ISSN:1080-7039    

DOI:10.1080/10807039509379979

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1080-7039    

DOI:10.1080/10807039509379980

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1080-7039    

DOI:10.1080/10807039509379981

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1080-7039    

DOI:10.1080/10807039509379982

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The process of quantitatively predicting the likelihood of an adverse response in humans or wildlife due to exposure to one or more chemicals is collectively known as environmental risk assessment. Quantitative risk assessment has been practiced in the United States and Canada for nearly 20 years and is the basis for most environmental and many occupational health regulations in North America. However, only since 1990 has it begun to receive serious consideration in Europe, Australia, Asia, and other regions. This paper reviews the historical evolution of health risk assessment in the United States and the scientific shortcomings in the process that have been introduced due to various regulatory policies. Despite these limitations and the reluctance of some countries to implement risk‐based policies, risk assessment will undoubtedly grow in importance within the international arena as other countries search for an ideal balance between cost and risk reduction. With the emergence of risk analysis as an international tool for understanding environmental issues, several improvements to the risk assessment process are recommended here that the United States and other countries could immediately incorporate into hazard identification, dose‐response and exposure assessments, and risk characterization. Examples of these improvements include use of a weight‐of‐evidence approach, physiologically‐based pharmacokinetic (PB‐PK) modelling, Monte Carlo techniques, and uncertainty analyses. These recommendations could, if coupled with an understanding of the historical experience in the United States, lead to superior environmental risk assessment policies for all countries as they enter the 21st century.

ISSN:1080-7039    

DOI:10.1080/10807039509379983

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A technique is proposed for calculating a population risk from exposure to a toxicant, based on human data grouped by exposure levels. Of concern is a health effect that is measured on a continuous (nonquantal) scale. In the absence of response levels considered to be adverse, a range of normal, or abnormal, values can be established for the current population. For any change in the exposure levels, the change in the probability of abnormal values of a health effect can be calculated for each of the subgroups and summed to obtain the risk for the population. This requires establishing a relationship between the health effect and exposure, and a measure of the distribution of effects within subgroups. In the case of normally distributed effects, the only additional information needed is an estimate of the standard deviation for each of the subgroups. Then, changes in probabilities of abnormal values can be estimated from changes in exposures, to aid in risk/benefit decisions for product development or regulation. The procedure is illustrated with data presented by Gladen et al. (1988) on the reduction of the Bayley Psychomotor Development Index for 12‐month old infants exposed to polychlorinated biphenyls (PCBs) transplacentally. The additional probability of abnormally low index scores is calculated for infants potentially exposedin uteroto the release of PCBs from silicone in some types of medical devices. If such exposure occurs, this neurotoxic risk is estimated to be quite low.

ISSN:1080-7039    

DOI:10.1080/10807039509379984

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Ordinary algebra may be used to backcalculate health‐based cleanup targets in deterministic risk assessments, but it does not work in interval or probabilistic risk assessments. Equations with interval or random variables do not follow the rules of ordinary algebra. This paper explains the need for more sophisticated methods to backcalculate soil cleanup targets when using interval or random variables.

ISSN:1080-7039    

DOI:10.1080/10807039509379985

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

When evaluating a fully probabilistic risk assessment, say at a hazardous waste site, the risk manager needs a risk management policy that distinguishes an acceptable distribution of risk from an unacceptable one. This manuscript explores several alternative ways to define the acceptability of a distribution of risk. This manuscript also presents methods to backcalculate distributions for cleanup targets under the alternative risk management policies if the need arises.

ISSN:1080-7039    

DOI:10.1080/10807039509379986

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1080-7039    

DOI:10.1080/10807039509379987

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1080-7039    

DOI:10.1080/10807039509379977

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor