摘要:

SUMMARY AND CONCLUSIONSIn summary, risk analysis is not yet well practiced in developing countries, although there are numerous, diverse environmental and other risk‐related issues and concerns that need attention. A few initiatives have been taken, but, so far, they have created only relatively small impact in a few areas. Many risk issues may not be addressed, partly as a result of lack of resources and inadequate knowledge by policy makers.Risk analysis is an essential tool for the planning and implementation of development projects. To enhance its use, however, risk analysis approaches and methods must be adapted to developing countries, and this requires research. Unfortunately, funds for research, in general, are hard to find. There are other problems in the implementation of risk analysis. Trained professionals on risk analysis are few. Existing institutions that are tasked with resolving environmental and other risk issues are overburdened. Risk‐related data are sorely lacking. Resources are very limited for addressing numerous natural and technological hazards.In most developing countries, political and economic stability is still threatened by both internal and external forces, hence, that is what receives priority attention. Activities like risk analysis, which generally lead to long‐term results and benefits, do not get enough interest. In addition, there is still little public awareness of risks even among those who have passed the stage of survival; thus, there is little public concern about them.We cannot afford this lack of concern for long. In the Philippines, the government was the first to recognize after our peaceful revolution in 1986 that “the environmental issues can add fuel to the insurgency; they can also hamper efforts towards national recovery”.(4)To this point, I have added that risk management (including risk assessment and risk communication), like attainment of peace and freedom, is a social imperative because risk issues affect our health, safety, and both our physical and economic well‐being.(7)Many of such issues in developing countries have not only local, but also global origin and impacts. They thus deserve the interest of

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01187.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01188.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

One‐hit formulas are widely believed to be “conservative” when used to analyze carcinogenesis bioassays, in the sense that they will rarely underestimate risks of cancer at low exposures. Such formulas are generally applied to the lifetime incidence of cancer at a specific site, with risks estimated from animal data at zero dose (control), and two or more additional doses that are appreciable fractions of a maximum tolerated dose. No empirical study has demonstrated that the one‐hit formula is conservative in the sense described. The Carcinogenesis Bioassay Database System contains data on 1212 separate bioassays of 308 chemical substances tested at exactly three evaluable doses. These provided sufficient data to examine 8432 specific combinations of cancer site with sex, species, and chemical. For each of these we fitted a one‐hit formula to the zero and maximum dose data points, then examined the relation of the fitted curve to the incidence rate observed at the mid‐dose, with and without adjustment for intercurrent mortality.Both underestimates and overestimates of risk at mid‐dose occurred substantially more often than expected by chance. We cannot tell whether such underestimates would occur at lower doses, but offer six biological reasons why underestimates might be expected. In a high percentage of animal bioassays, the one‐hit formula is not conservative when applied in the usual way to animal data. It remains possible that the one‐hit formula may indeed be conservative at sufficiently low doses (below the observational range), but the usual procedure, applied to the usual dose range, can be nonconservative in estimating the slope of the formula at such low doses. Risk assessments for regulation of carcinogens should incorporate some measure of addit

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01189.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

This paper critiques the Environmental Protection Agency's assessment of risk for hazardous waste incineration at sea. It reviews operational and transportation risks and considers alternative approaches for managing chlorinated organic hazardous wastes. It concludes that depending on the scale of the program, ocean incineration will either contribute little to the overall management of this waste stream or else it will engender significant risks, especially in the coastal environment. Furthermore, past assessments on the part of EPA have tended to understate the risks of incineration at sea while simultaneously holding out the promise of the technology as a commercial‐scale management option. Finally, this paper observes that the Western European countries that pioneered incineration in the North Sea are now finding practical alternatives. It is recommended that waste reuse, on‐site treatment, and techniques of waste reduction provide viable alternatives and obviate the need for incineration at

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01190.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Physiologically based pharmacokinetic (PBPK) models describing the uptake, metabolism, and excretion of xenobiotic compounds are now proposed for use in regulatory health‐risk assessments. In this study we investigate the extent of PCE metabolism arising from domestic respiratory exposure to tetrachloroethylene (PCE) from ground water, as predicted using a PBPK model. Indoor exposure patterns we use as input to the PBPK model are realistic ones generated from a three‐compartment model describing volatilization of PCE from domestic water into household air. Values we use for the metabolic parameters of the PBPK model are estimated from data on urinary metabolites in workers exposed to PCE. It is shown that for respiratory PCE exposure due to typical levels of PCE in ground water, use of time‐weighted average air concentrations with a steady‐state PBPK model yields estimates of total metabolized PCE similar to those obtained using completely dynamic modeling, despite considerable uncertainty in key exposure‐ and metabolic‐model parameters. These findings suggest that, for PCE, risk estimation taking pharmacokinetics into account may be accomplished using a simple analyt

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01191.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Previous applications of carcinogenic risk assessment using mathematical models of carcinogenesis have focused largely on the case where the level of exposure remains constant over time. In many situations, however, the dose of the carcinogen varies with time. In this paper, we discuss both the classical Armitage–Doll multistage model and the Moolgavkar–Venzon–Knudson two–stage birth–death–mutation model with time‐dependent dosing regimens. Bounds on the degree of underestimation of risk that can occur through the use of a simple time‐weighted average dose are derived by means of comparison with an equivalent constant dose corresponding to the actual risk under the time‐depende

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01192.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Twenty‐three chemicals were selected for comparison of the carcinogenic potencies estimated from epidemiological data to those estimated from animal carcinogenesis bioassays. The chemicals were all those for which reasonably strong evidence of carcinogenicity could be found in humans or animals and for which suitable data could be obtained for quantifying carcinogenic potencies in both humans and animals. Many alternative methods of analyzing the bioassay data were investigated. Almost all of the methods yielded potency estimates that were highly correlated with potencies estimated from epidemiological data; correlations were highly statistically significant (p<0.001), with the corresponding correlation coefficients ranging as high as 0.9. These findings provide support for the general use of animal data to evaluate carcinogenic potential in humans and also for the use of animal data to quantify human ris

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01193.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01194.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01195.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0272-4332    

DOI:10.1111/j.1539-6924.1988.tb01196.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY