Correlations between risk perceptions and risk behaviors are used by investigators to answer 2 important and easily confused questions: Are individuals' perceptions of their personal risk accurate, correctly reflecting their precautions and their risk-increasing behaviors? and Does recognition of high personal risk cause people to adopt precautions to reduce that risk? Researchers who use survey data to investigate these questions often look at the wrong correlations to get their answers. Furthermore, as members of a population adopt precautions and change their risk status, correlations between perceived risk and risk behavior in this population also change. A mathematical model of precaution adoption--allowing a bidirectional relationship between perception and behavior--is used to illustrate the different correlations between risk perception and risk behavior that can be examined and the changes in correlations that can occur with the passage of time. Recommendations are provided concerning the correlations most appropriate for answering each of the 2 preceding questions. Which correlation is appropriate to answer the second question varies depending on whether a study is begun before people have taken precautions or after ample time to take precautions has already passed.

We assessed the effectiveness of an emotion induction procedure for the study of emotional communication in adults; we also gathered preliminary age-comparative data on the expressive and receptive capacities of a sample of adult women. Young, middle-aged, and older women (encoders) related emotional experiences following mood induction and then assessed the intensity of their affective experiences. Videotapes of these sessions (facial expressions only) were shown to young, middle-aged, and older female judges (decoders), who rated the encoders for emotional intensity as well as for type of affect being communicated. Validity and reliability issues with respect to the procedure's usefulness are discussed. Decoding accuracy was found to vary with age congruence between encoder and decoder, suggesting a decoding advantage accruing through social contact with like-aged peers. Older decoders did most poorly, but a differential warm-up effect was evident, suggesting that the performance of older subjects might be enhanced with practice. There were also trends suggesting that the affective expressions of older subjects may be harder to decode owing to age-related structural changes in the face. Results are discussed in the context of theoretical models of affective development.

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Scientific literacy reflects "a broad and functional understanding of science for general education purposes" (DeBoer, 2000, p. 594). Herein, we present the ongoing development of the Scientific Literacy Assessment (SLA), a work-in-progress measure to assess middle school students' (ages 11-14) scientific literacy. The SLA includes a selected response measure of students' demonstrated scientific literacy (SLA-D) and a motivation and beliefs scale based on existing measures of self-efficacy, subjective task value, and personal epistemology for science (SLA-MB). Our theoretical conceptualization of scientific literacy guided the development of our measure. We provide details from three studies: Pilot Study 1 (n = 124) and Pilot Study 2 (n = 220) describe the development of the SLA-D by conducting iterative item analyses of the student responses, think-aloud interviews with six students, and external expert feedback on the items in the SLA-D. Study 3 describes the testing of our prototype measure (n = 264). We present a validity argument including reliability evidence that supports the use of the current version of the SLA to provide evaluation of middle school students' scientific literacy. Our resulting SLA includes the SLA-D in two versions, each with 26 items and the SLA-MB with 25 items across three scales: value of science, scientific literacy self-efficacy, and personal epistemology. C 2014 Wiley Periodicals, Inc. Sci Ed 98:549-580, 2014

Aims:To assess mortality and cancer morbidity in Canadian petroleum workers and explore exposure-response relations for specific petroleum agents.Methods:A total of 25 292 employees hired between 1964 and 1994 were linked to the Canadian tumour registry and national mortality database. Exposure-response trends were assessed for hydrocarbon solvents/fuels, hydrocarbon lubricants, petroleum coke/spent catalyst, and hydrogen sulphide (H2S).Results:External comparison analyses (mortality and incidence) showed deficits for all causes and all malignant neoplasms combined and were consistent with expectation for most malignant and non-malignant sites analysed. Gall bladder cancer mortality was increased among males based on four deaths, but cases had no common job assignments and the increase was focused in workers employed <10 years. Mesothelioma incidence was increased. Most exposure-specific analyses were compromised by small numbers. Statistically significant increases were observed for H2S exposure and a subgroup of accidental deaths as well as for petroleum coke/spent catalyst exposure and lung cancer. While both findings have a degree of biologic plausibility, the H2S association, which exhibited a clearer exposure-response pattern, could be subject to unmeasured confounders. Additionally, interpretation was complicated by the high correlation between hydrocarbon and H2S exposures. With regard to lung cancer, the analysis could not adequately control for smoking, was based on small numbers, and exhibited a tenuous exposure-response pattern.Conclusion:The findings for mesothelioma suggest the need for continued attention to asbestos in the petroleum industry. The relation between accidental deaths and H2S exposure deserves closer scrutiny in similarly exposed populations. Further analyses of lung cancer are underway and will be reported separately.

Objective-To evaluate the relation between mortality from lymphohaematopoietic cancer and long term, low level exposures to benzene among male petroleum distribution workers. Methods-This nested case control study identified all fatal cases of lymphohaematopoietic cancer among a previously studied cohort. Of the 29 cases, 14 had leukaemia, seven multiple myeloma, and eight non-Hodgkin's lymphoma. A four to one matching ratio was used to select a stratified sample of controls from the same cohort, controlling for year of birth and time at risk. Industrial hygienists estimated workplace exposures for benzene and total hydrocarbons, without knowledge of case or control status, for combinations of job, location, and era represented in all work histories. Average daily benzene concentrations ranged from

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We conducted a retrospective mortality study among 6672 petroleum marketing and distribution workers from 226 locations throughout Canada. These employees worked for at least 1 year in the marketing distribution segment from 1964 through 1983 or were annuitants as of 1964. Industrial hygienists assigned hydrocarbon (HC) exposure frequency scores for several jobs, departments, and job functions. We computed standardized mortality ratios for the total cohort, HC exposure frequency groups, and tank truck drivers, and we also used Poisson regression techniques to model mortality for selected causes of death according to HC exposure frequency. Results indicate overall mortality below that of the general Canadian population for all marketing distribution workers [Standardized mortality ratio (SMR) = 0.88]. Mortality from aortic aneurysms was significantly elevated in all marketing/distribution workers (SMR = 1.79) but was due to raised mortality in nonexposed workers (SMR = 2.80). Tank truck drivers showed significantly elevated mortality due to leukemia (SMR = 3.35) based on five deaths. The leukemia findings were not evident in the larger group of marketing distribution workers classified as exposed to hydrocarbons (SMR = 1.01). No other cause ofdeath was elevated in truck drivers. The leukemia findings are suggestive of a possible influence due to exposure to HCs in tank truck drivers, although other explanations cannot be ruled out. Other findings of elevated mortality in the marketing distribution group are generally not statistically significant. These included moderately increased mortality due to multiple myeloma, malignant melanoma, and kidney cancer. Small numbers of observed and expected deaths limit concise interpretations for these diseases.