Elizabeth L. Anderson

Risk assessment and indoor air quality

Introduction to Risk Assessment The Elements of Human Health Risk Assessment Hazard Identification of Indoor Air Pollutants Dose-Response Assessment Exposure Characterization Risk Characterization Characterization of Uncertainty Measurement of Indoor Air Contaminants Application of Risk Assessment Future Directions in Risk Assessment

Estimation of unit risk for coke oven emissions

In 1984, based on epidemiological data on cohorts of coke oven workers, USEPA estimated a unit risk for lung cancer associated with continuous exposure from birth to 1 μg/m3 of coke oven emissions, of 6.2 × 10−4. This risk assessment was based on information on the cohorts available through 1966. Follow-up of these cohorts has now been extended to 1982 and, moreover, individual job histories, which were not available in 1984, have been constructed. In this study, lung cancer mortality in these cohorts of coke oven workers with extended follow-up was analyzed using standard techniques of survival analysis and a new approach based on the two stage clonal expansion model of carcinogenesis. The latter approach allows the explicit consideration of detailed patterns of exposure of each individual in the cohort. The analyses used the extended follow-up data through 1982 and the detailed job histories now available. Based on these analyses, the best estimate of unit risk is 1.5 × 10−4 with 95% confidence interval = 1.2 × 10−4−1.8 × 10−4.

Mechanisms of Asbestos Carcinogenicity

We present a brief review of different potential mechanisms at the molecular and cellular levels that may be involved in asbestos-induced carcinogenicity. The usefulness of considering such mechanisms in developing appropriate biologically based models to estimate carcinogenic risk at environmental levels of asbestos fibers is discussed.

An Exploratory Study of Variations in Exposure to Environmental Tobacco Smoke in the United States

There is considerable interest in assessing exposure to environmental tobacco smoke (ETS) and in understanding the factors that affect exposure at various venues. The impact of these complex factors can be researched only if monitoring studies are carefully designed. Prior work by Jenkins et al. gathered personal monitor and diary data from 1,564 nonsmokers in 16 metropolitan areas of the United States and compared workplace exposures to ETS with exposures away from work. In this study, these data were probed further to examine (1) the correspondence between work and away-from-work exposure concentrations of ETS; (2) the variability in exposure concentration levels across cities; and (3) the association of ETS exposure concentrations with select socioeconomic, occupation, and lifestyle variables. The results indicate (1) at the population level, there was a positive association between ETS concentrations at the work and away-from-work environments; (2) exposure concentration levels across the 16 cities under consideration were highly variable; and (3) exposure concentration levels were significantly associated with occupation, education, household income, age, and dietary factors. Workplace smoking restrictions were associated with low ETS concentration levels at work as well as away from work. Generally, the same cities that exhibited either lower or higher away-from-work exposure concentration levels also showed lower or higher work exposure concentration levels. The observations suggest that similar avoidance characteristics as well as socioeconomic and other lifestyle factors that affect exposure to ETS may have been in operation in both away-from-work and work settings.

A Framework and Case Study for Exposure Assessment in the Voluntary Children's Chemical Evaluation Program

A conceptual framework is presented for conducting exposure assessments under the U.S. EPAs Voluntary Childrens Chemical Evaluation Program (VCCEP). The VCCEP is a voluntary program whereby companies that manufacture chemicals of potential concern are asked to conduct hazard, exposure, and risk assessments for the chemicals. The VCCEP is unique in its risk-based, tiered approach, and because it focuses on children and requires a comprehensive consideration of all reasonably foreseeable exposure pathways for a particular chemical. The consideration of all potential exposure pathways for some commonly used chemicals presents a daunting challenge for the exposure assessor. This article presents a framework for managing this complicated process, and illustrates the application of the framework with a hypothetical case study. The framework provides guidance for interpreting multiple sources of exposure information and developing a plausible list of exposure pathways for a chemical. Furthermore, the framework provides a means to process all the available information to eliminate pathways of negligible concern from consideration. Finally, the framework provides guidance for utilizing the tiered approach of VCCEP to efficiently conduct an assessment by first using simple, screening-level approaches and then, if necessary, using more complex, refined exposure assessment methods. The case study provides an illustration of the major concepts.

New Risk Assessment Initiatives in Epa

This paper describes EPAs recent efforts to ensure consistency and technical competence of the agencys risk assessments. These include five risk assessment guidelines proposed in November 1984 and January 1985 and establishment of a Risk Assessment Forum. The technical provisions of the five guidelines have been outlined.

General Introduction To Risk Assessment and Risk Management

The process of risk assessment and risk management is widely recognized in the United States for making policy decisions to control the risk associated with toxic chemical exposures. This two-step process, to first evaluate risk and then to decide what if anything should be done to reduce exposures, was first adopted by the U.S. Environmental Protection Agency (USEPA) in 1976 in its announcement of guidelines for assessing cancer risk (USEPA, 1976; Albert et al., 1977). This approach was later endorsed by committees of the National Academy of Sciences (NAS) as the most appropriate process for informed public policy decisions to protect public health from toxic chemical exposures (NAS, 1982, 1983). Other U.S. federal interagency committees reviewed the basis for cancer risk assessment and published background documents that are largely consistent with the earlier and much briefer statement of risk assessment guidance published by the USEPA in 1976 (IRLG, 1979; OSTP, 1984). The USEPA has recently published updates of its cancer risk assessment guidelines and guidelines for other health effects which take into account its experience in assessing cancer risks for hundreds of chemicals