The distinction between amphibole asbestos fibers and non-asbestos amphibole particles has important implications for assessing potential cancer risks associated with exposure to amphibole asbestos or amphibole-containing products. Exposure to amphibole asbestos fibers can pose a cancer risk due to its ability to reside for long periods of time in the deep lung (i.e., biopersistence). In contrast, non-asbestos amphibole particles are usually cleared rapidly from the lung and do not pose similar respiratory risks even at high doses. Most regulatory and public health agencies, as well as scientific bodies, agree that non-asbestos amphiboles possess reduced biological (e.g., carcinogenic) activity. Although non-asbestos amphibole minerals have been excluded historically from Federal regulations, non-asbestos structures may be counted as asbestos fibers on the basis of dimensional criteria specified in analytical protocols. Given the potential to mischaracterize a non-asbestos structure as a "true" asbestos fiber, our objective was to assess whether exposure to non-asbestos amphiboles that may meet the dimensional criteria for counting as a fiber pose a cancer risk similar to amphibole asbestos. We reviewed analytical methods as well as the mineralogical, epidemiological, and toxicological literature for non-asbestos amphiboles. No evidence of demonstrable cancer effects from exposure to non-asbestos amphiboles that may be counted as fibers, under certain assessment protocols, was found. Data gaps (industrial hygiene data for amphibole-exposed cohorts), inconsistencies (analytical laboratory methods/protocols used to count fibers), and sources of potential bias from misclassification of exposure were identified.

Disparities between racially minoritized (Black/Hispanic/Native American) and nonminoritized (White/Asian) students in educational outcomes—both in terms of opportunity and achievement—continue to characterize the American educational system. Social belonging interventions, which shift student construal of social adversity experienced in school, have been shown to be effective with college students (Walton & Cohen, 2011) but have not been tested with high school students. We developed and tested such an intervention in a randomized controlled trial with students transitioning from middle school into high school. Participants (N = 162; 18% minoritized, 79% nonminoritized, 57% women) were randomly assigned to receive intervention or control materials during an optional summer orientation program. By the end of their first year, students in the treatment condition had 46% fewer unexcused absences (95% CI [−66%, −15%]), 36% fewer tardiness records (95% CI [−63%, 12%]), and gained more friends (d = 0.59) than did participants in the control condition. The intervention was particularly effective for racially minoritized participants: Those in the treatment condition failed fewer classes (d = −0.86), earned higher grades (d = 0.90), and received 82% fewer disciplinary citations (95% CI [−97%, 26%]) by the end of the academic year than did their minoritized peers in the control condition. These gains represent reductions in racial gaps ranging from 86% to 100%. Our findings indicate that social belonging interventions might partially redress racial equity gaps in secondary education. Discussion centers on the potential psychological and behavioral mechanisms underlying the intervention.

Undergraduate students in science, technology, engineering, and mathematics (STEM) programs face unique challenges to their psychological well-being, including their sense of belonging.Recent evidence suggests that beliefs about the malleability of intelligence (growth mindsets) support STEM students' belongingness, though the mechanisms of this relationship are unclear.We propose and test a model in which students' personal growth mindset beliefs relate to their sense of belonging by operating as a filter of environmental cues, especially those signaling instructors' mindsets, peers' mindsets, and the overall trustworthiness of the school. Across more than 3,000 students in two diverse STEM contexts, we found general support for this model (mean RMSEA = 0.041; mean R 2 = 39%). Perceived environmental cues explained 100% (Study 1) and 35% (Study 2) of the total effect of personal growth mindset on belonging. In addition to model generalizability, there was meaningful heterogeneity in the results observed across contexts. These results suggest a novel filtering function of growth mindsets in addition to the importance of perceptions of instructors' growth mindsets and school trust for belonging.Discussion centers on the factors that may account for model variability, as well as theoretical and practical implications of the findings.

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