Advanced Materials Research Vols. 1092-1093

Abstract: The natural sedimentation method was employed to monitor air microbes at eighteen different public places. There are significant differences of microbial concentration in air among the functional places in Tianjin (p<0.05). The density of bacteria, fungi and total microbes were 1.22×10⁴ CFU/m³, 2.6×10³ CFU/m³, and 1.48×10⁴ CFU/m³, respectively. There are 18 sampling sites, within which extremely and seriously polluted area accounted for 11%, and moderately and slight polluted area accounted for 6%, and clean and relatively clean area equally accounted for 33%. The industrial and transport regions were the most seriously contaminated district by airborne microbes in Tianjin, and our study here indicates that routine monitoring of airborne microorganisms quality plays a critical role in preventing outbreak of airborne diseases and detecting source of microbial pollution.

Abstract: Guangxi Nandan county is a typical karst geological area, groundwater is rich, rich Tibetan non-ferrous metals. In order to study the risk of groundwater pollution on human health in mining area of Nandan County, base on the investigation and monitoring, The results of groundwater environment risk assessment of mine area of Nandan County show that water environmental health risk of No.5 belong to the minimum level, No.1, No. 2, No.3 and No.7 of four monitoring points is low risk,No.4 and No.6 for medium risk, No.8 as high risk.The health risk average value caused by toxic substances to individual person per year is 4.76×10^-5a^-1, which is less than the maximum acceptable level5×10^-5a^-1recommended by ICRP. The groundwater environmental health risks, mainly comes from chemical carcinogens arsenic (As), accounted for the average health risk (R_t) 99.998%,non carcinogenic health risk accounted for only 0.002%, almost negligible, therefore,stricter governing of chemical carcinogens is an effective way to reduce the health risk of groundwater pollution in mining area of Nandan County.

Abstract: The local-scale atmospheric dispersion model with complex conditions based on the 3D boundary layer model for atmospheric dispersion over complex terrain was developed, and coupled the urban canopy model of Peking University. The comparing results of fields experiment and numerical simulation revealed that the relative errors on hazard depth were 5.7% and 7.4% respectively at two threshold doses. A series of studies were completed on numerical simulation under the various conditions. The dispersion of pollutants influenced by complex terrains, buildings and non-uniform underlying surface were simulated. The numerical simulation results revealed that the chemical hazard depth was distributed from 60m to 772m for the Haerbaling Japanese Abandoned Chemical Weapons destruction.

Abstract: According to environmental lead exposure data and dietary survey data of lead and zinc smelting area,blood lead levels of children (2~7years old) in study area were predicted with IEUBK model. The children's blood lead concentration predicted value was compared with the corresponding measured value,by comparing the differences, measured the prediction ability of model. The results showed that predicted value and measured value of 2~7 years old children's blood lead concentration in A village were higher than the other villages, they were 33.5μg/dL,30.8μg/dL, respectively; predicted value and measured value of 2~7 years old children's blood lead concentration in I village were the lowest among all villages,they were14.5μg/dL,13.1μg/dL, respectively.By paired T-test showed that the predicted value were higher than the measured value about 1.4~3.4μg/dL,model calculation results slightly overestimated the children's blood lead level.But in general, the predicted value and measured value had a good consistency,through the model prediction could better reflect the children's blood lead levels in the study area.

Abstract: Grey forecast can master the developing law of system through dealing with incomplete information of system at present. On the basis of actual data of Feng Feng Coal Mine, the grey forecasting model for coal mine accidents due to human factor in Feng Feng by using the grey system theory in this paper, it is shown that models which are built have good precisions. Safety and production of Feng Feng Coal Mine are forecasted by using grey forecasting models which are built. The results show that the forecasting models will help coal mines to forecast accidents due to human factor next year and generally tally with development tendency of Feng Feng Coal Mine.

Abstract: With the increase of urban electromagnetic radiation source, electromagnetic environment pollution which poses a threat to the health of the residents is increasingly worse, there exists a controversy to the safety limit. In order to master the basic information about urban electromagnetic radiation source of major cities in Jilin, the statistical analysis of environmental comprehensive field monitoring data is conducted in Jilin province’s major cities, Changchun, Yanji and Siping ,the result shows that the electric field intensity of the environmental electromagnetic radiation in three cities is below China electromagnetic radiation safety standard. Then according to the research situation at home and abroad , combining the practical situation of Jilin province, this article discusses the protection standard of environmental electromagnetic radiation and provides the suggested values of the safety threshold limit of electromagnetic radiation .

Abstract: Certain heavy metal contaminated site is taken as the example to determine whether the four pollutants, namely As, Cr, Cr (VI) and Ni, exceed the screen levels of soil pollutants for health risk assessment of residential lands specified in Screening Levels for Soil Environmental Risk Assessment of Sites (DB11/T 811-2011) through sampling analysis. In allusion to the main exposure pathway of sensitive population, RBCA model is adopted to assess the health risk of this site, and the results show that the carcinogenic risks of Cr (VI) and As in the three layers of tested sample soils both exceed 10^-6 with Cr (VI) and Ni in the first and second layers have larger non-carcinogenic quotient. At last, 10^-6 and 1 are regarded as acceptable risk levels, then the RBCA model is used to adversely deduce the pollution remediation target values of the site, and the calculated results are compared with Grade A standards specified in the Assessment Standards for Soil Environmental Quality of Exhibition Lands (Provisional) (HJ350-2007). Then the background values of local soil environment for correction and finally the relatively rational soil pollution remediation target values have been obtained: Cr (VI): 2mg•kg^-1, As: 20mg•kg^-1, Ni: 50mg•kg^-1, Cr: 190 mg•kg^-1.

Abstract: Asbestos collectively refers to a set of naturally existing silicate minerals with fibrous structures, and is a natural mineral in fibrous forms that was originally serpentines or amphiboles. Because of its properties such as resistance to heat, chemical resistance and corrosion; tensile strength; sound absorption; and affordable prices, it had been widely used as building materials, fire resistant and retardant, thermal and heat insulation, sound absorbent, and electrical insulation. Since the prolonged inhalation of asbestos can cause serious illnesses such as lung cancer, mesothelioma, and asbestosis after an incubation period of 20 to 40 years, the mineral was classified as Group 1 carcinogen by the International Agency for Research on Cancer. In Korea, asbestos-containing construction materials had been widely used until asbestos was added to the hazardous substance requiring permission for use by the Occupational Safety and Health Act, and use of asbestos was totally banned in February 2009. This survey was conducted with 45 buildings to assess asbestos-containing materials used by usage of building. It was found that asbestos-containing construction materials were used in 27 buildings out of 45 buildings surveyed.

Abstract: The oil spill accidents from ships are sudden random events which usually great loss when one happens. In order to response to these sporadic events and prepare equipments in advance, there is a need to estimate the oil spill accident probability and its quantity in a port. This paper mainly takes Zhoushan Port as the example and uses the discrete convolution method to calculate the oil spill probability of the single ship, the joint oil spill probability and its quantity, thus to provide a support for the preparation for the government.

Abstract: In this paper, the mechanism of radio frequency (RF) causing fire and explosion directly and indirectly was recommended, studies of RF risks in flammable and explosive environments were summarized, some problems in RF risk researches recently were discussed, study prospects of RF risks in flammable and explosive environments were analyzed. The fact that the mechanisms and conditions of RF igniting combustible gases should be researched by more deeply theories and technological means, and that RF security standards should be laid down and a complete and precise RF security assessment system should be established in flammable and explosive environments was put forward.