Comparison of the Cancer Risk of Methylene Chloride Predicted from Animal Bioassay Data with the Epidemiologic Evidence

Methylene chloride has been shown to be a lung and liver carcinogen in the mouse; yet, the current epidemiologic data show no adverse health effects associated with chronic exposure to this compound. Hearne et al. have compared the results of a large mortality study on occupational exposure to methylene chloride to the human risk predictions based on the rodent bioassay to point out the inconsistency between the animal toxicologic and human epidemiologic data. The maximum number of lung and liver cancers predicted due to methylene chloride exposure based on the rodent bioassay data was 24 compared to 14 deaths from these cancers actually observed in the Hearne et al. epidemiology study. We assess the minimum risk detectable by the human study in order to calculate the upperbound potency of methylene chloride and compare it to the potency derived from the bioassay data. Results from the epidemiology study imply an upperbound potency of 1.5 x 10(-2) per ppm, compared to 1.4 x 10(-2) per ppm calculated using the most conservative analysis of the animal data. We conclude that the negative epidemiology study of Hearne et al. is not sufficiently powerful to show that the risk is inconsistent with the human risk estimated by modeling the rodent bioassay data. Specifically, the doses to which the workers were exposed, the population studied, and the latency period were not adequate to determine that the risks are outside the bounds of the risk estimates predicted by low-dose modeling of the animal data.     

MULTISTAGE SAMPLING FOR RAW WOOL CHARACTERISTICS

The problem of evaluating the sampling variance of a mean when units are subsampled from a multistage sample is discussed. In particular, a specific problem arising in the sampling of wool where information on the identity of subsampled units is not available is dealt with by introducing a simple model to account for the variability in the unobserved numbers of observations within the multistage categories. Estimation aspects of the wool example are also dealt with.     

Do videotapes improve knowledge and attitudes about AIDS?

Three popular videotapes were assessed for their effectiveness in improving knowledge and attitudes about acquired immune deficiency syndrome (AIDS). One hundred forty-four university students completed knowledge and attitude questionnaires and then watched either an AIDS or a control tape. Half the students completed posttest questionnaires immediately after seeing the tape, and half were tested 1 month later. Students who viewed an AIDS tape showed increased knowledge at immediate and 1-month posttesting (p less than .01); the amount of increase declined over the month, however (p = .012). Students who saw two of the AIDS tapes showed an increase in compassion toward people with AIDS when tested immediately after the tape (p less than .01); but 1 month later, only those students who had viewed a third AIDS tape showed an increase in compassion (p less than .01). The AIDS tapes failed to bring about improvements in attitudes toward preventive behavior. The authors concluded that tapes about AIDS can lead to modest changes in knowledge and perhaps in attitudes; more significant changes, however, probably depend on multimedia interventions that include guided discussions as well as audiovisual and other components.     

Monitoring adolescent gambling in Minnesota

Youth gambling was investigated in a prospective sample of 532 Minnesota adolescents and young adults. Of particular interest was the possible impact among the study sample of a recent state lottery and of reaching the legal age for gambling on changes in the rate and type of gambling. Overall rates of gambling involvement and pathological gambling did not change across the 1.5 year interval. However, a preference for certain types of gambling activities (e.g., lottery, casino machines) significantly increased, whereas more informal and unregulated games (e.g., betting on games of personal skill) significantly decreased. Also, access to gambling activities by underage youths was high, suggesting the need for tighter controls of legalized games and greater awareness of this problem by the gaming industry and public health officials.Support for this study was provided by the Minnesota Department of Human Services, Compulsive Gambling Treatment Program. A version of this work was presented at the Seventh National Conference on Gambling Behavior, July 24, 1994, New London, CT.     

Stories of Wreck Bay

This is the first plenary address by an Aboriginal woman at an Australian Family Therapy Conference. The author reminisces about her early life and highlights changes in her community, giving many vignettes of her own work with Aboriginal people. A recurrent theme is the Aboriginal experience of Government control, and the impact of the dreaded Aboriginal Protection Board, which for decades by deliberate policy removed Aboriginal children to institutions and non-Aboriginal foster families. (Editor)     

Power and new economic relationships

We are going through a transformation of our health services from a community and patient focus fueled by fee-for-service and cost-plus reimbursement. This transformation, called managed care, is shifting power away from professionals and communities into both new and old organizations financed by Wall Street. Even traditional community organizations are driven by Wall Street-dictated financial ratios that represent scoreboards to determine who gets capital for growth and development. Times are changing, organizations are changing, and still more change is ahead.