The impacts of long-term exposure to PM2.5 on cancer hospitalizations in Brazil
Pei Yu, Rongbin Xu, Micheline de Sousa Zanotti Stagliorio Coêlho, Paulo Hilário Nascimento Saldiva, Shanshan Li, Qi Zhao, Ajay Mahal, Malcolm Sim, Michael J. Abramson, Yuming Guo
Abstract
Long-term exposure to PM2.5 has been linked to cancer incidence and mortality. However, it was unknown whether there was an association with cancer hospitalizations. Data on cancer hospitalizations and annual PM2.5 concentrations were collected from 1,814 Brazilian cities during 2002–2015. A difference-in-difference approach with quasi-Poisson regression was applied to examine State-specific associations. The State-specific associations were pooled at a national level using random-effect meta-analyses. PM2.5 attributable burden were estimated for cancer hospitalization admissions, inpatient days and costs. We included 5,102,358 cancer hospitalizations (53.8% female). The mean annual concentration of PM2.5 was 7.0 μg/m3 (standard deviation: 4.0 μg/m3). With each 1 μg/m3 increase in two-year-average (current year and previous one year) concentrations of PM2.5, the relative risks (RR) of hospitalization were 1.04 (95% confidence interval [CI]: 1.02 to 1.07) for all-site cancers from 2002 to 2015 without sex and age differences. We estimated that 33.82% (95%CI: 14.97% to 47.84%) of total cancer hospitalizations could be attributed to PM2.5 exposure in Brazil during the study time. For every 100,000 population, 1,190 (95%CI: 527 to 1,836) cancer hospitalizations, 8,191 (95%CI: 3,627 to 11,587) inpatient days and US$788,775 (95%CI: $349,272 to $1,115,825) cost were attributable to PM2.5 exposure. Long-term exposure to ambient PM2.5 was positively associated with hospitalization for many cancer types in Brazil. Inpatient days and cost would be saved if the annual PM2.5 exposure was reduced.