RESUMO
We constructed a multi-dimensional indicator system of "economic-social-ecological" with Huainan City, a typical coal resource-based city, as an example. The development of the system from 2002 to 2016 was examined by entropy weight method, coupled coordination development model and grey correlation coefficient. The coordinated development of multi-dimensional relationship in Huainan City was analyzed from a macro perspective. The results showed that the ecological subsystem had the largest weight, whose development level being U-shaped as a whole, first decreasing and then increasing, with significant impact on the comprehensive development level. The ternary coupling system was generally on the rise, with low absolute level of coupling. With the increases of ecosystem pressure, it would restrict the economic and social development and counteracted the coordinated development level. Economic development and economic vitality had a positive impact on social and ecological development, while social development had a greater impact on ecological subsystems. The improvement of environmental status had a supporting effect on economic and social development. In the transformation process of Huainan, it should maintain stable and rapid economic development, increase investment in social development and environmental pollution control, as well as pay attention to ecological support capacity to avoid restricting social and economic development.
Assuntos
Conservação dos Recursos Naturais , Ecossistema , China , Cidades , Carvão Mineral , EcologiaRESUMO
To analyze the pollution characteristics, source apportionment, and health risk of heavy metals (HMs) in street dust of Suzhou, China, 23 sampling sites were selected and periodically sampled for 12 months. A total of 276 samples were collected, and the concentrations of selected HMs (e.g., Cr, Cu, Fe, Mn, Pb, V, and Zn) were examined with an X-ray fluorescence spectrum analyzer. Results showed that the mean concentrations of Cr, Cu, Fe, Mn, Pb, V, and Zn in the street dust of Suzhou were 112.9, 27.5, 19941.3, 410.3, 45.2, 75.6, and 225.3 mg kg-1, respectively. Cr, Cu, Pb, and Zn exceeded their background values in local natural soils by 1.3-3.6-fold, whereas Fe, Mn, and V were all within their background values. However, enrichment factor analysis revealed that Cr, Cu, Mn, Pb, V, and Zn, especially Cr, Cu, Pb, and Zn, were enriched in Suzhou street dust. The HMs showed no significant seasonal changes overall, but spatial distribution analysis implied that the high values of Cr, Cu, Mn, Pb, V, and Zn were mainly distributed in areas with frequent human activities. Results of multivariate techniques (e.g., Pearson correlation, hierarchical cluster, and principal components analyses) suggested that Pb and Zn had complicated sources; Cu and V mainly originated from traffic sources; Fe and Mn mainly came from natural sources; and Cr was dominantly related to industrial district. Health risk assessment revealed that a single heavy metal might not cause both non-cancer and carcinogenic risks to local residents. Nevertheless, the sum of the hazard index of all selected HMs for children slightly exceeded the safety value, thereby implying that the HMs from Suzhou street dust can possibly produce significant risk to children. Cr was the priority pollutant in the study area because of its high concentration, high enrichment, and high contribution to non-cancer risk values.