Residential Nitrogen Dioxide Exposure and Cause-Specific Cerebrovascular Mortality: An Individual-Level, Case-Crossover Study

Yifeng Qian; Renzhi Cai; Xiaozhen Su; Qi Li; Shan Jin; Wentao Shi; Renjie Chen; Chunfang Wang; Jia He

doi:10.3390/toxics12010010

Residential Nitrogen Dioxide Exposure and Cause-Specific Cerebrovascular Mortality: An Individual-Level, Case-Crossover Study

Toxics. 2023 Dec 22;12(1):10. doi: 10.3390/toxics12010010.

Authors

Yifeng Qian^{1

2}, Renzhi Cai³, Xiaozhen Su⁴, Qi Li³, Shan Jin³, Wentao Shi⁵, Renjie Chen⁴, Chunfang Wang³, Jia He¹

Affiliations

¹ Department of Health Statistics, Naval Medical University, Shanghai 200433, China.
² Department of Oral and Craniomaxillofacial Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, Shanghai 200011, China.
³ Division of Vital Statistics, Institute of Health Information, Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China.
⁴ School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and NHC Key Lab of Health Technology Assessment, Fudan University, Shanghai 200032, China.
⁵ Clinical Research Unit, School of Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai 200011, China.

Abstract

Background: Existing studies have already shown a connection between nitrogen dioxide (NO₂) exposure and cerebrovascular mortality. However, the differential effects of NO₂ on cerebrovascular disease and its subtypes remain unclear and require further exploration.

Methods: Daily stroke mortality data between 2013 and 2021 in Shanghai, China were collected. Residential daily air pollution data for each decedent were predicted from a satellite model. An individual-level, time-stratified, case-crossover design was applied to examine the relationship between NO₂ exposure and cerebrovascular mortality. A combination of conditional logistic regression and distributed lag models with a maximum lag of 7 days was used for data analysis.

Results: A total of 219,147 cases of cerebrovascular mortality were recorded. Among them, the proportion of sequelae of cerebrovascular disease, hemorrhagic stroke and ischemic stroke was 50.7%, 17.1% and 27.5%, respectively. The monotonic increases in mortality risks of cerebrovascular diseases, sequelae of cerebrovascular disease and ischemic stroke were observed, without any discernible thresholds. Each 10 μg/m³ increase in NO₂ concentration was associated with increments of 3.62% [95% confidence interval (CI): 2.56%, 4.69%] for total cerebrovascular mortality, 4.29% (95% CI: 2.81%, 5.80%) for sequelae of cerebrovascular disease mortality and 4.30% (95% CI: 2.30%, 6.33%) for ischemic stroke mortality. No positive associations between NO₂ exposure and hemorrhagic stroke mortality were observed. A greater risk of NO₂ was observed in the warm season, in patients with less than 9 years of education and in those with single marital status. The effects of NO₂ were robust to mutual adjustment of co-pollutants.

Conclusions: Short-term exposures to NO₂ may increase the risk of cerebrovascular mortality, specifically for ischemic stroke and sequelae of cerebrovascular disease.

Keywords: air pollution; cerebrovascular diseases; hemorrhagic stroke; ischemic stroke; nitrogen dioxide; sequelae of cerebrovascular disease.

Abstract

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