Long-term exposure to fine particle matter and all-cause mortality and cause-specific mortality in Japan: the JPHC Study

• Main Authors: Norie Sawada (Author), Tomoki Nakaya (Author), Saori Kashima (Author), Takashi Yorifuji (Author), Tomoya Hanibuchi (Author), Hadrien Charvat (Author), Taiki Yamaji (Author), Motoki Iwasaki (Author), Manami Inoue (Author), Hiroyasu Iso (Author), Shoichiro Tsugane (Author)
• Format: Book
• Published: BMC, 2022-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1186/s12889-022-12829-2; 1471-2458
• Keywords: Particulate matter <2.5µg/m3 (PM2.5); Mortality; Low level exposure; Japan; Prospective study; Public aspects of medicine; RA1-1270
• Source: BMC Public Health, Vol 22, Iss 1, Pp 1-9 (2022)

Abstract Background Many epidemiological studies have reported the association between exposure to particulate matter and mortality, but long-term prospective studies from Asian populations are sparse. Furthermore, associations at low levels of air pollution are not well clarified. Here, we evaluated associations between long-term exposure to particulate matter <2.5 µg/m3 (PM2.5) and mortality in a Japanese cohort with a relatively low exposure level. Methods The Japan Public Health Center-based Prospective Study (JPHC Study) is a prospective cohort study of men and women aged 40-69 years in 1990 who were followed up through 2013 for mortality. In this cohort of 87,385 subjects who did not move residence during follow-up, average PM2.5 levels from 1998 to 2013 by linkage with 1-km2 grids of PM2.5 concentration were assigned to the residential addresses of all participants. To avoid exposure misclassification, we additionally evaluated the association between 5-year (1998-2002) cumulative exposure level and mortality during the follow-up period from 2003 to 2013 in 79,078 subjects. Cox proportional hazards models were used to calculate the association of long-term exposure to PM2.5 on mortality, with adjustment for several individual confounding factors. Results Average PM2.5 was 11.6 µg/m3. Average PM2.5 exposure was not associated with all-cause mortality or cancer and respiratory disease mortality. However, average PM2.5 was positively associated with mortality from cardiovascular disease (hazard ratio (HR) of 1.23 (95%CI=1.08-1.40) per 1-µg/m3 increase; in particular, HR in mortality from cerebrovascular disease was 1.34 (95%CI=1.11-1.61) per 1-µg/m3 increase. Additionally, these results using cumulative 5-year PM2.5 data were similar to those using average PM2.5 over 15 years. Conclusions We found evidence for a positive association between PM2.5 exposure and mortality from cardiovascular disease in a Japanese population, even in an area with relatively low-level air pollution.