程潮矿区周边土壤重金属污染风险评价和健康风险评估

采用单因子指数法、内梅罗指数法、潜在生态风险指数法和地累积指数法对程潮铁矿尾矿库及周边农田土壤重金属（镉、砷、铅、铬、铜、镍和锌）的生态风险及人体健康风险进行综合评价。单因子风险评价结果显示,尾矿库土壤As和Cu的污染问题突出,超标率分别为33.3%和41.7%,其它重金属在少数点位超标;农田土壤仅重金属Cd超标。内梅罗综合污染指数结果表明,16.7%的尾矿位点处于中度污染水平,25%的尾矿位点处于重度污染水平;农田土壤整体上较清洁。尾矿土壤中41.7%的Cu处于中等潜在生态风险水平,41.7%的土壤Cu属于中度~强污染地质累积风险,少数位点由于Cd和As含量较高,达到较高等级的潜在生态风险和地质累积风险。农田土壤重金属污染物主要为Cd,局部地区达到中等潜在生态风险和地质累积风险。人体健康风险评价结果表明,As和Cr的非致癌风险和致癌风险均较为突出,整体而言,尾矿区有33.3%的位点存在致癌风险,所有土壤的非致癌风险等级低,对人体健康的风险较低。由于少数位点重金属污染问题突出,仍需加强该尾矿及其周边农田土壤重金属的污染防治和风险管控。     

The genotype of the human cancer cell: implications for risk analysis

An extremely large database describes genotypes associated with the human cancer phenotype and genotypes of human populations with genetic predisposition to cancer. Aspects of this database are examined from the perspective of risk analysis, and the following conclusions and hypotheses are proposed: (1) The genotypes of human cancer cells are characterized by multiple mutated genes. Each type of cancer is characterized by a set of mutated genes, a subset from a total of more than 80 genes, that varies between tissue types and between different tumors from the same tissue. No single cancer-associated gene nor carcinogenic pathway appears suitable as an overall indicator whose induction serves as a quantitative marker for risk analysis. (2) Genetic defects that predispose human populations to cancer are numerous and diverse, and provide a model for associating cancer rates with induced genetic changes. As these syndromes contribute significantly to the overall cancer rate, risk analysis should include an estimation of the effect of putative carcinogens on individuals with genetic predisposition. (3) Gene activation and inactivation events are observed in the cancer genotype at different frequencies, and the potency of carcinogens to induce these events varies significantly. There is a paradox between the observed frequency for induction of single mutational events in test systems and the frequency of multiple events in a single cancer cell, suggesting events are not independent. Quantitative prediction of cancer risk will depend on identifying rate-limiting events in carcinogenesis. Hyperproliferation and hypermutation may be such events. (4) Four sets of data suggest that hypermutation may be an important carcinogenic process. Current mechanisms of risk analysis do not properly evaluate the potency of putative carcinogens to induce the hypermutable state or to increase mutation in hypermutable cells. (5) High-dose exposure to carcinogens in model systems changes patterns of gene expression and may induce protective effects through delay in cell progression and other processes that affect mutagenesis and toxicity. Paradigms in risk analysis that require extrapolation over wide ranges of exposure levels may be flawed mechanistically and may underestimate carcinogenic effects of test agents at environmental levels. Characteristics of the human cancer genotype suggest that approaches to risk analysis must be broadened to consider the multiplicity of carcinogenic pathways and the relative roles of hyperproliferation and hypermutation. Further, estimation of risk to general human populations must consider effects on hypersusceptible individuals. The extrapolation of effects over wide exposure levels is an imprecise process.     

Methods development toward the measurement of polyaromatic hydrocarbon-DNA adducts by mass spectrometry

The measurement of DNA adducts in human samples is at an early stage. The accuracy of some of the current measurements is not defined, the structures are unknown for a significant number of the adducts that have been detected, and there is little information about how many adducts remain to be discovered. This is due largely to the trace amounts of human DNA adducts in any sample. A consequence of this is that the true potential of DNA adducts as indicators of exposure and risk in human toxicology is far from realized. Mass spectrometry, a powerful technique for organic analysis, is the key to exploiting fully the usefulness of human DNA adducts as biomarkers of human exposure and risk. Mass spectrometry can make accurate measurements, discover unknown compounds, and determine the structures of these unknown compounds. However, the trace (very small) amounts of human DNA adducts have limited mass spectrometry's usefulness in analyzing such samples. This project focused on increasing the sensitivity of mass spectrometry for measuring human DNA adducts. Advances in sensitivity have been achieved for two modes of mass spectrometry applied to standards related to DNA adducts: gas chromatography with electron-capture negative ion mass spectrometry, and fast-atom-bombardment mass spectrometry. These advances involve both sample preparation and instrument conditions.     

Environmental chemicals, respiratory hypersensitization and international chemical safety

Allergic hypersensitization to a variety of chemicals, natural and synthetic, is a worldwide health problem. Respiratory tract hypersensitization is responsible for significant morbidity and, in some cases, mortality. An important step in managing and controlling health risks, such as allergic hypersensitization, is to identify the chemical hazard, define dose-effect and dose-response relationships, evaluate exposure, and characterize risk. In practical terms, the risk and safety assessment processes lead to the designation of control limits for exposure to chemicals in air, food, water, and consumer products. The objective of exposure limits is to protect the whole human population, including the most susceptible individuals and 'at risk' groups. The existence of susceptible individuals is a factor that must be taken into account when quantitative chemical risk assessments are being made, and should be covered in the risk characterization. Within a population, individual susceptibility is influenced by genetic and environmental factors and these have regional and national differences. There may be cases where hypersusceptible individuals and groups, such as asthmatic children, are not fully protected by regulatory exposure limits. The International Programme on Chemical Safety, as the global programme on identifying and assessing chemical risks to human health and the environment in order to assist countries in effective management, is striving to elucidate the toxicological basis for chemically-associated disease and advance the basic science and methodology of chemical risk and safety assessment.     

企业并购的人力资源风险研究

企业并购的风险因素很多，其中人力资源风险是决定并购整合是否成功的重要因素，在此背景下首先阐述并购人力资源风险的概念及内涵，接着给出并购人力资源风险成因，然后进行并购人力资源风险类型分析，最后提出并购人力资源风险防范措施。     

Human Error and Reliability of Multistory Reinforced-Concrete Building Construction

This paper develops probabilistic and human reliability models to estimate the probability of structural collapse (system risk) during the construction of typical multistory reinforced-concrete buildings in the presence of human error. Results obtained from the human reliability analysis suggest that errors related to concrete cover and concreting workmanship are more detrimental to system risk than any other errors. Errors related to reinforcement area have a minor effect on system risk, provided that the existing effectiveness of engineering inspections is maintained. The results also show that errors related to installation of steel shores/reshores do not significantly affect the system risk.     

Use of competing conceptions of risk in animal agriculture

This study considers a theory of risk as a means of coping with risk and uncertainty that have become a growing reality for animal agriculture. Microbial contaminations of food, waste management, animal products in the human diet, and transmissible spongiform encephalopathies (TSE) incorporate different conceptions of risk and require different approaches to handling the uncertainty involved. A dichotomous schema is suggested to assist understanding risk that may be adapted to recognizing and handling risk. The polar aspects of the proposal are the probabilistic approach at one end and the contextual understanding at the other. Probabilist conceptions of risk presume that risk is determined by probability and consequence. Contextual conceptions presume that management, law, regulation, media, and public perceptions, as well as the severity of the consequence, will figure prominently in decision making in the face of uncertainty. Relative emphasis on probabilistic characteristics shapes distinct understandings of risk that can be plotted between the poles. We are proposing that these conceptualizations need not be issues only for debate but also for recognition of the probabilistic or contextual nature of the risk. Specific actions and policy may be constructed on the basis of the conceptualization. The bovine spongiform encephalopathy/new variant Creutzfeldt-Jakob disease complex is examined philosophically and methodologically as a contextual challenge to animal agriculture and associated industries. As such, the TSE serve as a case study of effective application of risk theory to risks in animal agriculture.     

Predicting Risk Sensitivity in Humans and Lower Animals: Risk as Variance or Coefficient of Variation.

This article examines the statistical determinants of risk preference. In a meta-analysis of animal risk preference (foraging birds and insects), the coefficient of variation (CV), a measure of risk per unit of return, predicts choices far better than outcome variance, the risk measure of normative models. In a meta-analysis of human risk preference, the superiority of the CV over variance in predicting risk taking is not as strong. Two experiments show that people's risk sensitivity becomes strongly proportional to the CV when they learn about choice alternatives like other animals, by experiential sampling over time. Experience-based choices differ from choices when outcomes and probabilities are numerically described. Zipf's law as an ecological regularity and Weber's law as a psychological regularity may give rise to the CV as a measure of risk. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

煤矿开采环评中土地复垦的措施

土地复垦是煤矿开采中环保对策中的一项技术较强的措施之一,它既有防治水土流失的功能,又有降解有毒污染的功能,并能产生较好的经济效益.但没有科学依据而盲目进行生态恢复,就有可能对环境和人类带来风险,为减少风险,在矿山开发前的环境影响评价中.就应对生态恢复中土地复垦这一措施进行评价,提出合理的恢复模式,为决策部门提供依据.     

Cancer risk assessment of extremely low frequency electric and magnetic fields: a critical review of methodology

This review provides a discussion of cancer risk assessment methodology pertinent to developing a strategy for extremely low frequency electric and magnetic fields (EMF). Approaches taken for chemical agents or ionizing radiation in six key topic areas are briefly reviewed, and then those areas are examined from the perspective of EMF, identifying issues to be addressed in developing a risk assessment strategy. The following recommendations are offered: 1) risk assessment should be viewed as an iterative process that informs an overall judgment as to health risk and consists of a complex of related activities incorporating both positive and negative data, tumor and nontumor end points, and human and nonhuman sources of information; 2) a hazard identification resulting in a conclusion of weak or null effects, such as may be associated with EMF, will need to assign significant weight to animal cancer bioassays conducted under defined exposure conditions as well as to human epidemiologic studies; 3) a default factor to account for possible age differences in sensitivity to carcinogenesis should be included in an EMF risk assessment; 4) lack of evidence of dose response and the apparent lack of DNA reactivity of EMF suggest that a safety (or uncertainty) factor or margin of exposure type of risk characterization may be most appropriate; and 5) an EMF risk assessment should permit at least tentative conclusions to be reached as to the limits of carcinogenic risk from exposure to EMF, and should also define an efficient research agenda aimed at clarifying uncertainties appropriate to a more complete assessment.     

Using new reasoning technology in chemical information systems

Unreliability of numerical data causes difficulties in computer systems for decision-making, risk assessment, and similar activities. Much human judgment is non-numerical and able to make useful evaluations of alternatives under uncertainty. The Logic of Argumentation (LA) offers a basis for computerized support of decision-making in the absence of numerical data, and it is being used in a project on carcinogenic risk assessment, StAR. There are potential applications of LA in other artificial intelligence systems in chemistry, such as for synthesis planning.     

Topics in microbial risk assessment: dynamic flow tree process

Microbial risk assessment is emerging as a new discipline in risk assessment. A systematic approach to microbial risk assessment is presented that employs data analysis for developing parsimonious models and accounts formally for the variability and uncertainty of model inputs using analysis of variance and Monte Carlo simulation. The purpose of the paper is to raise and examine issues in conducting microbial risk assessments. The enteric pathogen Escherichia coli O157:H7 was selected as an example for this study due to its significance to public health. The framework for our work is consistent with the risk assessment components described by the National Research Council in 1983 (hazard identification; exposure assessment; dose-response assessment; and risk characterization). Exposure assessment focuses on hamburgers, cooked a range of temperatures from rare to well done, the latter typical for fast food restaurants. Features of the model include predictive microbiology components that account for random stochastic growth and death of organisms in hamburger. For dose-response modeling, Shigella data from human feeding studies were used as a surrogate for E. coli O157:H7. Risks were calculated using a threshold model and an alternative nonthreshold model. The 95% probability intervals for risk of illness for product cooked to a given internal temperature spanned five orders of magnitude for these models. The existence of even a small threshold has a dramatic impact on the estimated risk.     

Human immunodeficiency virus testing and counseling: nuts and bolts

The human immunodeficiency virus poses an increasing health hazard to women. Physicians must recognize this risk and evaluate their patients for human immunodeficiency virus. Because of general increased awareness and the recommendations that all prenatal patients be offered human immunodeficiency virus testing and counseling, more and more women will be tested, yet counseling has not become a routine aspect in the evaluation of patients. This article reviews the key components of human immunodeficiency virus testing and counseling, including test interpretation, risk assessment, risk reduction, and pretest and posttest counseling. Familiarity with these areas should enable the practitioner to feel comfortable in providing this service.     

Determinants of research follow-up participation in an alcohol treatment outcome trial

We have previously reported a common variation in the liver promoter of the human glucokinase, which is regulated by insulin, in the patients with non-insulin-dependent diabetes mellitus (NIDDM). The variation occurred within a 10-bp region completely conserved between human and rat. Its basic motif was almost identical to the insulin regulatory element of the phosphoenolpyruvate carboxykinase gene. In vitro transfection experiment showed that the G-to-A variation causes a 58% reduction in the promoter activity. After oral glucose challenge, the homozygous A/A subjects had the highest stimulated insulin levels at 60 and 90 minutes and the highest insulin area under the curve as compared to the subjects with other genotypes, which suggested the homozygous A/A subjects were more insulin resistant. As insulin resistance is a risk factor of NIDDM, we concluded that this promoter variation is a risk factor for NIDDM.     

Detection of transmembrane helical segments at the nucleotide level in eukaryotic membrane protein genes

This article presents a review on the association between certain lifestyle characteristics and the risk for lung cancer in humans, using information derived primarily from epidemiological studies. Emphasis will be placed on more recently identified risk factors such as exposure to indoor air pollutants, psychosocial and behavioral influences, diet preferences, and fat intake. More traditional lifestyle factors such as cigarette smoking, occupation, and exposure to outdoor air pollutants will not be reviewed since their association with an increased risk for human lung cancer has been relatively well characterized and extensively reported. Evidence to date suggests that the indoor environment, life's events, and food choices may play a potentially important, albeit varying, role in the etiology of human lung cancer.     

Widespread unilateral increased rib uptake on bone scan

Some neuropathological changes characteristic of aging and Alzheimer's disease (AD) in humans are present also in senescent non-human primates. The human apoE4 allele is associated with an increased risk of developing late-onset familial and sporadic AD. We found that rhesus monkeys and three subspecies of squirrel monkeys are homozygous for apoE phenotype with arginine at positions 112 and 158 as in human apoE4. However, in both species threonine replaces arginine at position 61 of human apoE. It was previously shown that arginine 61 was critical in determining apoE4 lipoprotein distribution in humans.     

Musk xylene: analysis, occurrence, kinetics, and toxicology

1,3-Dimethyl-2,4,6-trinitro-5-tert.-butylbenzene (musk xylene, MX), a synthetic musk, is often used in fragrances and soaps to substitute the natural musk. MX belongs to the common group of nitromusk compounds. The main environmental intake of MX occurs after sewage introduction. The consumption of fish and drinking water as well as the use of body care and perfumed household products could lead to an ingestion of this substance in humans. Although the acute oral and dermal toxicity of MX is low, some hint for the carcinogenic potential of MX was found in one animal experiment. These findings and the high potential of MX as environmental contaminant, it is stable against biological and chemical degradation and it is highly lipophil, raised considerable attention in the field of environmental medicine. Biological monitoring and the toxicology of MX, which previously has been described to occur in human milk, human fat tissue, as well as human blood samples, are of central interest. The aim of this article is to summarize the data on the analysis, occurrence, kinetics, and toxicology of MX. As there is a lack of knowledge on human toxicity and human carcinogenicity of MX, a final evaluation of the toxicological data with regard to public health is still impossible. Nevertheless, in view of the published data about MX, there is no evidence for any substantial human risk at the moment.     

Immunogenetic basis of environmental lung disease: lessons from the berylliosis model

The role of genetic factors has been hypothesized in the pathogenesis of a number of chronic inflammatory lung diseases. The genes of the major histocompatibility complex (MHC) locus on human chromosome 6 have been identified as important determinants in diseases caused both by inorganic and organic compounds such as beryllium, gold, acid anhydrides, isocyanates and grass pollens. Since many environmental factors are the determinants of the immunopathogenesis of asthma, pulmonary granulomatous disorders, hypersensitivity pneumonitis and fibrotic lung disorders, an understanding of the interaction between environmental factors is crucial to epidemiology, prevention and treatment of these disorders. Berylliosis is an environmental chronic inflammatory disorder of the lung caused by inhalation of beryllium dusts. A human leukocyte antigen class II marker (HLA-DP Glu69) has been found to be strongly associated with the disease. In in vitro studies, the gene has been shown to play a direct role in the immunopathogenesis of the disease. In human studies, the gene has been shown to confer increased susceptibility to beryllium in exposed workers, thus suggesting that HLA gene markers may be used as epidemiological probes to identify population groups at higher risk of environmental lung diseases, to identify environmental levels of lung immunotoxicants that would be safe for the entire population and to prevent disease risk associated with occupation, manufactured products and the environment. Studies on the associations between human leukocyte antigens and chronic inflammatory lung disorders are reviewed in the context of the berylliosis model.     

Isolation of islands of Langerhans from human and porcine pancreas for transplantation to humans

The enormous variability of donor factors and organ procurement related variables prevent a constant isolation success, thus reducing the potential number of clinical islet transplants. Since the availability of intact and viable pancreatic donor tissue intended for islet transplantation is limited, the porcine pancreas was selected as a potential source of xenogeneic islets for human recipients. The differences of islet histomorphology between porcine and human pancreas result in a higher intrinsic fragility of porcine islets during collagenase digestion. Nevertheless, if the isolation method is modified to inhibit factors potentially toxic to pig islets, reproducibility of isolation success is higher in the pig as in the human due to a lower variability in donor characteristics and the opportunity of preselection in regard to age and race. If xenograft rejection can be overcome and the risk of xenosis can be minimized, the logistic prerequisites for xenotransplantation of large amounts of viable pig islets into human recipients with insulin dependent diabetes are fulfilled.