title: Internal migration and urbanization in China: impacts on population exposure to household air pollution (2000-2010).
abstract: Exposure to fine particles ≤ 2.5 μm in aerodynamic diameter (PM2.5) from incomplete combustion of solid fuels in household stoves, denoted household air pollution (HAP), is a major contributor to ill health in China and globally. Chinese households are, however, undergoing a massive transition to cleaner household fuels. The objective of the present study is to establish the importance of internal migration when it comes to the changing household fuel use pattern and the associated exposure to PM2.5 for the period 2000 to 2010. We also estimate health benefits of the fuel transition in terms of avoided premature deaths. Using China Census data on population, migration, and household fuel use for 2000 and 2010 we identify the size, place of residence, and main cooking fuel of sub-populations in 2000 and 2010, respectively. We combine these data with estimated exposure levels for the sub-populations and estimate changes in population exposure over the decade. We find that the population weighted exposure (PWE) for the Chinese population as a whole was reduced by 52 (36-70) μg/m(3) PM2.5 over the decade, and that about 60% of the reduction can be linked to internal migration. During the same period the migrant population, in total 261 million people, was subject to a reduced population weighted exposure (ΔPWE) of 123 (87-165) μg/m(3) PM2.5. The corresponding figure for non-migrants is 34 (23-47) μg/m(3). The largest ΔPWE was estimated for rural-to-urban migrants (138 million people), 214 (154-283) μg/m(3). The estimated annual health benefit associated with the reduced exposure in the total population is 31 (26-37) billion USD, corresponding to 0.4% of the Chinese GDP.
authors.affiliation: CICERO (Center for International Climate and Environmental Research, Oslo), PO Box 1129 Blindern, 0318 Oslo, Norway; Dept. of Chemistry, University of Oslo, PO Box 1033 Blindern, 0371 Oslo, Norway. Electronic address: Kristin.aunan@cicero.uio.no.
authors.forename: Kristin
authors.initials: K
authors.lastname: Aunan
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China.
authors.forename: Shuxiao
authors.initials: S
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000706:statistics & numerical data*; D003296:Cooking / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D006798:Housing / Q000706:statistics & numerical data; D063426:Human Migration / Q000706:statistics & numerical data*; D006801:Humans; D014507:Urbanization / Q000639:trends*
chemical_list: D000393:Air Pollutants
keywords: China; Household air pollution; Migration; PM(2.5); Population exposure; Urbanization