RESEARCH ARTICLE

Future climate change decreases multi-pathway but increases respiratory human health risks of PAHs across China

¹ Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
² State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
³ College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China
⁴ National Climate Center, China Meteorological Administration, Beijing 100081, China
⁵ Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China
⁶ Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington L7S 1A1, Canada

^* Corresponding authors (emails: xiaxh@bnu.edu.cn (Xinghui Xia); yzhu16@sjtu.edu.cn (Ying Zhu))

Received: 4 February 2023
Revised: 30 June 2023
Accepted: 1 July 2023

Abstract

Future climate change will affect the environmental fate of hydrophobic organic contaminants (HOCs) and associated human health risks, yet the extent of these effects remains unknown. Here, we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons (PAHs), a group of HOCs, and assess future PAH-related human health risks under varying climate change scenarios over China at a continental scale. After removing the effects of PAH emission changes, we find that the total PAH concentrations would decrease in the air, freshwater, sediment, soil, and organisms, while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°C. Consequently, the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%, while the respiratory risks are projected to rise by 0.2%–5.8% in the future. However, the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69% compared with 2009 levels in China. Our study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.