Spatiotemporal Variations of Indoor PM2.5 Concentrations in Nanjing, China.

Jun Bi,Xiangjun Yin,Jinnan Wang,Zongwei Ma,Zhijuan Shao

doi:10.3390/ijerph16010144

Abstract

Indoor fine particulate matter (PM2.5) is important since people spend most of their time indoors. However, knowledge of the spatiotemporal variations of indoor PM2.5 concentrations within a city is limited. In this study, the spatiotemporal distributions of indoor PM2.5 levels in Nanjing, China were modeled by the multizone airflow and contaminant transport program (CONTAM), based on the geographically distributed residences, human activities, and outdoor PM2.5 concentrations. The accuracy of the CONTAM model was verified, with a good agreement between the model simulations and measurements (r = 0.940, N = 110). Two different scenarios were considered to examine the building performance and influence of occupant behaviors. Higher PM2.5 concentrations were observed under the scenario when indoor activities were considered. Seasonal variability was observed in indoor PM2.5 levels, with the highest concentrations occurring in the winter and the lowest occurring in the summer. Building characteristics have a significant effect on the spatial distribution of indoor PM2.5 concentrations, with multistory residences being more vulnerable to outdoor PM2.5 infiltration than high-rise residences. The overall population exposure to PM2.5 in Nanjing was estimated. It would be overestimated by 16.67% if indoor exposure was not taken into account, which would lead to a bias in the health impacts assessment.

Highlights

Due to the rapid urbanization and economic growth of China over the past few decades, the nation has experienced extremely high levels of air pollution, with PM2.5 as the dominant pollutant [1,2]
The results indicate that building type plays a significant role in the spatial distribution of indoor PM2.5 levels, which should be considered when exploring the internal differences in indoor air pollutants within a city
This study modeled the spatiotemporal variations of PM2.5 concentrations in residences in Nanjing with different building characteristics using the contaminant transport program (CONTAM) model

Summary

Introduction

Due to the rapid urbanization and economic growth of China over the past few decades, the nation has experienced extremely high levels of air pollution, with PM2.5 as the dominant pollutant [1,2]. Epidemiological studies have demonstrated the associations between PM2.5 exposure and a range of health effects, such as cardiovascular and respiratory diseases, cancer, and preterm birth [4,5,6,7]. People spend more than 80% of their time indoors [8,9,10], most air pollution health studies typically use a few fixed-site measurements of PM2.5 to represent human exposure concentrations [11,12,13], due to the lack of indoor PM2.5 concentration data. The difference between indoor and outdoor PM2.5 concentrations may bias health effect assessments in epidemiological studies [14,15,16].

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Results

Conclusion