Estimation of particulate matter from visibility in Bangkok, Thailand

Lack of daily data on airborne particles has been a common problem in an air pollution research. To deal with this problem, a regression model was developed to estimate daily PM IO concentration using visibility in Bangkok from 1992 to 1997, based on 1092 visibility/PM IO pair- observations on low humidity days (humidity less than or equal to 76.5%). Visibility was significantly and inversely associated with PM10 (r =0.71), after adjusting for minimum temperature and winter indicator variable. The R-2 of the model was 0.51.