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1.
刘飚  周玉萍 《干旱环境监测》1991,5(3):149-152,156
本文报道了新疆居民饮水中~(234)U、~(235)U和~(238)U比活度.它们的人口加权几何均值和算术均值分别为,~(234)U:113和186mBq/L;~(235)U: 3.0和 5.0mBq/L;~(238)U:65.9和108mBq/L.~(238)U的几何标准偏差为2.79.~(234)U/~(238)U活度比值为1.72.居民由饮水摄入~(234)U和~(238)U所受的有效剂量当量为13.5μSv/a,诱发1348万居民骨癌期望数约为1例/年.  相似文献   

2.
本文对新疆核试验场周围10个调查地区和5个对照地区采集180个土壤样品进行了~(90)Sr、~(137)Cs放射性含量的分析,结果表明,在各类土壤中~(90)Sr、~(137)Cs的放射性含量除黄粘土与潮土、盐土及风沙土有非常显著性差异外(p<0.01),其余各类土壤之间均无显著性差异(p>0.05)。~(90)Sr、~(137)Cs在各类土壤中的垂直分布随深度的增加而含量减少。0~10Cm剖层中的~(137)Cs含量高于~(90)Sr的含量,而在10~20Cm和20~30Cm剖层中则~(90)Sr含量高于~(137)Cs的含量。其迁移速度,潮土、盐土、风沙土之间看不出多大的差别,但黄粘土较慢。~(90)Sr、~(137)Cs在各类土壤中均呈现出~(90)Sr的迁移比~(137)Cs快的总趋势。  相似文献   

3.
一、状况 表1列出了建材成品中~(226)Ra、~(232)Th和~(40)K的含量,并按苏联、波兰和我国的计算式计算了总活性比值。 建材成品的~(226)Ra含量变化范围为32~76Bq kg~(-1),平均为51.6Bq kg~(-1);~(232)Th  相似文献   

4.
报道了兰州市区空气中天然放射性核素^238U、^232Th、^226Ra浓度的估算结果。根据UNSCEAR1982年报告,假定空气中^238U、^232Th、^226Ra放射性核素浓度来源于土壤微粒的再悬浮,则可通过测量兰州市区土壤中天然放射性核素比活度和利用近几年空气中TSP含量资料的估算来确定上述放射性核素对环境污染的现状。结果表明,^238、^232Th、^226Ra浓度的多年平均值分别为2  相似文献   

5.
本文介绍了用Ge(Li)γ谱测定山东省13种农产品及其相应土壤中~(238)U、~(226)Ra、~(232)Th,~(40)K和~(137)Cs放射性植素的含量,分别计算了浓积系数,结果表明,有些农作物对某些核素具有特殊的浓积作用  相似文献   

6.
采用高纯锗γ谱仪测量连云港田湾海域表层沉积物中7种放射性核素含量水平,分析其粒度特征和放射性核素分布特征,并与我国其他海域作对比。结果表明,该海域以细颗粒沉积物为主,以悬移质泥沙搬运为主要沉积模式;沉积物中~(210)Pb、~(238)U、~(228)Ra、~(40)K、~(226)Ra、~(228)Th、~(137)Cs的测定均值分别为50.89 Bq/kg、39.98 Bq/kg、46.70 Bq/kg、898.72 Bq/kg、25.20 Bq/kg、51.65 Bq/kg、2.01 Bq/kg,虽然比活度变化较大,但总体处于一个水平;每个采样点位各核素出现的极大值有所不同,与离岸距离无明显关系;铀系、钍系衰变系列核素的放射性均呈现出一定的衰变不平衡性;沉积物中~(40)K含量明显高于我国其他海域,~(137)Cs含量明显低于渤海湾,总体高于其他南部海域,与以往研究结论基本一致。  相似文献   

7.
本文研究了三溴偶氮肿(TBA)与钙、镁的显色反应,结果表明:在平平加存在下,PH10.4硼酸-氢氧化钠缓冲体系中,钙、镁与TBA都形成1:2稳定的紫色络合物,以490nm为参比波长,620nm为测定波长,用双波长分光光度法测得ε_(490-620)~(Ca)=7.21×10~3l·mol~(-1)·cm~(-1),ε_(490-620)~(Ca)=2.55×10~4l·mol~(-1)·cm~(-1),比尔定律范围是0-35μgmg/25ml,0-40μgCa/25ml,无平平加时ε_(490-620)~(Mg)=6.61×10~3l·mol~(-1)·cm~(-1),ε_(490-620)~(Ca)=2.3×10~4。根据有无平平加时测定络合物吸光度的差异,利用公式法求得Ca,Mg含量,方法简便、快速、可靠。  相似文献   

8.
洪泽湖硝基苯类化合物的污染特征   总被引:2,自引:2,他引:0       下载免费PDF全文
对洪泽湖水质、底泥及水生生物样品10种硝基苯类化合物的浓度进行了测定,水样中总硝基苯类化合物的含量在0.179~5.17μg/L,北部湖区和南部湖区的总硝基苯类化合物的浓度较高,其中成河北(S7)的浓度最高。底泥中的含量在0.137~4.50μg/kg,北部湖区及出湖口附近形成一个硝基苯类化合物的污染带,其中成河东(S6)的浓度最高。水生生物体内的总硝基苯含量按鲫鱼、白鱼、泥鳅、龙虾、河蚌、螺蛳依次升高。  相似文献   

9.
在离子色谱法中用碳^18小柱预处理有机污染水样   总被引:1,自引:0,他引:1  
在离子色谱法中用碳~(18)小柱预处理有机污染水样薛光璞,牛星梅(南京市环境监测中心站210013)离子色谱法测定无机阴离子快速、准确、特异性好,在环境监测中得到广泛应用。但河流、湖泊受到有机化工废水污染后,地表水中含的有机污染物对该方法的测定干扰很大,...  相似文献   

10.
冷原子荧光法测定土壤中总汞的研究   总被引:1,自引:0,他引:1  
土壤中总汞含量与土壤的形成过程,利用情况以及环境变迁有密切关系.底土中总汞的质量份数含量通常在2~10×~(-9)范围,而表土则高达10~10×10~(-9).土壤中总汞含量差异如此悬殊,因此其测定方法应视含量而加以选择,常用的双硫腙比色法,无焰原子吸收法和冷原子荧光法,均适于高含量RK汞的测定.但由于试样中共存元素干扰严重,必须进行繁琐的化学预处理,给测定带来麻烦.我们针对江苏省站提供的两种总汞量保证值在5~16×10~(-9)范围  相似文献   

11.
对渭河干流(宝鸡段)表层沉积物中重金属Cu、Zn、Pb含量进行了调查,用潜在生态危害系数法对其污染水平进行了评价,并与松花江(吉林市段)、淮河(江苏段)、长江(下游)、苏州河、珠江(广州段)5条河流表层沉积物中Cu、Zn、Pb的含量做了对比研究。结果表明,3种重金属元素平均含量均超出相应的土壤背景值,出现了一定程度上的富集;生态危害系数均〈40,属轻微生态危害。重金属含量水平在国内诸河中处于中间位置。  相似文献   

12.
Human activities are a key driver of air pollution, so it is hardly surprising that celebrations affect air quality. The use of fireworks contributes to high particulate concentrations in many parts of the world, with the Chinese Lunar New Year (spring festival) particularly noticeable, as firecrackers are traditionally used to drive off evil spirits. Fireworks lead to short-term peaks in the concentration of PM10, PM2.5 and SO2. Regulatory actions that restrict the use of fireworks have been evident in China since the 1990s. This paper investigates the particulate concentrations in nine Chinese cities (Beijing, Chengdu, Chongqing, Tianjin, Xi’an, Nanjing, Shanghai, Guangzhou and Shenzhen, along with Hong Kong (a Special Administrative Region) and Taipei and Kaohsiung (Taiwan) with a particular focus on the celebrations of 2015. Extremely high concentrations of particulate matter were observed, with some sites revealing peak PM10 concentrations in excess of 1000 μg m?3 in the early hours of the New Year. In Beijing, Tianjin and Chongqing, the activities caused high particulate matter concentrations at most sites throughout the city. These peaks in particulate load in the early hours of Chinese New Year do not appear to be closely related to meteorological parameters. However, in cities where fireworks appear to be better regulated, there are fewer sharp pollution peaks just after midnight, although lowered air quality can still be found in the outer parts of some cities, remote from regulatory pressures. A few cities seem to have been effective at reducing the impact of the celebrations on air quality, with Nanjing a recent example. An increasing focus on light displays and electric lanterns also seems to offer a sense of celebration with much reduced impacts on air quality.  相似文献   

13.
In order to investigate the characteristic of optical properties of Asian dust particles, the atmospheric aerosol vertical profile was measured with the multi-wavelength LIDAR system, at the Gosan super site (33 degrees 17'N, 126 degrees 10'E) in Jeju Island, Korea, during the ACE-Asia intensive observation period, 11 March-4 May 2001. An air mass backward trajectory analysis, using Hysplit-4, was carried out to track the aerosol plume, with high mass loading, from the Chinese desert regions during the period of Asian dust storm events. Vertical atmospheric aerosol profiles on three major Asian dust storm event days, 22 March and 13 and 26 April 2001, have been analyzed. The LIDAR-derived aerosol optical depth values were compared with those measured by a collocated sunphotometer.  相似文献   

14.
本文对国外3种名烟、国内畅销47种烟及新疆7种烟进行研究。结果表明:香烟中~(210)Po和~(210)Pb平衡系数为0.801;烟雾中~(210)Po和~(210)Pb比值为1.15,表明烟雾中~(210)Po量比~(210)Pb多;主流烟雾中~(210)Po占整支烟~(210)Po量的12.93%,而~(210)Pb占8.17%;烟咀阻留~(210)Po效率为(52.0±10.7)%,阻留~(210)Pb效率为(58.3±7.2)%;估算了每日吸一盒烟的人,20年肺和支气管剂量当量,约1.38 ×10~(-2)S_v。  相似文献   

15.
This study investigated the extent of heavy metal accumulation in leaf vegetables and associated potential health risks in agricultural areas of the Pearl River Delta (PRD), South China. Total concentrations of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr) and arsenic (As) were determined in 92 pairs of soil and leaf vegetable (flowering Chinese cabbage, lettuce, pakchoi, Chinese cabbage, loose-leaf lettuce, and Chinese leaf mustard) samples collected from seven agricultural areas (cities). The bioconcentration factors (BCF) of heavy metals from soil to vegetables were estimated, and the potential health risks of heavy metal exposure to the PRD residents through consumption of local leaf vegetables were assessed. Results showed that among the six leaf vegetables, pakchoi had the lowest capacity for heavy metal enrichment, whereas among the five heavy metals, Cd had the highest capacity for transferring from soil into vegetables, with BCF values 30-fold those of Hg and 50-fold those of Cr, Pb and As. Sewage irrigation and fertilization were likely the main sources of heavy metals accumulated in leaf vegetables grown in agricultural areas of the PRD region. Different from previous findings, soil pH had no clear effect on metal accumulation in leaf vegetables. Despite a certain degree of metal enrichment from soil to leaf vegetables, the PRD residents were not exposed to significant health risks associated with consumption of local leaf vegetables. Nevertheless, more attention should be paid to children due to their sensitivity to metal pollutants.  相似文献   

16.
Agricultural decision-making to control nonpoint source (NPS) water pollution may not be efficiently implemented, if there is no appropriate cost-benefit analysis on agricultural management practices. This paper presents an interval-fuzzy linear programming (IFLP) model to deal with the trade-off between agricultural revenue, NPS pollution control, and alternative practices through land adjustment for Wuchuan catchment, a typical agricultural area in Jiulong River watershed, Fujian Province of China. From the results, the lower combination of practice 1, practice 2, practice 3, and practice 7 with the land area of 12.6, 5.2, 145.2, and 85.3 hm2, respectively, could reduce NPS pollution load by 10 %. The combination yields an income of 98,580 Chinese Yuan/a. If the pollution reduction is 15 %, the higher combination need practice 1, practice 2, practice 3, practice 5, and practice 7 with the land area of 54.4, 23.6, 18.0, 6.3, and 85.3 hm2, respectively. The income of this combination is 915,170 Chinese Yuan/a. The sensitivity analysis of IFLP indicates that the cost-effective practices are ranked as follows: practice 7 > practice 2 > practice 1 > practice 5 > practice 3 > practice 6 > practice 4. In addition, the uncertainties in the agriculture NPS pollution control system could be effectively quantified by the IFLP model. Furthermore, to accomplish a reasonable and applicable project of land-use adjustment, decision-makers could also integrate above solutions with their own experience and other information.  相似文献   

17.
中、英、美污染场地风险评估导则异同与启示   总被引:3,自引:0,他引:3  
近年来,随着国家"退二进三"旧城改造政策的实施,全国几乎所有的大中城市正面临着大批多种污染行业企业的关闭和搬迁,这些搬迁企业遗留场地都存在着不同程度的环境与健康风险.开展定量评估人体健康与生态环境风险是建立我国工业污染场地管理体系不可缺少的技术手段,也是适合我国国情并走向可持续性(绿色)土壤与地下水修复及综合环境管理的...  相似文献   

18.
Heavy metal pollution is an increasing environmental problem in Chinese regions undergoing rapid economic and industrial development, such as the Pearl River Delta (PRD), southern China. We determined heavy metal concentrations in surface soils from the PRD. The soils were polluted with heavy metals, as defined by the Chinese soil quality standard grade II criteria. The degree of pollution decreased in the order Cd?>?Cu?>?Ni?>?Zn?>?As?>?Cr?>?Hg?>?Pb. The degree of heavy metal pollution by land use decreased in the order waste treatment plants (WP)?>?urban land (UL)?>?manufacturing industries (MI)?>?agricultural land (AL)?>?woodland (WL)?>?water sources (WS). Pollution with some of the metals, including Cd, Cu, Ni, and Zn, was attributed to the recent rapid development of the electronics and electroplating industries. Cd, Hg, and Pb (especially Cd) pose high potential ecological risks in all of the zones studied. The soils posing significantly high and high potential ecological risks from Cd covered 73.3 % of UL, 50 % of MI and WP land, and 48.5 % of AL. The potential ecological risks from heavy metals by land use decreased in the order UL?>?MI?>?AL?>?WP?>?WL?>?WS. The control of Cd, Hg, and Pb should be prioritized in the PRD, and emissions in wastewater, residue, and gas discharges from the electronics and electroplating industry should be decreased urgently. The use of chemical fertilizers and pesticides should also be decreased.  相似文献   

19.
Several polycyclic aromatic hydrocarbons (PAHs), including those which are carcinogenic, have been detected in rougan, a traditional Chinese barbecued pork dish. The food samples were cleaned up by caustic digestion, solvent extraction, liquid-liquid partition, and column chromatography. The determination was carried out using capillary gas-chromatography with a flame ionization detector. A 25-m HP-1 capillary column was used. Fluorene, phenanthrene, anthracene, benzo[a]anthracene, chrysene and benzo[k]fluoranthene were detected in three of the five samples within the range of 3-17 ng/g. Fluoranthene and pyrene were detected in only two of the samples at similar levels. Two potent carcinogenic compounds, benzo[a]pyrene and benzo[b,j,k]fluoranthene, were not detected in any of the samples. No detectable PAHs have been found in meat cooked without the direct contact of food with flame and smoke. In barbecuing over an open charcoal fire, animal fat and juices dripping onto the open fire probably enhanced the formation of PAHs.  相似文献   

20.
Food cooking using liquefied petroleum gas (LPG) has received considerable attention in recent years since it is an important source of particulate air pollution in indoor environments for non-smokers. Exposure to organic compounds such as polycyclic aromatic hydrocarbons (PAHs) contained in particles is of particular health concern since some of these compounds are suspected carcinogens. It is therefore necessary to chemically characterize the airborne particles emitted from gas cooking to assess their possible health impacts. In this work, the levels of fine particulate matter (PM(2.5)) and 16 priority PAHs were determined in three different ethnic commercial kitchens, specifically Chinese, Malay and Indian food stalls, where distinctive cooking methods were employed. The mass concentrations of PM(2.5) and PAHs, and the fraction of PAHs in PM(2.5) were the highest at the Malay stall (245.3 microg m(-3), 609.0 ng m(-3), and 0.25%, respectively), followed by the Chinese stall (201.6 microg m(-3), 141.0 ng m(-3), and 0.07%), and the Indian stall (186.9 microg m(-3), 37.9 ng m(-3), and 0.02%). This difference in the levels of particulate pollution among the three stalls may be attributed to the different cooking methods employed at the food stalls, the amount of food cooked, and the cooking time, although the most sensitive parameter appears to be the predominant cooking method used. Frying processes, especially deep-frying, produce more air pollutants, possibly due to the high oil temperatures used in such operations. Furthermore, it is found that frying, be it deep-frying at the Malay stall or stir-frying at the Chinese stall, gave rise to an abundance of higher molecular weight PAHs such as benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene whereas low-temperature cooking, such as simmering at the Indian stall, has a higher concentration of lower molecular weight PAHs. In addition, the correlation matrices and diagnostic ratios of PAHs were calculated to determine the markers of gas cooking. To evaluate the potential health threat due to inhalation exposure from the indoor particulate pollution, excess lifetime cancer risk (ELCR) was also calculated for an exposed individual. The findings suggest that cooking fumes in the three commercial kitchens pose adverse health effects.  相似文献   

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