Comparative Potency Method for Cancer Risk Assessment: Application to Diesel Particulate Emissions1

An estimation of the human lung cancer “unit risk” from diesel engine particulate emissions has been made using a comparative potency approach. This approach involves evaluating the tumorigenic and mutagenic potencies of the particulates from four diesel and one gasoline engine in relation to other combustion and pyrolysis products (coke oven, roofing tar, and cigarette smoke) that cause lung cancer in humans. The unit cancer risk is predicated on the linear nonthreshold extrapolation model and is the individual lifetime excess lung cancer risk from continuous exposure to 1 μg carcinogen per m³ inhaled air. The human lung cancer unit risks obtained from the epidemiologic data for coke oven workers, roofing tar applicators, and cigarette smokers were, respectively, 9.3 × 10^?4, 3.6 × 10^?4, and 2.2 × 10^?6 per μg particulate organics per m³ air. The comparative potencies of these three materials and the diesel and gasoline engine exhaust particulates (as organic extracts) were evaluated by in vivo tumorigenicity bioassays involving skin initiation and skin carcinogenicity in SENCAR mice and by the in vitro bioassays that proved suitable for this analysis: Ames Salmonella microsome bioassay, L5178Y mouse lymphoma cell mutagenesis bioassay, and sister chromatid exchange bioassay in Chinese hamster ovary cells. The relative potencies of the coke oven, roofing tar, and cigarette smoke emissions, as determined by the mouse skin initiation assay, were within a factor of 2 of those determined using the epidemiologic data. The relative potencies, from the in vitro bioassays as compared to the human data, were similar for coke oven and roofing tar, but for the cigarette smoke condensate the in vitro tests predicted a higher relative potency. The mouse skin initiation bioassay was used to determine the unit lung cancer risk for the most potent of the diesel emissions. Based on comparisons with coke oven, roofing tar, and cigarette smoke, the unit cancer risk averaged 4.4 × 10^?4. The unit lung cancer risks for the other, less potent motor-vehicle emissions were determined from their comparative potencies relative to the most potent diesel using three in vitro bioassays. There was a high correlation between the in vitro and in vivo bioassays in their responses to the engine exhaust particulate extracts. The unit lung cancer risk per μg particulates per m³ for the automotive diesel and gasoline exhaust particulates ranged from 0.20 × 10^?4 to 0.60 × 10^?4; that for the heavy-duty diesel engine was 0.02 × 10^?4. These unit risks provide the basis for a future assessment of human lung cancer risks when combined with human population exposure to automotive emissions.     

Integrating research,policy, and practice in juvenile justice education

This article provides an overview of the history and context leading to Florida's efforts to implement an evaluation-driven research and associated quality assurance system for its juvenile justice education policies and practices. The Juvenile Justice Educational Enhancement Program began implementing Florida's evaluation research and quality assurance system to juvenile justice education in 1998. The article includes a brief summary of articles comprising this special issue of Evaluation Review that address the Juvenile Justice Educational Enhancement Program's various functions, methodological components, data, preliminary findings, continuing evaluation research efforts, and impediments.     

"Languaging" factors affecting clients' acceptance of forgiveness intervention in marital therapy

Forgiveness is a significant intervention for healing interpersonal injury. Yet therapists do not often use forgiveness intervention. Employing a semantic perspective and a survey design (n = 307), this study investigated whether the language used to rationalize forgiveness intervention (set at five levels: personal growth, relationship reconciliation, spiritual issue, others' growth, and pardoning/condoning) may affect its acceptability. Gender, problem type, and choice were also included in the analyses. Overall, forgiveness was found to be an acceptable intervention. A pardoning/condoning rationale led to significantly lower acceptability ratings. Other results are discussed. We conclude that therapists should be less apprehensive about using forgiveness, but need to inform themselves better concerning its purpose, process, and articulation.     

Why mentoring in the workplace works

Workplaces are ideal contexts for mentoring relationships between adults and older youth. To teach the competencies required in contemporary workplaces (many of which are equally useful in other settings), mentors need to use sophisticated teaching behaviors, which the authors characterize as reflective questioning and problem solving.     

The impact of touch-tone data entry on reports of HIV and STD risk behaviors in telephone interviews

Respondents concerns about privacy can decrease reporting of HIV and STD risk behaviors in general population telephone surveys. The purpose of this paper is to describe the results of an experimental study evaluating whether one method for increasing privacy, touch-tone data entry (TTDE), is effective in increasing estimates of sexual behaviors from a population-based survey. We conducted a random-digit-dial telephone survey of adults in New Jersey (n = 405), with half the respondents using TTDE for answering sexual behavior questions. TTDE led to increased reports of same-sex sexual behavior, certain HIV and STD risk factors, and concern about one s risk for HIV and STD transmission. TTDE also narrowed the difference between men s and women s reports of the number of different sexual partners over the past 10 years. The feasibility and limitations of TTDE are discussed, as well as possible alternative interpretations that consider the impact of TTDE on the dynamics of the interaction between the respondent and the interviewer.     

Multi-family psychoeducation groups in the treatment of children with mood disorders

This study examined the impact of adjunctive multi-family psychoeducation groups (MFPG) on mood-disordered children aged 8 to 11 and their families. Participants were 35 children and 47 parents from families randomly assigned to either immediate MFPG plus treatment as usual (n = 18) or a 6-month wait-list condition plus treatment as usual (n = 17). At the 6 month follow up, immediate treatment families reported: Increased parental knowledge about childhood mood symptoms; increased positive family interactions as reported by the parent; increased perceptions of parental support as reported by children; and increased utilization of appropriate services by families. Expected impact on decreasing negative family interactions was not found. Results are largely consistent with hypothesized findings and support the need to further investigate the adjunctive role of psychoeducation in the treatment of childhood mood disorders.