Setting Air Quality Standards for Carcinogens: An Alternative to Mathematical Quantitative Risk Assessment—Discussion Paper

Maynard, Robert; Cameron, K.M.; Fielder, R.J.; McDonald, A.; Wadge, A.

doi:10.1006/rtph.1997.1140

Cited by 11 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Quantitative risk assessment with the linearised multistage model often used for carcinogens has been seriously challenged as unreliable and scientifically unsound,80 and the United Kingdom Committee on Carcinogenicity of Chemicals in Food, Consumer Products, and the Environment, for example, does not support the routine use of quantitative risk assessment for chemical carcinogens. Maynard et al 81 proposed an alternative approach for the purpose of setting air quality standards and recommended a strategy based on the scientific data, decision points and uncertainty factors. Thus, although this review has presented the currently reported risk estimates for leukaemogenesis associated with benzene as the appropriate risk estimates for adverse health effects from low level exposure to benzene, it is possible that these estimates will change as the mechanism for carcinogenesis is further elucidated and more appropriate models, based on mechanistic considerations, emerge.…”

Section: Discussionmentioning

confidence: 99%

Benzene in the environment: an assessment of the potential risks to the health of the population

Duarte‐Davidson¹,

Courage

Rushton³

et al. 2001

Occup Environ Med

251

141

View full text Add to dashboard Cite

Objectives-Benzene has long been recognised as a carcinogen and recent concern has centred on the eVects of continuous exposure to low concentrations of benzene both occupationally and environmentally. This paper presents an overview of the current knowledge about human exposure to benzene in the United Kingdom population based on recently published data, summarises the known human health eVects, and uses this information to provide a risk evaluation for sections of the general United Kingdom population. Method-Given the minor contribution that non-inhalation sources make to the overall daily intake of benzene to humans, only exposure from inhalation has been considered when estimating the daily exposure of the general population to benzene. Exposure of adults, children, and infants to benzene has been estimated for diVerent exposure scenarios with timeactivity patterns and inhalation and absorption rates in conjunction with measured benzene concentrations for a range of relevant microenvironments. Exposures during refuelling and driving, as well as the contribution of active and passive tobacco smoke, have been considered as part of the characterisation of risk of the general population. Results-Infants (<1 years old), the average child (11 years old), and nonoccupationally exposed adults, receive average daily doses in the range of 15-26, 29-50, and 75-522 µg of benzene, respectively, which correspond to average ranges to benzene in air of 3.40-5.76 µg/m 3 , 3.37-5.67 µg/m 3 , and 3.7-41 µg/m 3 for infants, children, and adults, respectively. Infants and children exposed to environmental tobacco smoke have concentrations of exposure to benzene comparable with those of an adult passive smoker. This is a significant source of exposure as a 1995 United Kingdom survey has shown that 47% of children aged 2-15 years live in households where at least one person smokes. The consequence of exposure to benzene in infants is more significant than for children or adults owing to their lower body weight, resulting in a higher daily intake for infants compared with children or non-smoking adults. A worst case scenario for exposure to benzene in the general population is that of an urban smoker who works adjacent to a busy road for 8 hours/day-for example, a maintenance worker-who can receive a mean daily exposure of about 820 µg (equal to an estimated exposure of 41 µg/m 3 ). The major health risk associated with low concentrations of exposure to benzene has been shown to be leukaemia, in particular acute non-lymphocytic leukaemia. The lowest concentration of exposure at which an increased incidence of acute nonlymphocytic leukaemia among occupationally exposed workers has been reliably detected, has been estimated to be in the range of 32-80 mg/m 3 . Although some studies have suggested that eVects may occur at lower concentrations, clear estimates of risk have not been determined, partly because of the inadequacy of exposure data and the few cases. Conclusions-Overall the evidence from human studies suggests that ...

show abstract

Section: Discussionmentioning

confidence: 99%

Benzene in the environment: an assessment of the potential risks to the health of the population

Duarte‐Davidson¹,

Courage

Rushton³

et al. 2001

Occup Environ Med

251

141

View full text Add to dashboard Cite

show abstract

“…Default UFs are, by definition, factors to account for incomplete knowledge. Hence, an additional factor for database deficiency poses a definitional challenge, even before the , Falk-Filipsson et al, 2007;Gaylor et al, 1999;Maynard et al, 1997;Renwick, 1991;Sargent et al, 2013). In the case of developmental toxicity, it can be noted that it is sometimes addressed by applying an additional UF for sensitive subpopulations.…”

Section: Discussionmentioning

confidence: 99%

“…Similarly, severity of effect needs to be defined before applying a UF. Generally, carcinogenicity, mutagenicity, reproductive and/or developmental toxicity are referred to or given as examples of more severe effects (see, e.g., Falk‐Filipsson et al, 2007 ; Gaylor et al, 1999 ; Maynard et al, 1997 ; Renwick, 1991 ; Sargent et al, 2013 ). In the case of developmental toxicity, it can be noted that it is sometimes addressed by applying an additional UF for sensitive subpopulations.…”

Section: Discussionmentioning

confidence: 99%

A scoping review of evaluations of and recommendations for default uncertainty factors in human health risk assessment

Johanson

Moto

Schenk

2022

J of Applied Toxicology

View full text Add to dashboard Cite

Uncertainty factors (UFs) are used to account for uncertainties and variability when setting exposure limits or guidance values. Starting from a proposal of a single UF of 100 to extrapolate from an animal NOAEL to a human acceptable exposure, the aspects of uncertainty and number of UFs have diversified and today there are several risk assessment guidelines that contain schemes of default UFs of varying complexity. In the present work, we scoped the scientific literature on default UFs to map developments regarding recommendations and evaluations of these. We identified 91 publications making recommendations for one or several UFs and 55 publications evaluating UFs without making explicit recommendations about numerical values; these were published between 1954 and 2021. The 2000s was the decade with the largest number of publications, interspecies differences and intraspecies variability being the most frequent topics. The academic sector has been the most active (76 out of 146 publications). Authors from the private sector more often presented UF recommendations, but differences between sectors regarding size of recommendations were not statistically significant. The empirical underpinning of the reviewed recommendations ranges from four to 462 chemicals, that is, relatively low numbers compared with the range of chemicals these default UFs are expected to cover. The recommended UFs have remained remarkably constant, with merely a slight decrease over time. Although chemical specific UFs are preferable, the widespread use of default UFs warrants further attention regarding their empirical and normative basis.

show abstract

“…Risk estimates from varying extrapolation models can differ by five orders of magnitude in the low exposure range for the same data. 15 The magnitude of uncertainty in risk assessment is therefore likely to be greater when using animal data as compared to epidemiologic study results. 16 -18 A further problem of unit riskbased risk assessment is that it quantifies cancer attributable to air pollution by the sum of the risks of each single carcinogen.…”

mentioning

confidence: 99%

Single Pollutant Versus Surrogate Measure Approaches: Do Single Pollutant Risk Assessments Underestimate the Impact of Air Pollution on Lung Cancer Risk?

Röösli

Künzli²,

Schindler³

et al. 2003

Journal of Occupational and Environmental Medicine

View full text Add to dashboard Cite

Cancer risk as a result of air pollution may be quantified by different approaches. We compared the sum of unit risk based effects of single pollutants with an epidemiology-based method by using PM(10) as a surrogate of the total air pollution. The excess rate for lung cancer cases attributable to an increase of 10 microg/m3 in average PM(10) exposure was estimated from available cohort studies. Applying the epidemiology-based risk method to the air pollution situation in the Basel area (Switzerland) resulted in 13.3 (95% CI = 6.9-19.8) excess lung cancer cases per 100,000 person years. This estimate was considerably higher than the unit risk-based estimate yielding 1.1 (range, 0.45-2.8) cancer cases per 100,000 person years. We discuss these discrepancies in light of inherent differences between approaches in toxicology and epidemiology.

show abstract

Setting Air Quality Standards for Carcinogens: An Alternative to Mathematical Quantitative Risk Assessment—Discussion Paper

Cited by 11 publications

References 9 publications

Benzene in the environment: an assessment of the potential risks to the health of the population

Benzene in the environment: an assessment of the potential risks to the health of the population

A scoping review of evaluations of and recommendations for default uncertainty factors in human health risk assessment

Single Pollutant Versus Surrogate Measure Approaches: Do Single Pollutant Risk Assessments Underestimate the Impact of Air Pollution on Lung Cancer Risk?

Contact Info

Product

Resources

About