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.     

Health in household context: living arrangements and health in late middle age

People living in some arrangements show better health than persons in other living arrangements. Recent prospective studies document higher mortality among persons living in particular types of households. We extend this research by examining the influence of household structure on health using longitudinal data. We theorize that individuals experience role-based household relations as sets of resources and demands. In certain household structures, individuals are more likely to perceive that the demands made on them outweigh the resources available to them. This perceived imbalance poses a risk to individual health. We test our expectations by analyzing the relationship between living arrangements and health using data from waves 1 and 2 of the Health and Retirement Study. We focus on persons ages 51-61 and explore gender differences. We find prospective links between household structure and self-rated health, mobility limitation, and depressive symptoms. Married couples living alone or with children only are the most advantaged; single women living with children appear disadvantaged on all health outcomes. Men and women in other household types are disadvantaged on some health outcomes. Our results suggest that the social context formed by the household may be important to the social etiology of health. In addition, they qualify the well-known link between marital status and health: The effect of marital status on health depends on household context.     

Overcoming hopelessness and social isolation: the ENGAGE model for working with neglecting families toward permanence

The Adoption and Safe Families Act of 1997 (ASFA) mandates policies designed to increase the frequency and speed with which permanency is achieved for children in the child welfare system. ASFA's focus is on child safety, permanency, and well-being. The expectation that parents correct neglectful conditions within specified time frames places an increased ethical responsibility on child welfare staff. Carrying out this responsibility requires vigorous and innovative approaches to engaging and working with neglectful families. Drawing on a well-established conceptual framework for understanding the determinants of effective parenting, the authors derive the ENGAGE (Engagement, Needs assessment, Goal setting, Assessment of progress, Goal achievement, Ending work) model for achieving permanency within the policy structure. The model incorporates creative client engagement, assessment of family needs, mutual goal setting, the goal achievement process, termination, and aftercare.     

Evaluating consumer satisfaction in residential continuing care settings

The outcome of the project reported on here is a client-centered consumer satisfaction questionnaire designed to evaluate new models of residential continuing care in Alberta, Canada. Satisfaction is defined as a multi-dimensional construct that is grounded in the consumer's experience. Consultation with the clients of the services during development of the instrument ensured that characteristics important to the clients were assessed. The result is an instrument with which to measure satisfaction that is fully client-centered and that, with appropriate modifications, can be used to monitor any client-centered program for cognitively-able continuing care clients.     

Positive youth development: thriving as the basis of personhood and civil society

Positive youth development is conceptualized within a developmental systems theoretical model. The role of thriving processes and civic engagement in positive youth development is discussed.     

It's a rave new world: estimating the prevalence and perceived harm of ecstasy and other drug use among club rave attendees

The use of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") appears to be increasing worldwide, with "rave" attendees being one high-risk population. To date, however, only one study has collected ecstasy use information from rave attendees in the United States. To address this limitation, we collected self-report drug use information from 70 adult "club rave" attendees within the Baltimore-Washington corridor in April and May 2002. Data collection was scheduled between 12 A.M. and 5 A.M. Participation rates were high, with 85 percent of the club rave attendees completing the interview. Eighty-six percent of the respondents reported lifetime ecstasy use, 51 percent reported 30-day use, and 30 percent reported using ecstasy within the two days preceding the interview. While past-year ecstasy users were comparable to non-users with respect to a host of demographic and drug use variables, non-ecstasy users were significantly more likely than past-year users to perceive risks associated with the regular use of alcohol and ecstasy. Not surprisingly, non-ecstasy users were significantly more likely than past-year users to perceive harmful long-term physical and psychological effects associated with ecstasy ingestion. These findings suggest that rave attendees may be an important population for ecstasy-related prevention efforts.     

Treatment of incarcerated, sexually-abused adolescent females: an outcome study

This study examined the psychosocial functioning of 100 adolescent females (ages 12-17) sentenced to secure care in a southeastern state and the impact of gender-specific, cognitive-behavioral therapy (CBT) intervention on the psychosocial functioning of subjects who reported a history of sexual abuse. The Multidimensional Adolescent Assessment Scale (MAAS) was used to assess psychosocial functioning. Pre-test scores on the MAAS revealed significantly higher scores on 12 of 16 dimensions of psychosocial functioning and higher rates of serious criminal behavior for youth who subsequently disclosed sexual abuse histories as compared to those without such histories. At post-test, statistically significant improvements in psychosocial functioning were observed on 14 of 16 MAAS subscales for those who received the CBT intervention. Thus, incarcerated female adolescents who reported a history of sexual abuse demonstrated more impairment in their functioning as compared to those without a reported history of sexual abuse and responded positively to gender-specific, CBT-based intervention.     

Examining links between cocaine use and street‐based sex work in New South Wales,Australia

We examined potential links between cocaine use and street‐based sex work in New South Wales, Australia, following reports of increased cocaine use among injection drug users (IDU). Police data on prostitution and possession/use of cocaine was analysed using time series analysis. Interviews with key informants and IDU were also conducted, and data on cocaine use from ongoing monitoring systems targeted at IDU were analyzed. There was a clear increase in cocaine use among IDU which occurred in 2001. This occurred at the same time as an increase in prostitution offenses. Qualitative data suggested a greater number of primary heroin users were engaging in street‐based sex work, which was driven in part by the increases in cocaine use among this group. Subsequent reductions in cocaine availability led to decreased cocaine use and possession offenses, along with reductions in prostitution offenses.     

A Goodness-of-Fit Test for Location-Scale Max-Stable Distributions

In this article, a technique based on the sample correlation coefficient to construct goodness-of-fit tests for max-stable distributions with unknown location and scale parameters and finite second moment is proposed. Specific details to test for the Gumbel distribution are given, including critical values for small sample sizes as well as approximate critical values for larger sample sizes by using normal quantiles. A comparison by Monte Carlo simulation shows that the proposed test for the Gumbel hypothesis is substantially more powerful than some other known tests against some alternative distributions with positive skewness coefficient.