[Ecological vulnerability of coal mining area: a case study of Shengli Coalfield in Xilinguole of Inner Mongolia, China].

In this paper, an ecological vulnerability evaluation index system for the Shengli Coalfield in Xilinguole of Inner Mongolia was established, which included 16 factors in ecological sensitivity, natural and social pressure, and ecological recovery capacity, respectively. Based on the expert scoring method and analytic hierarchy process (AHP), an ecological vulnerability model was built for the calculation of the regional ecological vulnerability by means of RS and GIS spatial analysis. An analysis of the relationships between land use and ecological vulnerability was also made, and the results were tested by spatial auto-correlation analysis. Overall, the ecological vulnerability of the study area was at medium-high level. The exploitation of four opencast areas in the Coalfield caused a significant increase of ecological vulnerability. Moreover, due to the effects of mine drained water and human activities, the 300 -2000 m around the opencast areas was turning into higher ecologically fragile area. With further exploitation, the whole Coalfield was evolved into moderate and heavy ecological vulnerability area, and the coal resources mining was a key factor in this process. The cluster analysis showed that the spatial distribution of the ecological vulnerability in the study area had reasonable clustering characteristics. To decrease the population density, control the grazing capacity of grassland, and regulate the ratios of construction land and cultivated land could be the optimal ways for resolving the natural and social pressure, and to increase the investment and improve the vegetation recovery coefficient could be the fundamental measures for decreasing the ecological vulnerability of the study area.

[Effect of heavy metals exposure on neurobehavioral function in welders].

OBJECTIVE: To explore the relationship between heavy metals exposure and neurobehavioral function impairment in welders. METHODS: The metals exposure in 82 welders and 51 operators were investigated with blood Pb, Cd and Mn via AAS, and the nervous impairment was evaluated with neurobehavioral core test battery (NCTB). RESULTS: Pb [(115.49 +/- 79.22) microg/L] and Cd [(3.67 +/- 3.19) microg/L] in welders were significantly higher than operators [(69.32 +/- 50.79) and (0.83 +/- 0.76) microg/L respectively] (P < 0.05). Welders had worse standard scores of NCTB 13 items such as depression-dejection than non-welders (P < 0.05). Significant difference of confusion-bewilderment and forward digit span in welders only existed in different groups of Pb and Mn, respectively. A dose-effect relationship was found between forward digit span and serum Mn level in welders. General linear regression analysis indicated that Pb exposure, Mn exposure and alcohol consume had negative relation with the loss of nervous system function. CONCLUSION: The nervous impairment in welders is attributed to occupational exposure to Pb and Mn, concomitantly.