Ozone pollution in Chinese cities: Assessment of seasonal variation, health effects and economic burden.

The ground-level ozone (O) concentration in the urban regions of China has become an increasingly noticeable environmental problem in recent years. Many epidemiological studies have reported the association between O pollution and mortality, only a few studies have focused on the O-related mortality and corresponding economic effects at the Chinese city and province level. This study reports the seasonal variation of ground-level O in 338 cities of China during the year 2016 and evaluates its effect on premature mortality and economic loss. It further illustrates the differences in cause-specific mortality outcomes of the log-linear and linear model, two of the prominently used methods for estimating health effects. In 2016, the annual average daily maximum 8-h O concentration in China ranged between 74 and 201 μg/m (138 ± 24.7 μg/m). 30% of the total population was exposed to >160 μg/m O concentration (Chinese national ambient air quality standard) and about 67.2% urban population lived in exposure above the WHO recommended O concentrations (100 μg/m). The estimated national O-attributable mortality was 74.2 × 10 (95% CI: 16.7×10-127×10) in the log-linear model, whereas, the total O-related mortality using the linear model was 69.6 × 10 (95% CI: 16.2 × 10-115 × 10). The exposure to O caused a nationwide economic loss of about 7.6 billion US$ (range: 1.7-12.9) in 2016. This study uniquely provides most comprehensive coverage of the Chinese cities for O associated mortality utilizing ground level measurement data for 2016 and presents a measurable assessment to the policymakers of China for streamlining their efforts on air quality improvement and O containment.