Significance of the Dermal Route of Exposure to Risk Assessment

The skin is a route of exposure that needs to be considered when conducting a risk assessment. It is necessary to identify the potential for dermal penetration by a chemical as well as to determine the overall importance of the dermal route of exposure as compared with inhalation or oral routes of exposure. The physical state of the chemical, vapor or liquid, the concentration, neat or dilute, and the vehicle, lipid or aqueous, is also important. Dermal risk is related to the product of the amounts of penetration and toxicity. Toxicity involves local effects on the skin itself and the potential for systemic effects. Dermal penetration is described in large part by the permeability constant. When permeability constants are not known, partition coefficients can be used to estimate a chemical's potential to permeate the skin. With these concepts in mind, a tiered approach is proposed for dermal risk assessment. A key first step is the determination of a skin-to-air or skin-to-medium partition coefficient to estimate a potential for dermal absorption. Building a physiologically-based pharmacokinetic (PBPK) model is another step in the tiered approach and is useful prior to classical in vivo toxicity tests. A PBPK model can be used to determine a permeability constant for a chemical as well as to show the distribution of the chemical systemically. A detailed understanding of species differences in the structure and function of the skin and how they relate to differences in penetration rates is necessary in order to extrapolate animal data from PBPK models to the human. A study is in progress to examine anatomical differences for four species.     

Lumpers and Splitters: The Public Opinion Information that Politicians Collect and Use

Are the decisions of American policymakers informed by generaltrends in the public’s ideology or by the public’spolicy-specific preferences? In this article we discuss twoexplanations for the types of public opinion information thatpoliticians collect and use. Using a unique data set of privatepolls from the White House of Richard Nixon, we find that whenopinion data on specific policies were available, the presidentrelied on them and not on general ideology data. On less importantissues, however, we find that the president often chose notto collect policy-specific data and instead relied on generalideology data. The differential collection and use of informationby policymakers reflect varying strategic calculations. Theyalso have profound implications for representative democracyand the demands placed on citizens and governors.     

Pathways between education and health: a causal modelling approach

Summary.  The association of poor education and poor health has been consistently observed in many studies and in various countries. Thus far, studies examining the mechanisms underlying this association have looked at only a limited set of potential pathways. This study simultaneously examines six distinctive pathways, which have been hypothesized to link education and health and found support from previous studies. A causal analysis of education and health was performed using structural equation models. Data were used from six phases of the National Child Development Study, which is based on following up an initial sample of 17416 children who were born in 1958. The association between education and health appears to be explained by a combination of mechanisms: adolescent health and adult health behaviours for men and women, adult social class among men and parental social class among women. We conclude that improvements in population educational attainment may not automatically lead to improvements in population health, and that health policies for improving health and reducing health inequalities need to target specific causal pathways.     

Training with o (observing) and T (treatment) teams in live supervision: reflections in the looking glass*

Working with a treatment and observing team at the same time, behind the oneway mirror, offers a variety of ways to: (a) generate multiple realities; (b) work with two different models of family therapy simultaneously; and (c) provide feedback on the teams' own roles, rules and group process. The process that 6 trainees and two supervisors used with T and O teams to examine their own coevolution as a therapeutic system using the Milan model of family therapy and Ericksonian hypnotherapy is described. The article concludes with a discussion of the advantages and pitfalls of this type of dual supervision.     

Socioeconomic, medical care, and public health contexts affecting infant mortality: a study of community-level differentials in Peru

Socioeconomic, medical care, and public health contexts are examined in Peruvian communities for their relationship to infant mortality. A deviant case analysis is used to uncover characteristics important in the social structure of Peruvian communities. Results from fieldwork in two "deviant" communities suggest that economic diversity, income disparity, social class fluidity, and women's autonomy, along with refined measures of medical care and public health resources, are important in understanding differentials in mortality. Attention is drawn to the community context and to the interplay of socioeconomic determinants affecting infant mortality.     

Remittances from labor migration: evaluations,performance and implications

2 evaluative views of worker remittances draw opposite conclusions. The negative one posits that remittances increase dependency, contribute to economic and political stability and development distortion, and lead to economic decline that overshadows a temporary advantage for a fortunate few. The positive view sees remittances as an effective response to market forces, providing a transition to an otherwise unsustainable development. They improve income distribution and quality of life beyond what other available development resources could deliver. The implications are tested for labor supply countries to Europe and the Middle East. The implications of the negative are not supported. Although the dire predictions of the pessimistic view have not materialized, the converse - contributions of remittances to economic performance - should not be overstated due to a lack of data.     

The right to life

In this issue is a lengthy, thought-provoking essay on the issues raised by unwanted pregnancy. Written by Robert Wennberg in 1984 for the Christian Scholar's Review (13:4), the article has been edited and condensed for our purposes and is quite relevant, I believe, for the student health population. Any practitioner who cares for students wrestling with these issues should at least acknowledge the moral and philosophical dilemmas presented. As one who has walked both sides of the argument, I find Wennberg's fair-mindedness compelling. In closing his article, the author raises the question of what will happen when it becomes possible to accomplish an "abortion"--or removal of the fetus from the mother--without killing the fetus. Will this procedure be acceptable to the average single college student? The New York Times, in an article on "High Tech Babies" (February 21, 1986), raised ethical questions posed by the technology of frozen embryos. Who decides what is to be done with frozen embryos? To whom do they belong? Do they have rights? The theoretical issues raised by Wennberg are already forcing themselves upon us. Whether we like it or not, the future is now. Regardless of your beliefs on this controversial topic, I urge you to read this article. Dr. Wennberg has also just completed a book on this subject, Life In The Balance.     

Immigration and the earnings of youth in the U.S.

"This article reports findings that have emerged from an effort made at statistically measuring the effects of immigration on the earnings of U.S.-born youth. The presence of immigrants arriving before 1965 has a positive impact on youth earnings. Recently arrived immigrants impact negatively, however. These results are consistent with recent findings that the skill level of immigrants arriving within the last two decades is lower relative to that of immigrants arriving earlier. The results also show that the negative effects diminish as the youth ages, reflecting skill acquisition and job mobility of the young worker into jobs less vulnerable to competition from immigrant workers."     

The technique of participatory research in community development

The technique of participatory research in community development is based on the involvement of the beneficiaries of the research in the entire research process, including the formulation of the research design, the collection of data, interpretation of information collected, and the analysis of findings. Thus, research teams utilizing this approach are composed of villagers, farmers, unemployed people, local leaders, and educators. The research process thus offers an educational experience that helps to identify community needs and motivate community members to become committed to the solution of their own problems. Moreover, this approach challenges the prevalent notion that only professional researchers can generate knowledge for meaningful social reform. A participatory research technique, based on the concept of citizen enlightenment for community development, was adopted by the Department of Adult Education at the University of Ibadan in a study of rural poverty in Oyo State's Apasan villages. The research team, comprised of local leaders, peasant farmers, teachers, local students, and university students, identified the villages' isolation and food scarcity as major causes of poverty. 2 actions were taken in response to these findings: 1) the construction of a road linking the Apasan communities with the State capital, enabling villagers to travel to the town, sell their goods, and purchase needed items; and 2) formation of a primary cooperative society for multipurpose farming. These actions have solved the food problem, improved the villagers' earning capacity, and resulted in the return of numerous villagers who had migrated to towns to find wage employment. Because the villagers were directly involved in the study of their problems, they were able to become more aware of their social reality and make the changes needed to lift them out of poverty.     

Age difference asymmetry and a two-sex perspective

The paper shows that (a) the age difference between spouses can be and has been different for men and women; (b) male and female age differences can exhibit different trends; (c) the discrepancy is due to remarriage; (d) the age difference fluctuates substantially through time; (e) trends in the age difference are not readily interpretable as reflecting change in the relative status of the sexes; and (f) that trends in the age difference may be linked to marriage market conditions. The paper argues that marriage and fertility data for both men and women are increasingly necessary because of rises in marital breakdown and the associated divergence of the experience of men and women.Cet article montre que (a) les différences d'âge entre époux peuvent être et ont été dissemblables pour les hommes et les femmes; (b) les différences d'âge masculines et féminines peuvent présenter des tendances différentes; (c) la divergence est due aux remariages; (d) les différences d'âge varient de façon importante au cours du temps; (e) les tendances dans les différences d'âge ne sont pas simplement interprétables en termes de changements dans le statut relatif des sexes; et (f) les tendances dans les différences d'âge peuvent être reliées aux conditions du marché matrimonial. L'article montre que les données sur le mariage et la fécondité à la fois des hommes et des femmes, sont de plus en plus nécessaires du fait de l'accroissement des ruptures d'unions et de la divergence des expériences masculines et féminines, qui lui est associée.

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An earlier version of this paper, His and her age gap: asymmetry in the age difference between partners, was a contributed paper to Session F27 of the General Conference of the International Union for the Scientific Study of Population, New Delhi, 20–27 September 1989. A longer version appeared as LS Working Paper 70, issued by City University Social Statistics Research Unit, September 1990.