Long-term exposure to traffic-related air pollution and mortality in Shizuoka, Japan.
OBJECTIVE
The number of studies investigating the health effects of long-term exposure to air pollution is increasing, however, most studies have been conducted in Western countries. The health status of Asian populations may be different to that of Western populations and may, therefore, respond differently to air pollution exposure. Therefore, we evaluated the health effects of long-term exposure to traffic-related air pollution in Shizuoka, Japan.


METHODS
Individual data were extracted from participants of an ongoing cohort study. A total of 14,001 older residents, who were randomly chosen from all 74 municipalities of Shizuoka, completed questionnaires and were followed from December 1999 to March 2006. Individual nitrogen dioxide exposure data, as an index for traffic-related exposure, were modelled using a land use regression model. We assigned participants an estimated concentration of nitrogen dioxide exposure during 2000-2006. We then estimated the adjusted HR and their CI for a 10 microg/m(3) increase in exposure to nitrogen dioxide for all-cause or cause-specific mortality.


RESULTS
The adjusted HR for all-cause mortality was 1.02 (95% CI 0.96 to 1.08). Regarding cause-specific mortality, the adjusted HR for cardiopulmonary mortality was 1.16 (95% CI 1.06 to 1.26); in particular the adjusted HR for ischaemic heart disease mortality was 1.27 (95% CI 1.02 to 1.58) and for pulmonary disease mortality it was 1.19 (95% CI 1.02 to 1.38). Furthermore, among non-smokers, a 10 microg/m(3) increase in nitrogen dioxide was associated with a higher risk for lung cancer mortality (HR 1.30, 95% CI 0.85 to 1.93).


CONCLUSIONS
Long-term exposure to traffic-related air pollution, indexed by nitrogen dioxide concentration, increases the risk of cardiopulmonary mortality, even in a population with a relatively low body mass index and increases the risk of lung cancer mortality in non-smokers.
Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama city, Okayama Pref. 700-8558, Japan. yorichan@md.okayama-u.ac.jp
Takashi
T
Yorifuji
Saori
S
Kashima
Toshihide
T
Tsuda
Soshi
S
Takao
Etsuji
E
Suzuki
Hiroyuki
H
Doi
Masumi
M
Sugiyama
Kazuko
K
Ishikawa-Takata
Toshiki
T
Ohta
D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000209:etiology / Q000401:mortality; D008297:Male; D009026:Mortality; D009585:Nitrogen Dioxide / Q000032:analysis / Q000633:toxicity; D012120:Respiration Disorders / Q000209:etiology / Q000401:mortality; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*
D001335:Vehicle Emissions; D009585:Nitrogen Dioxide