From PM2.5 exposure to PM2.5 risks of inhaled dose in daily activities: Empirical evidence during workdays from guangzhou, China

Abstract

PM2.5 pollution poses a serious health risk to residents. In recent years, individual exposure to PM2.5 in daily activities has received much attention, but the impact of different activities at different times and spaces on PM2.5-triggered individual health risks has been ignored. In this paper, the residents' activity diaries and the data on the spatial-temporal changes in urban PM2.5 concentration obtained through the land-use regression model (LUR) were coupled to dynamically evaluate and analyze the characteristics of Guangzhou residents' PM2.5 inhaled dose in 24 h during workdays. The study showed that the residents' PM2.5 inhaled dose in daily activities is about 940.2 ± 94.5 μg (95% CI). This can better reflect the individual differences than the exposure to PM2.5 in daily activities. For every increase of 1 μg/day in the exposure to PM2.5, the inhaled dose will increase by 1.5 μg/day. The obvious spatial-temporal characteristics of PM2.5 inhaled dose are closely related to people's daily activities. The inhaled dose is high during the day and low at night, and the individual differences in inhaled dose in the commuting and leisure period is significant but is small during the working and sleeping period; if the individual inhaled dose exceeds the population's average for accumulated 7 h in a day, the probability of a high risk of the all-day inhaled dose increases significantly. The inhaled dose at the workplace and residence as well as in light physical activities accounts for a large proportion of the total. However, although the inhaled dose on roads and in other places, and moderate physical activities account for only a small proportion, it has a great impact on the risk level of the individual total inhaled dose. Therefore, the characteristics of PM2.5 inhaled dose and the individual activity should be considered, to propose targeted policies and suggestions from the perspective of both the government and individuals to reduce the health risk caused by PM2.5 pollution.