Industry-wide review of potential worker exposure to 1,3-butadiene during chemical manufacturing and processing as a reactant.

Among the first 20 high-priority chemical substances selected by USEPA to undergo risk evaluation as part of the Toxic Substances Control Act, as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act of 2016 is 1,3-butadiene (1,3-BD). Because much of the literature related to occupational exposure to 1,3-BD is associated with the use of the substance in synthetic rubber production and few data have been published for exposures to 1,3-BD manufacturing workers, existing industrial hygiene data collected at facilities where the substance is manufactured or processed as a reactant were compiled and analyzed. The dataset was comprised of personal air samples collected between 2010 and 2019 at facilities located throughout the United States and was compiled into a single database using a uniform data collection template. Data designated by the companies as full-shift were stratified by job group and one of three operational conditions of the workplace: routine, turnaround, and non-routine. Data designated by the companies as short-term and task-level were stratified by task description, sample duration, and operational condition. The final aggregated database contained a total of 5,676 full-shift personal samples. Mean concentrations of 1,3-BD for the job groups ranged from 0.012 ppm to 0.16 ppm. High-end estimates of 1,3-BD air concentrations for the job groups under routine operations ranged from 0.014 ppm to 0.23 ppm. The aggregated database also included 1,063 short-term and task-level personal samples. For short-term samples (< =15 min), mean concentrations ranged from 0.49 ppm to 3.9 ppm, with the highest concentrations observed for the cleaning and maintaining equipment tasks. For task samples with durations greater than 15 min, mean concentrations ranged from 0.49 to 3.6 ppm, with the highest concentrations observed for the unloading and loading task. In addition to the personal air sampling records, information on the use of PPE during various tasks was compiled and analyzed. This data set provides robust quantitative air concentration data and exposure control information for which occupational exposures to 1,3-BD in the Manufacturing and Processing as a Reactant condition of use can be assessed.

Cannabidiol Safety Data: A Systematic Mapping Study.

Robust assessment of potential adverse outcomes is needed to determine a safe cannabidiol (CBD) intake level for consumer use. To assist in identifying knowledge gaps and inform future decision making regarding systematic development of health-based benchmarks, we have developed the first systematic map of the safety-related information available for CBD in the peer-reviewed literature. Literature searching conducted according to a published protocol yielded a total of 4186 unique titles and abstracts published through 2020. These were screened using DistillerSR for studies that evaluated at least one potential health outcome following exposure to CBD and/or other hemp-derived substances. Additional categorization was conducted for a subset of 1001 studies in which CBD was administered alone. Studies that investigated CBD most frequently reported on neurological outcomes (532), carcinogenic outcomes (129), and pharmacokinetics (118). Less frequently studied categories included developmental and reproductive, hepatic, and gastrointestinal outcomes. The primary outcomes associated with the most adverse events reported in the literature were neurological (13) and developmental and reproductive (12). Based on the studies identified, reproductive and developmental toxicity was identified as a data gap that warrants conducting a well-designed, guideline-compliant reproductive toxicity study on CBD. In addition, immune outcomes were noted as a potential emerging research area for CBD. This systematic map provides an important baseline from which to identify topics that may be suitable for further research related to the safe use of CBD. Implications for future potential work and limitations of the mapping exercise are discussed.

Drivers of Scope of Practice in Family Medicine: A Conceptual Model.

PURPOSE: The purpose of this study was to explore family medicine graduates' attitudes and perspectives on modifiable and unmodifiable factors that influenced their scope of practice and career choices. By understanding how these factors intersect to influence desired and actual scope of practice decisions, we hope to inform strategies to address training and health care workforce needs. METHODS: During 5 focus group discussions, comprised of a total of 32 family physicians who either resided in or attended a residency program in western North Carolina, we explored family physicians' attitudes and perspectives on their desired and actual scope of practice. We used thematic analysis to identify patterns in the qualitative data. RESULTS: We created a conceptual framework to understand the complex factors which influence family physicians' scope of practice. Personal factors were found to impact desired scope, while workplace, environmental, and population factors influenced actual scope of practice. Stressors in each of these 4 categories often caused family physicians to narrow their scope of practice. Our study highlights specific supports that, if in place, enable physicians to maintain their desired broad scope of practice. CONCLUSIONS: Our study indicates that the national trend toward family physicians narrowing their scope of practice can be addressed by providing specific supports during training, residency, and mid-career. Understanding personal, workplace, environmental, and population factors that influence scope of practice can inform specific interventions that create desirable jobs for family physicians and improve their ability to meet changing population needs.

Evaluation of potential human health risk associated with consumption of edible products from livestock fed ration supplemented with Red Lake Diatomaceous Earth.

Red Lake Diatomaceous Earth (DE) is a naturally occurring blend of diatomaceous earth and calcium bentonite that can be used as an anti-caking agent in animal feed and contains naturally occurring dioxins. A quantitative risk assessment was conducted to assess potential human health risk associated with consumption of edible tissues from livestock exposed to dioxins via feed containing Red Lake DE. Empirical data characterising the transfer of dioxins to eggs and other tissues in chickens demonstrate that resulting concentrations in eggs are lower than those found in the general food supply. These data also provided product-specific input for a risk assessment conducted both with default parameters and with media-specific input from the feed study. Results demonstrate that exposure to dioxins in edible tissue from livestock that consumed Red Lake DE in feed would not be associated with an increased risk to humans. Findings from this assessment highlight the utility and importance of accounting for bioavailability as part of health-based risk assessment and provide information critical to risk managers in determining the safe use of Red Lake DE as an anticaking agent in livestock and pet feed.

Key Findings and Implications of a Recent Systematic Review of the Potential Adverse Effects of Caffeine Consumption in Healthy Adults, Pregnant Women, Adolescents, and Children.

In 2016⁻2017, we conducted and published a systematic review on caffeine safety that set out to determine whether conclusions that were presented in the heavily cited Health Canada assessment, remain supported by more recent data. To that end, we reviewed data from 380 studies published between June 2001 and June 2015, which were identified from an initial batch of over 5000 articles through a stringent search and evaluation process. In the current paper, we use plain language to summarize our process and findings, with the intent of sharing additional context for broader reach to the general public. We addressed whether caffeine doses previously determined not to be associated with adverse effects by Health Canada (400 mg/day for healthy adults, 300 mg/day for pregnant women, 2.5 mg/kg body weight/day for adolescents and children, and 10 g/day for acute effects) remain appropriate for five outcome areas (acute toxicity, cardiovascular toxicity, bone & calcium effects, behavior, and development and reproduction) in healthy adults, pregnant women, adolescents, and children. We used a weight-of-evidence approach to draw conclusions for each of the five outcomes, as well as more specific endpoints within those outcomes, which considered study quality, consistency, level of adversity, and magnitude of response. In general, updated evidence confirms the levels of intake that were put forth by Health Canada in 2003 as not being associated with any adverse health effects, and our results support a shift in caffeine research from healthy to sensitive populations.

Government and Navy knowledge regarding health hazards of asbestos: a state of the science evaluation (1900 to 1970).

We evaluated dozens of published and unpublished documents describing the knowledge and awareness of both the scientific community and governmental entities, particularly the US Navy, regarding the health hazards associated with asbestos over time. We divided our analysis into specific blocks of time: 1900-1929, 1930-1959, and 1960-1970. By 1930, it was clear that high occupational exposure to asbestos caused a unique disease (asbestosis). Between about 1938 and 1965, a considerable amount of exposure and epidemiology data were collected by various scientific and government organizations. Between 1960 and 1970, mesothelioma was clearly linked to exposure to amphibole asbestos. Nonetheless, the Navy continued to require the use of asbestos-containing materials on ships, but also recommended that proper precautions be taken when handling asbestos. We concluded that the Navy was arguably one of the most knowledgeable organizations in the world regarding the health hazards of asbestos, and that it attempted to implement procedures that would minimize the opportunity for adverse effects on both servicemen and civilians. Finally, it is apparent from our research that through at least 1970, neither the military nor the private sector believed that the myriad of asbestos-containing products considered "encapsulated" (e.g. gaskets, brakes, Bakelite) posed a health hazard to those working with them.