Heavy metal pollution characteristics and health risk assessment of dust fall related to industrial activities in desert steppes.

China's desert steppe is the transition zone between the grasslands in central China and the arid desert. Ecological security in this region has long been a subject of debate, both in the local and academic communities. Heavy metals and other pollutants are readily released during industrial production, combustion, and transportation, aggravating the vulnerability of the desert steppes. To understand the impact of industrial activiteis on the heavy metal content of dust fall in the desert steppe, a total of 37 dust fall samples were collected over 90 days. An inductively-coupled plasma mass spectrometer (NexION 350X) was used to measure the concentration of heavy metals Cu, Cd, Cr, Pb, Mn, Co, and Zn in the dust. Using comprehensive pollution index and multivariate statistical analysis methods, we explored the characteristics and sources of heavy metal pollution. We also quantitatively assessed the carcinogenic risks of heavy metals resulting from dust reduction with the help of health risk assessment models. The heavy metals' comprehensive pollution index values in the study area's dust fall were ranked as follows: Zn > Cd > Pb > Mn > Cu > Co > Cr. Among these, Zn, Cd, and Pb were significant pollution factors in the study area, and were affected by industrial production and transportation. The high pollution index was concentrated in the north of the research industrial park and on both sides of a highway. The seven heavy metals' total non-carcinogenic risk index (HI) values were ranked as follows: Mn > Co > Pb > Zn > Cr > Cu > Cd (only the HI of Mn was greater than one). Excluding Mn, the non-carcinogenic and carcinogenic risk index values of the other six heavy metals were within acceptable ranges. Previous studies have also shown that industrial transportation and production have had a significant impact on the heavy metal content of dust fall in the desert steppe.

[Construction and application of economy-pollution-environment three-dimensional evaluation model for district].

For deep analysis on the regional environmental economic system, the paper analyzes the mutual relation of regional economy development, environmental quality, environmental pollution, and builds the theoretical basis. Then, the economy-pollution-environment quality three-dimensional coupling evaluation model for district is constructed. It includes economic development level index, environmental pollution index, and environmental quality index. The model is a cube, which has spatialization and visualization characteristics. The model includes 8 sub cubes, which expresses 8 types of state, e. g. low pollution-inferior quality-low level of economic development etc. The model can be used to evaluate the status of region, divide development phase, analyze evolution trend etc. It has two ways including relative meaning evaluation (RME) and absolute meaning evaluation (AME). Based on the model, Yinchuan City in the Ningxia Hui Autonomous Region is used as an example for the empirical study. Using RME, compared with Guangzhou city, The result shows that the Yinchuan City has been a high pollution-low quality-low level of economic development state for a long period during 1996-2010. After 2007, the state changed to a high pollution-high quality-low level of economic development. Now, the environmental quality of Yinchuan city gets better, but pollutant discharge pressure is high, and tends to be the break point of high environment quality and low environment. With AME, using national standard, the Yinchuan City remains a high pollution-low quality-low level of economic development state during 1996-2010. Empirical research verifies that different target reference areas and relevant national standards have different main parameters, the evaluating result has an flexible range. The dimensionless data enhances the coupling of index. The data position in model increases the visibility to the environmental management decisions. The model improves mismatches of calculated data size, time asymmetry of spatial data, verification of the former multi-target coupling model.

[Development mechanism of concentrated poverty areas under the sustainable livelihood: The example of the development-restricted ecological district of Ningxia, Northwest China].

Livelihood capital has a close relationship with the income and expenditure of farmers' households. For example, the survival strategies of farmers' households are determined by it and it also influences regional development mechanisms and models. Under the analysis framework of sustainable livelihoods, this study evaluated farmers' livelihood capital, income, and expenditure, based on a participatory rural appraisal and a statistical method, in the development-restricted ecological district of Ningxia, decomposed into the nationality, terrain, and type of farmers' household. Further, by using an index of non-farm business households, the correlations between the livelihood capital and income with the expenditure of farmers' households and the index of non-farm business households were quantified to understand the mechanism of regional development. The results showed that livelihood capital was generally low in the study area. In particular, the livelihood capital of Hui nationality households was slightly higher than that of Han nationality households, that of river valley households was higher than that of mountain households, and that of combined occupation households and non-farm business households was significantly higher than that of agricultural households. Moreover, there was a significant positive correlation between the net annual income of farmers' households and the non-agricultural index, human capital, physical capital, and financial capital, while a significant negative correlation existed between net annual income and natural capital. These findings suggested that efforts were required to enhance the capacity of the non-agricultural index and the human, material, and other capital in the study area. They also served as a guideline for the circulation of peasants' means of production in order to accelerate the polarization of natural capital.