Changes In Environmental Health Burden Caused By Population Migration

Over the past few decades,increasingly serious air pollution has occurred in China,which has led to an increasing number of premature deaths caused by fine particulate matter(PM_2.5).Previous studies have shown that air pollution from the process of population migration and rapid urbanization may have a significant impact on health burdens.In China,there is a scientific consensus on the severity of the environmental health burden caused by PM_2.5 pollution in different areas,but changes in the health burden associated with complex migration remain a significant challenge.Then there will be questions about what kind of migration would reduce environmental health burden?This study assessed the environmental health burden borne by people in each province of China and evaluated the changes in environmental health burden due to the intra-provincial urbanization migration and the inter-provincial migration process in the context of population migration trends.This study aims to provide a comprehensive assessment of changes in the environmental health burden of different types of migrants and to facilitate policy development to consider more humanely reducing the health burden of migrants.To guide people to pay attention to environmental health burden and choose to live in areas with reduced health burden as much as possible while meeting health and economic needs.First,we extracted the urbanization process in China using nighttime lighting data combined with ancillary data.Secondly,the environmental health burden of Chinese regions was assessed by the Integrated Exposure Response（IER）model.Then,the environmental health burden in urban and rural areas of each province were partitioned and the changes in environmental health burden due to the population migration process were evaluated in combination with the population migration paths in China.Finally,policy recommendations for health migration are proposed for different migration paths.（1）The nighttime lighting data were corrected for consistency and continuity,and mainland China was divided into eight zones according to economic development.The urbanization process of Chinese regions from 2000-2015 was extracted by threshold extraction method using nighttime lighting data combined with land use data in representative cities of the eight zones.（2）Using the Integrated Exposure Response（IER）model,premature mortality from four diseases,namely ischemic heart disease（IHD）,chronic obstructive pulmonary disease（COPD）,stroke（STK）and lung cancer（LC）,due to ambient concentrations of PM_2.5 was calculated as the environmental health burden borne.The environmental health burden in rural areas and urban areas in each province were also subdivided into statistics.（3）The intra-provincial urbanization migration and inter-provincial migration were counted and the changes in the environmental health burden of different migration routes was quantified to analyze which migration route migrants can bear less environmental health burden after migration.Our research showed that there was a roughly increasing trend in the environmental health burden borne by people in urban areas of China’s provinces from 2000-2015.The highest premature deaths reached 9.71 cases/km² in Tianjin in 2010.Intra-provincial urbanization migration is relatively stable in provinces west of the Hu Huanyong line,and relatively rapid in provinces east of the Hu Huanyong line.Large-scale migrants in the inter-provincial migration process mainly move from the Middle Reaches of the Yangtze River and Southwest China to the coastal areas in Eastern and Southern China,where they aspire to the economically developed coastal areas.In recent years,migration hotspots have gradually started to shift from coastal to inland areas,and provincial capitals in inland areas are becoming new migration destinations.Changes in premature deaths caused by intra-provincial urbanization migration and inter-provincial migration accounted for 48.40%～93.38%and 2.61%～34.52%of the total changes in premature deaths,respectively,with the former showing a decreasing trend and the latter an increasing trend.Moreover,by analyzing the changes in the environmental health burden associated with intra-provincial urbanization migration and inter-provincial migration,we found that few people needed to bear a higher environmental health burden after moving to Hainan,Tibet,Ningxia,Xinjiang,and Guangdong.In contrast,more than 50%of the people moving into Beijing,Liaoning,Shanghai,and Jiangsu had to bear a higher environmental health burden.Fujian and Zhejiang had a healthier environment than the other developed coastal provinces,and had a relatively low environmental health burden.Healthy migration needs to be an important factor in migratory migration considerations.This study can provide insights on how to reasonably plan healthy migration routes for developing countries that are experiencing mass population movements.Governments are guided to make reasonable strategies before non-healthy migration occurs,and to introduce health guide-type planning schemes to map out healthy migration routes for migrants.