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Polycyclic aromatic hydrocarbons (PAHs) are major pollutants in urban areas, and thus present a high risk to the resident health. However, studies on local PAH emissions and associated health risks related to urbanization are scarce. Here, the concentrations of PAHs were determined in 57 surface soil samples obtained from two rural districts in 2018 in Tianjin, China. The sources, risks, and the linkage between urbanization and PAH contamination of soils in 2018 were compared with PAH data in 2001 from a previous study to investigate the changes induced by urbanization. Results show an increase in PAH concentrations from 2001 to 2018, with in particular the predominance of anthracene and dibenz[a,h]anthracene. The major sources of soil PAHs changed from coal combustion 32.9%, petroleum sources 32.1%, and traffic sources 22.1% in 2001, to traffic sources 63.7%, and petroleum and biomass combustion 18.7% in 2018. The carcinogenic risk of soil PAHs to residents also increased from safe level to low level, and dermal contact was the prevailing pathway of PAH exposure. The increase in cancer risk is mainly due to the changes in PAH sources. [ABSTRACT FROM AUTHOR]

Urbanization-related human activities, such as population aggregation, rapid industrial expansion, and intensified traffic, are key factors that impact local polycyclic aromatic hydrocarbon emissions and their associated health risks. Consequently, regions with varying degrees of urbanization within a megacity may exhibit diverse spatiotemporal patterns in the presence and distribution of soil polycyclic aromatic hydrocarbons, resulting in different levels of ecological risks for local inhabitants following the same period of development. In this study, we measured the concentrations of 16 polycyclic aromatic hydrocarbons in soil samples collected from industrial district and rural district in Tianjin (China) in 2018, and compared with polycyclic aromatic hydrocarbon data in 2001 from a previous study to characterize these regional variations in occurrence, source, and human risk of polycyclic aromatic hydrocarbons induced by urbanization with time and space. The results indicate the 20-year rapid urbanization and industrialization has differentially affected the composition, distribution and sources of polycyclic aromatic hydrocarbons in soils from different economic functional zones in Tianjin. Additionally, its impact on health risks in rural district appeared to be more significant than that in industrial district. • Urbanization had different effects on industrial and rural soil PAHs. • Regional socioeconomic patterns and residential behaviors influenced local PAH source profiles. • Risk regions and affected population were estimated quantitatively. • Urbanization-related impact on cancer risks in rural district seemed more notable. [ABSTRACT FROM AUTHOR]

Abstract The developing technology of wavelet analysis offers a valuable tool in mitigating many of the limitations of earlier studies of housing price dynamics. This paper applies wavelet analysis to five first-tier cities in China to study housing price changes over time, to decompose housing prices into their trend and cycle components, and to explore co-movement and lead-lag relationships among these cities. We find the average cycle for all five cities to be 3.25 years, which is much shorter than the housing cycles observed in the United States. When we examine the cyclical lead-lag relationships among these cities, we find that during the 2008–2011 period, Shenzhen led Beijing, which led Guangzhou, which led Shanghai, and finally Tianjin followed. However, during the 2011–2014 period, the lead-lag relationships changed to Tianjin leading Shenzhen, then Shanghai, then Beijing, and finally Guangzhou. Although we generally observe a strong co-movement among the city pairs, the co-movement between Tianjin and each of the remaining four cities is weak. The weaker correlation between Tianjin and other cities indicates that real estate investors in these other four cities can improve their risk-return performance by adding Tianjin properties to their portfolios. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) in urban soils are of increasing concern because of their potential toxicity and persistence. However, there is limited information about PAHs in Tianjin coastal new region, although it is an important economic and industrial center in Northern China. Here we determined the concentrations of PAHs in 210 surface soil samples collected from this region according to administrative divisions covering Han'gu district, Tanggu district, and Dagang district, to evaluate their contamination and potential cancer risks. The concentrations of 16 PAHs ranged from 58.2 to 9160 ng g−1, and the highest concentration was found in Han'gu district. According to the incremental lifetime cancer risk (ILCR) model, the soils from Han'gu district and Dagang district posed a moderate carcinogenic risk to residents, and dermal contact was the main exposure pathway. Besides, ILCRs for children through ingestion were comparable to those for adults but apparently higher than adolescents, while ILCRs of dermal contact for adults were higher than children and adolescents. Comparisons between the layout of industrial zones and the distributions of PAHs as well as ILCRs indicate that PAHs accumulating in soils and then incurring risk areas is partly controlled by the economic and industrial structure. Image 1 • PAH concentrations in soils are comparable between 2001 and 2018 in Tianjin. • Dermal contact is the chief exposure pathway for cancer risk to residents. • Children and adults are sensitive subpopulation through ingestion and dermal contact respectively. • Distributions of PAHs and cancer risk areas are closely related to the industrial structure. The distributions of PAHs and incurred cancer risk areas are closely related to the economic and industrial structure. Dermal contact is the chief exposure pathway for cancer risk to residents. [ABSTRACT FROM AUTHOR]

With rapid growth of the vehicle population, urban passenger transport in China is largely responsible for increases in energy consumption, greenhouse gas (GHG) emissions, and also atmospheric pollutants (NO x , CO, HC, PM). In this paper, we first develop an urban passenger transport energy saving and emission reduction potential evaluation model using the “Long Range Energy Alternatives Planning (LEAP)” tool; and then take Tianjin city as an empirical case to evaluate the reduction potential of final energy consumption, GHG emissions and pollutants emissions of Tianjin’s urban passenger transport sector between 2010 and 2040 under four scenarios, i.e. BAU (business as usual) scenario, PP (the 12th five-year plan policy) scenario, CP (comprehensive policy) scenario and HP (hybrid policy of PP and CP) scenario. The results show that due to the public transport promotion, energy consumption and CO 2 emissions in 2040 can be reduced by 22% and 22.6% in the PP scenario, compared to BAU. The largest reductions in energy consumption, CO 2 and atmospheric pollutants emissions can be achieved under CP scenario, in which vehicle population regulation is the most effective to be implemented. Emissions standard regulation is the most effective measure to reduce atmospheric pollutant emissions in all the scenarios and green energy promotion is especially effective to reduce NO x and PM. [ABSTRACT FROM AUTHOR]