Effects of Ozone
Long-term exposure to ground-level ozone is associated with the development of chronic obstructive pulmonary disease (COPD), a progressive and debilitating disease that makes it harder to breathe. We analyze the burden of disease attributable to ozone based on its contribution to death and disability from COPD.
Ozone has serious health consequences.
Long-term exposure to ground-level ozone contributed to an estimated 365,000 deaths (95% UI : 175,000 to 564, 000) in 2019. That equates to about 11% (95% UI: 5.3 to 17) of all COPD deaths globally.
Over 70% of these deaths occurred in India – 168,000 (95% UI: 82,000 to 262,000) – and China – 93,300 (95% UI: 42,700 to 151,000) reflecting their higher ozone exposures, large populations and higher age-standardized COPD death rates attributed to ozone. India’s death rate was 18/100,000 population compared with China’s 5.9/100,000 and a global rate of 4.7/100,000. By comparison, the number of ozone-attributable deaths in GBD High Income Super Region countries accounted for less than 9% of the global total or about 32,300 95% UI: 14,100 to 53,100. The ozone attributable death rate for the region was 1.3/100,000.
Deaths from ozone-attributable COPD are rising despite declines in mortality rates.
Global mortality rates from COPD attributable to ozone have declined by nearly 13% (95% UI: -20.3 to -4.9) over the past decade. However, the overall number of associated deaths increased by 16% (95% UI: 5.8 to 26.7). This difference is largely explained by changing sociodemographic factors, in particular the aging of populations.
Regional trends in total mortality burden attributable to ozone vary widely, reflecting regional differences in ozone exposures and COPD mortality rates, as well as underlying health and population characteristics.
Fifteen of the 20 most populous countries experienced increases in ozone-attributable deaths over the past decade. The largest proportional increases were seen in Brazil (which saw a 191% increase in ozone-attributable deaths), Ethiopia (171%), the Democratic Republic of the Congo (97%), and Indonesia (89%). Given that these countries experienced only small increases in ozone exposure during the same time period, and COPD mortality rates have been largely stagnant over this time period, the increases largely reflect the growing numbers of older adults in the population.
Older adults — and countries with aging populations — suffer the highest burden.
COPD typically takes many years to develop as a result of long-term exposure to ozone and other irritants. As a result, it takes its toll primarily in older adults. The health burden of ozone-attributable COPD is rising in countries with aging populations.
The growth and aging of populations accounts for much of the increase in COPD-related deaths in countries across Asia. Because of these countries’ large populations, these trends in turn strongly influence the overall global increase in the number of ozone-attributable deaths from COPD.