially by geographical and socioeconomic regions. In 2019, the greatest ASMR and ASDR were seen in South Asia, followed by East Asia and Central Sub-Saharan Africa. Despite the clear drop of age-standardized rates (EAPC<0) in high, high-middle, and middle SDI regions, ASMR and ASDR in low and low-middle SDI regions continuously raised between 1990 and 2019. Higher SDI was found to be associated with lower EAPCs in ASMR (r(s)=-0.4405, p<0.001) and ASDR (r(s)=-0.4510, p<0.001). Although the global ASMR and ASDR of COPD attributable to ambient ozone have decreased from 1990 to 2019, there has been an unnegligible increase in some low and low-middle SDI regions such as Southeast Asia, South Asia, and Andean Latin America. Findings may have some implications for formulating targeted plans and policies for future COPD prevention and ambient ozone management in different regions.