Limits...
The use of biomonitoring data in exposure and human health risk assessment: benzene case study.

Arnold SM, Angerer J, Boogaard PJ, Hughes MF, O'Lone RB, Robison SH, Schnatter AR - Crit. Rev. Toxicol. (2013)

Bottom Line: The available data for benzene satisfied most of the Common Criteria and allowed for a risk-based evaluation of the benzene biomonitoring data.Smokers clearly have higher levels of benzene exposure, and biomarker levels of benzene for non-smokers are generally consistent with ambient air monitoring results.While some biomarkers of benzene are specific indicators of exposure, the interpretation of benzene biomonitoring levels in a health-risk context are complicated by issues associated with short half-lives and gaps in knowledge regarding the relationship between the biomarkers and subsequent toxic effects.

View Article: PubMed Central - PubMed

Affiliation: The Dow Chemical Company, Midland, MI 48674, USA. smarnold@dow.com

ABSTRACT
Abstract A framework of "Common Criteria" (i.e. a series of questions) has been developed to inform the use and evaluation of biomonitoring data in the context of human exposure and risk assessment. The data-rich chemical benzene was selected for use in a case study to assess whether refinement of the Common Criteria framework was necessary, and to gain additional perspective on approaches for integrating biomonitoring data into a risk-based context. The available data for benzene satisfied most of the Common Criteria and allowed for a risk-based evaluation of the benzene biomonitoring data. In general, biomarker (blood benzene, urinary benzene and urinary S-phenylmercapturic acid) central tendency (i.e. mean, median and geometric mean) concentrations for non-smokers are at or below the predicted blood or urine concentrations that would correspond to exposure at the US Environmental Protection Agency reference concentration (30 µg/m(3)), but greater than blood or urine concentrations relating to the air concentration at the 1 × 10(-5) excess cancer risk (2.9 µg/m(3)). Smokers clearly have higher levels of benzene exposure, and biomarker levels of benzene for non-smokers are generally consistent with ambient air monitoring results. While some biomarkers of benzene are specific indicators of exposure, the interpretation of benzene biomonitoring levels in a health-risk context are complicated by issues associated with short half-lives and gaps in knowledge regarding the relationship between the biomarkers and subsequent toxic effects.

Show MeSH

Related in: MedlinePlus

(A) Benzene ambient air concentrations in the USA, HEI (2007). Reprinted with permission from the Health Effects Institute, Boston, MA. (B) Benzene ambient air concentrations in European metropolitan areas. Adapted from Bruinen de Bruin et al. (2008) with kind permission from Springer Science + Business Media.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3585443&req=5

f1: (A) Benzene ambient air concentrations in the USA, HEI (2007). Reprinted with permission from the Health Effects Institute, Boston, MA. (B) Benzene ambient air concentrations in European metropolitan areas. Adapted from Bruinen de Bruin et al. (2008) with kind permission from Springer Science + Business Media.

Mentions: For occupational settings, where the primary exposure routes are inhalation and dermal, exposure assessment can be relatively straightforward if the quantity of material used and the work area is relatively well defined. In contrast, assessment of benzene exposure for the general population is harder to quantify because individual lifestyles are extremely variable, ambient weather conditions can impact exposure, and living environments are more diverse. In non-occupational settings, inhalation of benzene is the primary exposure route with minor contribution from dermal and oral sources. Outdoor ambient air concentrations of benzene are dependent on geographical location (i.e. rural versus urban) (Wallace, 1996). Recent surveys in the San Francisco area (Harley et al., 2006), Mexico City and Puebla, Mexico (Tovalin-Ahumada & Whitehead, 2007) and in Florence, Italy (Fondelli et al., 2008) indicate ambient air concentrations of about 0.2–2 µg/m3 (San Francisco), 7 µg/m3 (Puebla), 44 µg/m3 (Mexico City) and 2.3–7 µg/m3 (Florence). US national trends (1994–2009) indicate a 66% decline in the average ambient air benzene concentration (2.7–0.9 µg/m3) for 22 urban monitoring sites (US Environmental Protection Agency (USEPA), 2010). Natural sources of benzene in air include volcanoes and forest fires. Anthropogenic sources of benzene in air include combustible fuel emissions, exhaust from motor vehicles and evaporation of gasoline and solvents, especially in attached garages, industry or hazardous waste sites, and home products (e.g. paint). The range of urban, rural, indoor and personal air benzene concentrations vary from 20- to about 1000-fold in the US and Europe (Figure 1A and B; HEI, 2007 and Bruinen de Bruin, 2008). This wide variability in air benzene concentrations shown in Figure 1(A) (data from Table 4, HEI, 2007) is due to many factors such as sample location (e.g. rural versus urban; outdoor versus indoor), season and time of measurement (e.g. winter; afternoon), number of observations, average sampling time and other factors (e.g. mean versus maximum concentrations). This variability emphasizes the point that public health scientists need to be cognizant of the sources of their data when assessing the potential adverse health effects from exposure to environmental toxicants.Figure 1.


The use of biomonitoring data in exposure and human health risk assessment: benzene case study.

Arnold SM, Angerer J, Boogaard PJ, Hughes MF, O'Lone RB, Robison SH, Schnatter AR - Crit. Rev. Toxicol. (2013)

(A) Benzene ambient air concentrations in the USA, HEI (2007). Reprinted with permission from the Health Effects Institute, Boston, MA. (B) Benzene ambient air concentrations in European metropolitan areas. Adapted from Bruinen de Bruin et al. (2008) with kind permission from Springer Science + Business Media.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3585443&req=5

f1: (A) Benzene ambient air concentrations in the USA, HEI (2007). Reprinted with permission from the Health Effects Institute, Boston, MA. (B) Benzene ambient air concentrations in European metropolitan areas. Adapted from Bruinen de Bruin et al. (2008) with kind permission from Springer Science + Business Media.
Mentions: For occupational settings, where the primary exposure routes are inhalation and dermal, exposure assessment can be relatively straightforward if the quantity of material used and the work area is relatively well defined. In contrast, assessment of benzene exposure for the general population is harder to quantify because individual lifestyles are extremely variable, ambient weather conditions can impact exposure, and living environments are more diverse. In non-occupational settings, inhalation of benzene is the primary exposure route with minor contribution from dermal and oral sources. Outdoor ambient air concentrations of benzene are dependent on geographical location (i.e. rural versus urban) (Wallace, 1996). Recent surveys in the San Francisco area (Harley et al., 2006), Mexico City and Puebla, Mexico (Tovalin-Ahumada & Whitehead, 2007) and in Florence, Italy (Fondelli et al., 2008) indicate ambient air concentrations of about 0.2–2 µg/m3 (San Francisco), 7 µg/m3 (Puebla), 44 µg/m3 (Mexico City) and 2.3–7 µg/m3 (Florence). US national trends (1994–2009) indicate a 66% decline in the average ambient air benzene concentration (2.7–0.9 µg/m3) for 22 urban monitoring sites (US Environmental Protection Agency (USEPA), 2010). Natural sources of benzene in air include volcanoes and forest fires. Anthropogenic sources of benzene in air include combustible fuel emissions, exhaust from motor vehicles and evaporation of gasoline and solvents, especially in attached garages, industry or hazardous waste sites, and home products (e.g. paint). The range of urban, rural, indoor and personal air benzene concentrations vary from 20- to about 1000-fold in the US and Europe (Figure 1A and B; HEI, 2007 and Bruinen de Bruin, 2008). This wide variability in air benzene concentrations shown in Figure 1(A) (data from Table 4, HEI, 2007) is due to many factors such as sample location (e.g. rural versus urban; outdoor versus indoor), season and time of measurement (e.g. winter; afternoon), number of observations, average sampling time and other factors (e.g. mean versus maximum concentrations). This variability emphasizes the point that public health scientists need to be cognizant of the sources of their data when assessing the potential adverse health effects from exposure to environmental toxicants.Figure 1.

Bottom Line: The available data for benzene satisfied most of the Common Criteria and allowed for a risk-based evaluation of the benzene biomonitoring data.Smokers clearly have higher levels of benzene exposure, and biomarker levels of benzene for non-smokers are generally consistent with ambient air monitoring results.While some biomarkers of benzene are specific indicators of exposure, the interpretation of benzene biomonitoring levels in a health-risk context are complicated by issues associated with short half-lives and gaps in knowledge regarding the relationship between the biomarkers and subsequent toxic effects.

View Article: PubMed Central - PubMed

Affiliation: The Dow Chemical Company, Midland, MI 48674, USA. smarnold@dow.com

ABSTRACT
Abstract A framework of "Common Criteria" (i.e. a series of questions) has been developed to inform the use and evaluation of biomonitoring data in the context of human exposure and risk assessment. The data-rich chemical benzene was selected for use in a case study to assess whether refinement of the Common Criteria framework was necessary, and to gain additional perspective on approaches for integrating biomonitoring data into a risk-based context. The available data for benzene satisfied most of the Common Criteria and allowed for a risk-based evaluation of the benzene biomonitoring data. In general, biomarker (blood benzene, urinary benzene and urinary S-phenylmercapturic acid) central tendency (i.e. mean, median and geometric mean) concentrations for non-smokers are at or below the predicted blood or urine concentrations that would correspond to exposure at the US Environmental Protection Agency reference concentration (30 µg/m(3)), but greater than blood or urine concentrations relating to the air concentration at the 1 × 10(-5) excess cancer risk (2.9 µg/m(3)). Smokers clearly have higher levels of benzene exposure, and biomarker levels of benzene for non-smokers are generally consistent with ambient air monitoring results. While some biomarkers of benzene are specific indicators of exposure, the interpretation of benzene biomonitoring levels in a health-risk context are complicated by issues associated with short half-lives and gaps in knowledge regarding the relationship between the biomarkers and subsequent toxic effects.

Show MeSH
Related in: MedlinePlus