Impact of Population Density on PM2.5 Concentrations: A Case Study in Shanghai, China

Shuaishuai Han,Bindong Sun

doi:10.3390/su11071968

Abstract

We examine the effects of the urban built environment on PM2.5 (fine particulate matter with diameters equal or smaller than 2.5 μm) concentrations by using an improved region-wide database, a spatial econometric model, and five built environment attributes: Density, design, diversity, distance to transit, and destination accessibility (the 5Ds). Our study uses Shanghai as a relevant case study and focuses on the role of density at the jiedao scale, the smallest administrative unit in China. The results suggest that population density is positively associated with PM2.5 concentrations, pointing to pollution centralization and congestion effects dominating the mitigating effects of mode-shifting associated with density. Other built environment variables, such as the proportion of road intersections, degree of mixed land use, and density of bus stops, are all positively associated with PM2.5 concentrations while distance to nearest primary or sub-center is negatively associated. Regional heterogeneity shows that suburban jiedao have lower PM2.5 concentrations when a subway station is present.

Highlights

With rapid urbanization, many cities in China are suffering from one of the worst levels of air pollution in the world [1,2,3]
There is a great disparity with the goals established in the “Shanghai 2040” program, which requires that the “PM2.5 concentration value must be controlled under 20 ug/m3”
This paper contributes to the literature on the links between the urban built environment and concentrations of PM2.5, one of the most noxious and common sources of air pollution associated with urban activity

Summary

Introduction

Many cities in China are suffering from one of the worst levels of air pollution in the world [1,2,3]. PM2.5, the main pollutant in China [4,5], accounted for 66.8% of the days when pollution levels were too high, and O3 and PM10 accounted for 16.9% and 15% each, respectively. People are more likely to engage in impulsive and risky behavior that they may later regret [13]. Such behavior may be rooted in short-term depression and anxiety. Transportation is closely related to the urban built environment through traffic infrastructure and the travel behaviors of residents [14,15]

Objectives

Methods

Results

Conclusion