Acute exposure to sulfur dioxide and mortality: Historical data from Yokkaichi, Japan

ABSTRACT

We examined the association between acute exposure to sulfur dioxide (SO₂) and mortality, using historical data from 1972–1991 in Yokkaichi, Japan. We used a time-stratified case-crossover study design. We included all causes of death, excluding external causes, between 1972 and 1991 in Yokkaichi and the neighboring town, Kusu of the Mie Prefecture (N = 29,839). We obtained daily estimations of SO₂ concentrations during the study period. We then conducted conditional logistic regression analysis to examine association between SO₂ exposure and all-cause and cause-specific mortality. Exposure to SO₂ increased the risk of all-cause and cause-specific mortality in a non-linear manner. The relationship between SO₂ exposure and mortality outcomes remained after adjustment for co-pollutants such as particulate matter and nitrogen dioxide. Historical data from Yokkaichi, Japan, showed that SO₂ exposure increased the risk of all-cause and cause-specific mortality.

KEYWORDS:

• Air pollution
• Cardiovascular disease
• Epidemiology
• sulfur dioxide
• Respiratory disease
• Yokkaichi Asthma

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgments

We appreciate the valuable support from Ms. Saori Irie. She has no conflicts of interest to disclose.

Additional information

Funding

This study was supported by a Grant-in-Aid for Scientific Research (C), Nos 2646074606 and 17K0908509, from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). The sponsor was not involved in the study design; the collection, analysis, and interpretation of data; the writing of the report; or the decision to submit the paper for publication.