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991.
Abstract

Cooking of foods and the burning of biomass and fossil fuels in stoves are the main sources of cooking fumes, with carbon black and polycyclic aromatic hydrocarbons as main components. The toxicity of carbon black and polycyclic aromatic hydrocarbons has been well studied individually, but the combined toxicity is much less understood. Carbon black can adsorb benzo(a)pyrene to form a complex which displays an altered physical form which in this study has been constructed to simulate particles in the cooking fumes and explore the combined toxic effect on rat alveolar macrophages. The complex-induced cell apoptosis and blocked cell autophagy flux compared with both individually. The mechanism of toxicity may be by intracellular reactive oxygen species generation, impairing the mitochondrial membrane potential and activating apoptosis signaling pathways.  相似文献   
992.
993.
Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a “body burden” of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a “holistic” measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical “systems biology” approach to risk evaluation of complex environmental exposures.  相似文献   
994.
黄河中下游水体中多环芳烃的分布及来源   总被引:15,自引:5,他引:10  
对小浪底至山东东明段黄河干、支流水、悬浮物和沉积物进行了采样分析.结果表明,干流水相∑15PAHs浓度范围为179~369ng/L,其中除焦巩桥外其它断面苯并(a)芘均超过国家饮用水标准;支流水相浓度均高于相应干流,尤其是富含低环PAHs的孟州一干渠对干流沉积相浓度有较大影响.与水相相比,悬浮、沉积相中PAHs检出种类较多,干流悬浮相∑13PAHs浓度范围为54~155μg/kg,且各环PAHs与悬浮相中TOC含量间存在一定正相关.干流沉积相∑13PAHs浓度范围为31~133μg/kg,其4、5、6环P  相似文献   
995.
酶联免疫吸附分析法测定苯并(a)芘和多氯联苯   总被引:9,自引:0,他引:9  
邓安平 《环境化学》2006,25(3):340-343
对苯并(a)芘作了五种不同的化学修饰,并与载体蛋白交联,制备出十四种单克隆抗体.经单克隆抗体的筛选和实验条件的优化,建立了测定苯并(a)芘的酶联免疫吸附分析法.以4,4'-二氯联苯为测定多氯联苯的酶联免疫吸附分析法的起始物,作了二种化学修饰,制备出九种多克隆抗体,建立了以羊抗多氯联苯抗体为基础的酶联免疫吸附分析法,并用于土壤中多氯联苯的测定.  相似文献   
996.
The rates of photodegradation and photocatalysis of benzo [a]pyrene (BaP) on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃ . The rates of BaP photodegradation at different soil particle size followed the order: less than 1 mm〉less than 0.45 mm〉less than 0.25 mm. When the soil depth increased from 1 mm to 4 ram, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 (0.5%, 1%, 2%, and 3% (wt)) or Fe203 (2%, 5%, 7%, and 10% (wt)) did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.  相似文献   
997.
中国八大湖泊冬季水-气界面CO2通量   总被引:17,自引:0,他引:17  
采用静态箱-气相色谱法对中国不同地区八个湖泊(洞庭湖、鄱阳湖、巢湖、南四湖、洪泽湖、抚仙湖、洱海、滇池)冬季水体的水-气界面CO2通量进行了24h连续观测。结果表明:冬季洞庭湖、巢湖、洱海和滇池24h均为大气CO2的汇,其通量分别为-23.78、-16.08、-24.38、-17.94mg·m-2·h-1;鄱阳湖、南四湖水体则为大气CO2的源,其通量分别为35.76、27.64mg·m-2·h-1;洪泽湖和抚仙湖在晴天时为大气CO2的汇,夜间或阴天为大气CO2的源,但从24h的平均通量来看,洪泽湖为大气CO2的汇,通量为-26.56mg·m-2·h-1;抚仙湖为大气CO2的源,通量16.01mg·m-2·h-1。  相似文献   
998.
在成本-收益分析过程中,生命价值评估为政府确定公共政策收益提供依据。论述生命价值的基本涵义;用劳动市场上的内涵工资法通过分析工资-风险均衡关系来研究生命统计价值,在工人的期望效用曲线与企业的等利润曲线的切点上,企业正常经营,工人实现期望效用最大化。通过对提供曲线求导得到生命价值。生命价值并不针对确定的死亡问题,把生命价值作为死亡赔偿的依据,是对生命价值概念的误解,混淆了生命价值的应用范围。我国法律法规以收入水平为基础确定意外死亡赔偿标准,其实质是人力资本法。  相似文献   
999.
Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g−1 were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g−1 near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g−1 were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g−1 was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.  相似文献   
1000.
Polycyclic aromatic hydrocarbons (PAHs) were analysed in 39 soil samples (0–10 cm upper layer) collected in Belgrade, the capital of Serbia. The sampling sites were randomly selected from urban, urban/recreational and rural areas; the samples were collected in April and December 2003 and July and October 2004. The sum of the 16 PAHs corresponding to the recreational zone (298 μg/kg) was close to the urban zone (375 μg/kg). Mean soil ΣPAH concentration from rural areas was 18 μg/kg dry weight. Comparing to values observed in the urbanized locations around the world, the overall levels of PAHs in this study are low. The PAH ratios obtained pointed to a domination of pyrogenically formed PAHs in the examined soils. The dominant PAHs in soil samples in urban zones were fluoranthene, benz[a]anthracene, phenanthrene and pyrene, mostly emitted from noncatalyst vehicles which are still in use in Serbia. The total carcinogenic potency for each sampling site was calculated. Regardless of the used carcinogenic activity factors, carcinogenic potency of 7 sites were 3–9 times higher than the reference ones indicating the increased carcinogenic burden of soils from these sites.  相似文献   
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