Ozone, Heat Wave, and Cardiovascular Disease Mortality: A Population-Based Case-Crossover Study

Abstract

A case-crossover study among 511,767 cardiovascular disease (CVD) deaths in Jiangsu province, China, during 2015−2021 was conducted to assess the association of exposure to ambient ozone (O 3 ) and heat wave with CVD mortality and explore their possible interactions. Heat wave was defined as extreme high temperature for at least two consecutive days. Gridlevel heat waves were defined by multiple combinations of apparent temperature thresholds and durations. Residential O 3 and heat wave exposures were assessed using grid data sets (spatial resolution: 1 km × 1 km for O 3 ; 0.0625°× 0.0625°for heat wave). Conditional logistic regression models were applied for exposure−response analyses and evaluation of additive interactions. Under different heat wave definitions, the odds ratios (ORs) of CVD mortality associated with medium-level and high-level O 3 exposures ranged from 1.029 to 1.107 compared with low-level O 3 , while the ORs for heat wave exposure ranged from 1.14 to 1.65. Significant synergistic effects on CVD mortality were observed for the O 3 and heat wave exposures, which were generally greater with higher levels of the O 3 exposure, higher temperature thresholds, and longer durations of heat wave exposure. Up to 5.8% of the CVD deaths were attributable to O 3 and heat wave. Women and older adults were more vulnerable to the exposure to O 3 and heat wave exposure. Exposure to both O 3 and heat wave was significantly associated with an increased odds of CVD mortality, and O 3 and heat wave can interact synergistically to trigger CVD deaths.

Sex differences and dietary patterns in the association of air pollutants and hypertension

“…The possible sex difference in fitness conditions, vascular characteristics, percentage of body fat, and hormone levels may be responsible for the greater difficulty in dissipating heat for females. In addition, compared with males, females have slightly greater airway reactivity, it is possible that dose–response relations may be detected more easily in females than in males [ 49 ].…”

Effects of the interaction between cold spells and fine particulate matter on mortality risk in Xining: a case-crossover study at high altitude

“…To identify potential vulnerable groups, we classified them by altitude, sex, age, and level of education to assess the independent impacts of cold spells and PM 2.5 on non-accidental deaths and their interaction. We used a two-sample z-test to examine the differences in the effects estimated for each stratified variable (35)(36)(37).…”

Assessing the impact of short-term ozone exposure on excess deaths from cardiovascular disease: a multi-pollutant model in Nanjing, China’s Yangtze River Delta

“…Quantification of the CVD mortality burden indicates that the ozone-attributable CVD deaths in 2019 were 1,467.8 thousand, and by 2050, the estimated ozone-attributable CVD deaths in Chinese adults are expected to be 1,082.4 thousand and 359.2 thousand, respectively, according to SSP 585 and SSP 126 ( 9 ). A cohort study found that a 10 μg/m 3 increase in long-term annual average ozone exposure was associated with a 1.22 (95% confidence interval [CI]: 1.13–1.33) increase in adjusted hazard ratio for CVD deaths ( 10 ), while for short term ozone exposure, with lag 0–1 day, the odds ratio (OR) for CVD mortality ranged from 1.009 to 1.012 for each 10 μg/m 3 increase ( 11 ). During 2015–2021, the ozone concentration in Jiangsu Province showed an increasing trend ( 11 ), and Nanjing, a key development city and the capital city of Jiangsu Province, has maintained the same increasing trend of ozone pollution as Jiangsu Province, whose cardiovascular disease burden caused by ozone has aroused widespread public concern.…”

“…A cohort study found that a 10 μg/m 3 increase in long-term annual average ozone exposure was associated with a 1.22 (95% confidence interval [CI]: 1.13–1.33) increase in adjusted hazard ratio for CVD deaths ( 10 ), while for short term ozone exposure, with lag 0–1 day, the odds ratio (OR) for CVD mortality ranged from 1.009 to 1.012 for each 10 μg/m 3 increase ( 11 ). During 2015–2021, the ozone concentration in Jiangsu Province showed an increasing trend ( 11 ), and Nanjing, a key development city and the capital city of Jiangsu Province, has maintained the same increasing trend of ozone pollution as Jiangsu Province, whose cardiovascular disease burden caused by ozone has aroused widespread public concern. Additionally, in recent years, there is growing evidence that other air pollutants are also markedly associated with CVD deaths ( 12–14 ).…”