Development of a Unit Risk Factor for 1,3-Butadiene Based on an Updated Carcinogenic Toxicity Assessment

The Texas Commission on Environmental Quality (TCEQ) has developed an inhalation unit risk factor (URF) for 1,3-butadiene based on leukemia mortality in an updated epidemiological study on styrene-butadiene rubber production workers conducted by researchers at the University of Alabama at Birmingham. Exposure estimates were updated and an exposure estimate validation study as well as dose-response modeling were conducted by these researchers. This information was not available to the U.S. Environmental Protection Agency when it prepared its health assessment of 1,3-butadiene in 2002. An extensive analysis conducted by TCEQ discusses dose-response modeling, estimating risk for the general population from occupational workers, estimating risk for potentially sensitive subpopulations, effect of occupational exposure estimation error, and use of mortality rates to predict incidence. The URF is 5.0 × 10⁻⁷ per μg/m³ or 1.1 × 10⁻⁶ per ppb and is based on a Cox regression dose-response model using restricted continuous data with age as a covariate, and a linear low-dose extrapolation default approach using the 95% lower confidence limit as the point of departure. Age-dependent adjustment factors were applied to account for possible increased susceptibility for early life exposure. The air concentration at 1 in 100,000 excess leukemia mortality, the no-significant-risk level, is 20 μg/m³ (9.1 ppb), which is slightly lower than the TCEQ chronic reference value of 33 μg/m³ (15 ppb) protective of ovarian atrophy. These values will be used to evaluate ambient air monitoring data so the general public is protected against adverse health effects from chronic exposure to 1,3-butadiene.     

Use of Professional and Informal Support by Black Men with Mental Disorders

This study utilized data from the National Survey of American Life to investigate the use of professional services and informal support among African American and Caribbean black men with a lifetime mood, anxiety, or substance use disorder. Thirty-three percent used both professional services and informal support, 14% relied on professional services only, 24% used informal support only, and 29% did not seek help. African American men were more likely than to rely on informal support alone. Having co-occurring mental and substance disorders, experiencing an episode in the past 12 months, and having more people in the informal network increased the likelihood of using professional services and informal supports. Marital status, age, and socioeconomic status were also significantly related to help-seeking. The results suggests potential unmet need. However, the reliance on informal support also suggests a strong protective role that informal networks play in the lives of black men.     

Future state visioning—A powerful leadership process

The process of conceptualizing and implementing significant change in complex organizations can be aided greatly through ‘future state visioning’, a set of processes for determining what and where you want to be by a future date. After developing ideas about the nature of the future environment facing the organization and the stakeholders who will be significant at that time, executives can articulate the values and principles which should guide actions leading to the future state vision. Examples from three organizations are used to illustrate the steps for successful use of the future state visioning procedure.     

Experiment-dependent priors in psychology and physics

Sometimes conducting an experiment to ascertain the state of a system changes the state of the system being measured. Kahneman & Tversky modelled this effect with support theory. Quantum physics models this effect with probability amplitude mechanics. As this paper shows, probability amplitude mechanics is similar to support theory. Additionally, Viscusi's proposed generalized expected utility model has an analogy in quantum mechanics.     

The Interaction Between Role Structures and Self-Conceptions in Fostering Different Types of Self-Esteem in Innovative and Traditional Elementary Schools*

A two-dimensional model of inner and outer self-esteem is discussed wherein inner self-esteem is hypothesized to be an outcome of self-evaluations of performance in prominent role identities. Outer self-esteem is hypothesized to be related to self-evaluations of both prominent and nonprominent role identities. The research context is a comparison of the different processes facilitating self-esteem in innovative schools (emphasis on student-initiated activities and control) and traditional (emphasis on pre-determined curriculum and teacher-administrator control). Data across school type demonstrate a modest correlation between positive self-evaluations of performance in prominent role identities and both types of self-esteem. The data suggest that high evaluation of performance in nonprominent role identities is related to outer self-esteem but not to inner self-esteem. Further empirical clarification of the concepts was established by viewing the relationships within school type. In the innovative schools both types of self-esteem were predominantly related to positive evaluations of prominent role identities, whereas in the traditional schools both types of self-esteem were related to both performance in prominent and nonprominent role identities. Thus the theoretical distinction gained partial support while the process of gaining self-esteem was shown to be essentially different between alternate school structures. Controls for social desirability, race, sex, and father's occupation did not change these findings.     

Processes of adjustment in organized out-of-school activities: opportunities and risks

Participation in organized out-of-school activities leads to long-term psychosocial and educational benefits for young people. Now we're learning which features of these activities best support individual children.