Estimating historical <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:mrow><mml:msub><mml:mtext>PM</mml:mtext><mml:mn>2.5</mml:mn></mml:msub></mml:mrow></mml:math> exposures for three decades (1987–2016) in Japan using measurements of associated air pollutants and land use regression

Accurate estimation of historical PM2.5 exposures for epidemiological studies is challenging when extensive monitoring data are limited in duration. Here, we develop a national-scale PM2.5 exposure model for Japan using measurements recorded between 2014 and 2016 to estimate monthly means for 1987 through 2016. Our objective is to obtain accurate PM2.5 estimates for years prior to implementation of extensive PM2.5 monitoring, using observations...