Advancing the community health vulnerability index for wildland fire smoke exposure

Wildland fire smoke risks are not uniformly distributed across people and places, and the most vulnerable communities are often disproportionately impacted. This study develops a county level community health vulnerability index (CHVI) for the Contiguous United States (CONUS) using three major vulnerability components: adaptive capacity, sensitivity, and exposure at the national and regional level. We first calculated sensitivity and adaptive capacity sub-indices using nine sensitivity and twenty adaptive capacity variables. These sub-indices were then combined with an exposure sub-index, which is based on the Community Multiscale Air Quality data (2008-2018), to develop CHVI. Finally, we conducted several analyses with the derived indices to: 1) explore associations between the level of fine particulate matter from wildland fires (fire-PM2.5) and the sub-indices/CHVI; 2) measure the impact of fire-PM2.5 on the increase in the annual number of days with 12-35 μg/m3 (moderate) and >35 μg/m3 (at or above unhealthy for sensitive groups) based on the US EPA Air Quality Index categories, and 3) calculate population size in different deciles of the sub-indices/CHVI. This study has three main findings. First, we showed that the counties with higher daily fire-PM2.5 concentration tend to have lower adaptive capacity and higher sensitivity and vulnerability. Relatedly, the counties at high risk tended to experience a greater increase in the annual number of days with 12-35 μg/m3 and >35 μg/m3 than their counterparts. Second, we found that 16.1, 12.0, and 17.6 million people out of 332 million in CONUS reside in the counties in the lowest adaptive capacity decile, highest sensitivity decile, and highest vulnerability decile, respectively. Third, we identified that the US Northwest, California, and Southern regions tended to have higher vulnerability than others. Accurately identifying a community's vulnerability to wildfire smoke can help individuals, researchers, and policymakers better understand, prepare for, and respond to future wildland fire events.

Occupational heat-related illness in Washington State: A descriptive study of day of illness and prior day ambient temperatures among cases and clusters, 2006-2021

BACKGROUND

Insufficient heat acclimatization is a risk factor for heat-related illness (HRI) morbidity, particularly during periods of sudden temperature increase. We sought to characterize heat exposure on days before, and days of, occupational HRIs.

METHODS

A total of 1241 Washington State workers' compensation State Fund HRI claims from 2006 to 2021 were linked with modeled parameter-elevation regressions on independent slopes model (PRISM) meteorological data. We determined location-specific maximum temperatures (Tmax,PRISM ) on the day of illness (DOI) and prior days, and whether the Tmax,PRISM was ≥10.0°F (~5.6°C) higher than the average of past 5 days ("sudden increase") for each HRI claim. Claims occurring on days with ≥10 HRI claims ("clusters") were compared with "non-cluster" claims using t tests and χ2 tests.

RESULTS

Seventy-six percent of analyzed HRI claims occurred on days with a Tmax,PRISM  ≥ 80°F. Claims occurring on "cluster" days, compared to "non-cluster" days, had both a significantly higher mean DOI Tmax,PRISM (99.3°F vs. 85.8°F [37.4°C vs. 29.9°C], t(148) = -18, p < 0.001) and a higher proportion of "sudden increase" claims (80.2% vs. 24.3%, χ2 [1] = 132.9, p < 0.001). Compared to "cluster" days, HRI claims occurring during the 2021 Pacific Northwest "heat dome" had a similar increased trajectory of mean Tmax,PRISM on the days before the DOI, but with higher mean Tmax,PRISM. CONCLUSIONS: Occupational HRI risk assessments should consider both current temperatures and changes in temperatures relative to prior days. Heat prevention programs should include provisions to address acclimatization and, when increases in temperature occur too quickly to allow for sufficient acclimatization, additional precautions.

The Effect of Participatory Heat Education on Agricultural Worker Knowledge

OBJECTIVES

Farmworkers disproportionately experience preventable adverse health effects from heat exposure. We sought to evaluate the effect of participatory heat education on farmworker knowledge.

METHODS

We conducted a parallel, comparison group intervention study to investigate the effectiveness of a Spanish/English participatory, culturally-tailored, heat education-based intervention on farmworker heat knowledge in the Summer 2019. We used convenience sampling to recruit adult outdoor farmworkers from Central/Eastern Washington State, USA. Crews were randomized to receive the intervention (n = 40 participants) versus not receive the intervention (n = 43 participants). We assessed changes in heat knowledge, scored on a scale from 0 to 11, between baseline, immediate post-intervention, and post-season, which was approximately three months after baseline, using the Wilcoxon signed-rank test. We compared differences in knowledge scores from baseline to post-season between groups using analysis of variance.

RESULTS

Average knowledge scores improved from 4.6 (standard deviation [sd] 1.5) to 6.3 (sd 2.0) pre to post season in the intervention group (p < 0.001). There was a greater improvement in pre-post knowledge scores in the intervention (average difference 1.6, sd 2.0) versus the comparison group (average difference 0.41, sd 1.7) (p = 0.04).

CONCLUSIONS

Participatory heat training was effective in improving farmworker heat knowledge over the course of a summer season. Results of this study will be used to guide heat prevention efforts for farmworkers.

TRIAL REGISTRATION

ClinicalTrials.gov Registration Number: NCT04234802.

Intensity of physical therapy services: Association with work and health outcomes in injured workers with back pain in Washington State

BACKGROUND

Associations between the intensity of physical therapy (PT) treatments and health outcomes among individuals with back pain have been examined in the general population; however, few studies have explored these associations in injured workers. Our study objective was to examine whether intensity of PT treatments is positively associated with work and health outcomes in injured workers with back pain.

METHODS

We conducted a secondary analysis of prospective data collected from the Washington State Workers' Compensation (WC) Disability Risk Identification Study Cohort (D-RISC). D-RISC combined survey results with WC data from the Washington State Department of Labor and Industries. Workers with a State Fund WC claim for back injuries between June 2002 and April 2004 and who received PT services within the first year of injury were eligible. Intensity of PT treatment was measured as the type and amount of PT services within 28 days from the first PT visit. Outcome measures included work disability and self-reported measures for working for pay, pain intensity, and functional status at 1-year follow-up. We conducted linear and logistic regression models to test associations.

RESULTS

We identified 662 eligible workers. In adjusted models, although the intensity of PT treatment was not significantly associated with work disability at 1-year follow-up, it was associated with lower odds of working for pay, decreased pain intensity, and improved functional status.

CONCLUSIONS

Our findings suggest that there may be small benefits from receiving active PT, manual therapy, and frequent PT treatments within 28 days of initiating PT care.

"When people see me, they know me; they trust what I say": characterizing the role of trusted sources for smoke risk communication in the Okanogan River Airshed Emphasis Area

INTRODUCTION

As wildfire smoke events increase in intensity and frequency in the Pacific Northwest, there is a growing need for effective communication on the health risks of smoke exposure. Delivery through a trusted source or intermediary has been shown to improve reception of risk communication messages. This is especially salient in rural and tribal communities who may be hesitant to trust information from state and federal agency sources. This study aims to identify and characterize trusted sources for smoke risk information in the Okanogan River Airshed Emphasis Area (ORAEA), a rural region of North Central Washington state that is heavily impacted by smoke from wildfires and prescribed fire.

METHODS

The research team conducted a qualitative study using data collected through key informant interviews and focus groups to assess the role of various sources and intermediaries in disseminating smoke risk information. We used a consensual coding approach in NVivo Qualitative Analysis Software to sort data into preliminary categories, which were grouped into themes using a thematic analysis approach. We used member checking and iterative feedback processes with local project partners throughout the project to ensure credibility of results.

RESULTS

Through the analysis, we identified three themes characterizing trusted sources for smoke risk communication in the ORAEA. These themes were: (1) local and tribal sources of information are perceived as more trustworthy than state and federal government sources, (2) trustworthiness is determined by an evaluation of multiple factors, in particular, perceived credibility, quality of information, and relationship with the source, and (3) conservative political ideology and perceived parallels with COVID-19 communication influence perception of trust. Within each theme, we identified several sub-themes, which contributed additional nuance to our analysis.

CONCLUSION

This study provides insights into which sources of information are trusted by rural and tribal community members in the ORAEA and why. Results from our study emphasize the importance of relationships and collaboration with local and tribal partners in smoke risk communication. In this paper, we discuss implications for state and federal agency practitioners and present recommendations for how to work with local and tribal partners on smoke risk communication.

Workplace Determinants of Depression, Anxiety, and Stress in U.S. Mariners during the COVID-19 Pandemic

United States (U.S.) mariners continued sailing throughout COVID-19. Many aspects of their work could make them prone to adverse mental health outcomes but research on workplace determinants of their mental health during COVID-19 is limited. Between January and July 2021 an online survey assessed the outcomes of increased depressive symptoms, increased anxiety symptoms, and increased perceived stress in addition to concerns, worries, and experiences when sailing during COVID-19, job satisfaction, and safety climate in n = 1384 U.S. mariners. Demographic measures were also collected. Logistic regression models (for depression and anxiety) and a linear regression model (for stress) were developed. We found that increased COVID-19 concerns and poor self-reported mental health were related to increased odds of likely depression and anxiety and higher stress. Mariners who experienced more adverse experiences aboard a vessel had increased stress and increased odds of depression. Poor sleep quality was also related to increased odds of depression, and poor vessel support/safety culture was related to higher stress. Differences in outcomes were seen by vessel type, age, and credential in regression analyses. Results from this study will help to prioritize interventions to minimize the mental health impacts of COVID-19, and influence evidence-based recommendations to improve the mental health of mariners going forward.

The effect of the participatory heat education and awareness tools (HEAT) intervention on agricultural worker physiological heat strain: results from a parallel, comparison, group randomized study

BACKGROUND

Farmworkers are at risk of heat-related illness (HRI). We sought to: 1) evaluate the effectiveness of farmworker Spanish/English participatory heat education and a supervisor decision-support mobile application (HEAT intervention) on physiological heat strain; and 2) describe factors associated with HRI symptoms reporting.

METHODS

We conducted a parallel, comparison group intervention study from May-September of 2019 in Central/Eastern Washington State, USA. We used convenience sampling to recruit adult outdoor farmworkers and allocated participating crews to intervention (n = 37 participants) and alternative-training comparison (n = 38 participants) groups. We measured heat strain monthly using heart rate and estimated core body temperature to compute the maximum work-shift physiological strain index (PSI_max) and assessed self-reported HRI symptoms using a weekly survey. Multivariable linear mixed effects models were used to assess associations of the HEAT intervention with PSI_max, and bivariate mixed models were used to describe factors associated with HRI symptoms reported (0, 1, 2+ symptoms), with random effects for workers.

RESULTS

We observed larger decreases in PSI_max in the intervention versus comparison group for higher work exertion levels (categorized as low, low/medium-low, and high effort), after adjustment for maximum work-shift ambient Heat Index (HI_max), but this was not statistically significant (interaction - 0.91 for high versus low/medium-low effort, t = - 1.60, p = 0.11). We observed a higher PSI_max with high versus low/medium-low effort (main effect 1.96, t = 3.81, p < 0.001) and a lower PSI_max with older age (- 0.03, t = - 2.95, p = 0.004), after covariate adjustment. There was no clear relationship between PSI_max and the number of HRI symptoms reported. Reporting more symptoms was associated with older age, higher HI_max, 10+ years agricultural work, not being an H-2A guest worker, and walking > 3 min to get to the toilet at work.

CONCLUSIONS

Effort level should be addressed in heat management plans, for example through work/rest cycles, rotation, and pacing, in addition to education and other factors that influence heat stress. Both symptoms and indicators of physiological heat strain should be monitored, if possible, during periods of high heat stress to increase the sensitivity of early HRI detection and prevention. Structural barriers to HRI prevention must also be addressed.

TRIAL REGISTRATION

ClinicalTrials.gov Registration Number: NCT04234802 , date first posted 21/01/2020.

Potential Impacts of Different Occupational Outdoor Heat Exposure Thresholds among Washington State Crop and Construction Workers and Implications for Other Jurisdictions

Occupational heat exposure is associated with substantial morbidity and mortality among outdoor workers. We sought to descriptively evaluate spatiotemporal variability in heat threshold exceedances and describe potential impacts of these exposures for crop and construction workers. We also present general considerations for approaching heat policy-relevant analyses. We analyzed county-level 2011-2020 monthly employment (Bureau of Labor Statistics Quarterly Census of Employment and Wages) and environmental exposure (Parameter-elevation Relationships on Independent Slopes Model (PRISM)) data for Washington State (WA), USA, crop (North American Industry Classification System (NAICS) 111 and 1151) and construction (NAICS 23) sectors. Days exceeding maximum daily temperature thresholds, averaged per county, were linked with employment estimates to generate employment days of exceedances. We found spatiotemporal variability in WA temperature threshold exceedances and crop and construction employment. Maximum temperature exceedances peaked in July and August and were most numerous in Central WA counties. Counties with high employment and/or high numbers of threshold exceedance days, led by Yakima and King Counties, experienced the greatest total employment days of exceedances. Crop employment contributed to the largest proportion of total state-wide employment days of exceedances with Central WA counties experiencing the greatest potential workforce burden of exposure. Considerations from this analysis can help inform decision-making regarding thresholds, timing of provisions for heat rules, and tailoring of best practices in different industries and areas.

Wildfire, Smoke Exposure, Human Health, and Environmental Justice Need to be Integrated into Forest Restoration and Management

PURPOSE OF REVIEW

Increasing wildfire size and severity across the western United States has created an environmental and social crisis that must be approached from a transdisciplinary perspective. Climate change and more than a century of fire exclusion and wildfire suppression have led to contemporary wildfires with more severe environmental impacts and human smoke exposure. Wildfires increase smoke exposure for broad swaths of the US population, though outdoor workers and socially disadvantaged groups with limited adaptive capacity can be disproportionally exposed. Exposure to wildfire smoke is associated with a range of health impacts in children and adults, including exacerbation of existing respiratory diseases such as asthma and chronic obstructive pulmonary disease, worse birth outcomes, and cardiovascular events. Seasonally dry forests in Washington, Oregon, and California can benefit from ecological restoration as a way to adapt forests to climate change and reduce smoke impacts on affected communities.

RECENT FINDINGS

Each wildfire season, large smoke events, and their adverse impacts on human health receive considerable attention from both the public and policymakers. The severity of recent wildfire seasons has state and federal governments outlining budgets and prioritizing policies to combat the worsening crisis. This surging attention provides an opportunity to outline the actions needed now to advance research and practice on conservation, economic, environmental justice, and public health interests, as well as the trade-offs that must be considered. Scientists, planners, foresters and fire managers, fire safety, air quality, and public health practitioners must collaboratively work together. This article is the result of a series of transdisciplinary conversations to find common ground and subsequently provide a holistic view of how forest and fire management intersect with human health through the impacts of smoke and articulate the need for an integrated approach to both planning and practice.

Consistent cooling benefits of silvopasture in the tropics

Agroforestry systems have the potential to sequester carbon and offer numerous benefits to rural communities, but their capacity to offer valuable cooling services has not been quantified on continental scales. Here, we find that trees in pasturelands (“silvopasture”) across Latin America and Africa can offer substantial cooling benefits. These cooling benefits increase linearly by −0.32 °C to −2.4 °C per 10 metric tons of woody carbon per hectare, and importantly do not depend on the spatial extent of the silvopasture systems. Thus, even smallholders can reap important cooling services from intensifying their silvopasture practices. We then map where realistic (but ambitious) silvopasture expansion could counteract a substantial fraction of the local projected warming in 2050 due to climate change. Our findings indicate where and to what extent silvopasture systems can counteract local temperature increases from global climate change and help vulnerable communities adapt to a warming world.

A new study shows that tropical silvopasture systems can provide significant cooling services for local communities, and identifies where these silvopasture systems can most effectively counteract global climate change to help communities adapt to warming.

Accuracy of an estimated core temperature algorithm for agricultural workers

There is a substantial burden of occupational health effects from heat exposure. We sought to assess the accuracy of estimated core body temperature (CBT_est) derived from an algorithm that uses sequential heart rate and initializing CBT,¹ compared with gastrointestinal temperature measured using more invasive ingestible sensors (CBT_gi), among outdoor agricultural workers. We analyzed CBT_est and CBT_gi data from Washington State, USA, pear and apple harvesters collected across one work shift in 2015 (13,413 observations, 35 participants) using Bland Altman methods. The mean (standard deviation, range) CBT_gi was 37.7 (0.4, 36.5-39.4)°C. Overall CBT bias (limits of agreement) was -0.14 (±0.76)°C. Biases ranged from -0.006 to -0.75 °C. The algorithm, which does not require the use of ingestible sensors, may be a practical tool in research among groups of workers for evaluating the effectiveness of interventions to prevent adverse occupational heat health effects.

The effect of deforestation and climate change on all-cause mortality and unsafe work conditions due to heat exposure in Berau, Indonesia: a modelling study

BACKGROUND

Previous studies focusing on urban, industrialised regions have found that excess heat exposure can increase all-cause mortality, heat-related illnesses, and occupational injuries. However, little research has examined how deforestation and climate change can adversely affect work conditions and population health in low latitude, industrialising countries.

METHODS

For this modelling study we used data at 1 km² resolution to compare forest cover and temperature conditions in the Berau regency, Indonesia, between 2002 and 2018. We used spatially explicit satellite, climate model, and population data to estimate the effects of global warming, between 2002 and 2018 and after applying 1·0°C, 1·5°C, and 2·0°C of global warming to 2018 temperatures, on all-cause mortality and unsafe work conditions in the Berau regency, Indonesia.

FINDINGS

Between 2002 and 2018, 4375 km² of forested land in Berau was cleared, corresponding to approximately 17% of the entire regency. Deforestation increased mean daily maximum temperatures by 0·95°C (95% CI 0·97-0·92; p<0·0001). Mean daily temperatures increased by a population-weighted 0·86°C, accounting for an estimated 7·3-8·5% of all-cause mortality (or 101-118 additional deaths per year) in 2018. Unsafe work time increased by 0·31 h per day (95% CI 0·30-0·32; p<0·0001) in deforested areas compared to 0·03 h per day (0·03-0·04; p<0·0001) in areas that maintained forest cover. With 2·0°C of additional future global warming, relative to 2018, deforested areas could experience an estimated 17-20% increase in all-cause mortality (corresponding to an additional 236-282 deaths per year) and up to 5 h of unsafe work per day.

INTERPRETATION

Heat exposure from deforestation and climate change has already started affecting populations in low latitude, industrialising countries, and future global warming indicates substantial health impacts in these regions. Further research should examine how deforestation is currently affecting the health and wellbeing of local communities.

FUNDING

University of Washington Population Health Initiative.

TRANSLATION

For the Bahasa translation of the abstract see Supplementary Materials section.

Heat illness data strengthens vulnerability maps

Background

Previous extreme heat and human health studies have investigated associations either over time (e.g. case-crossover or time series analysis) or across geographic areas (e.g. spatial models), which may limit the study scope and regional variation. Our study combines a case-crossover design and spatial analysis to identify: 1) the most vulnerable counties to extreme heat; and 2) demographic and socioeconomic variables that are most strongly and consistently related to heat-sensitive health outcomes (cardiovascular disease, dehydration, heat-related illness, acute renal disease, and respiratory disease) across 67 counties in the state of Florida, U. S over 2008–2012.

Methods

We first used a case-crossover design to examine the effects of air temperature on daily counts of health outcomes. We employed a time-stratified design with a 28-day comparison window. Referent periods were extracted from ±7, ±14, or ± 21 days to address seasonality. The results are expressed as odds ratios, or the change in the likelihood of each health outcome for a unit change in heat exposure. We then spatially examined the case-crossover extreme heat and health odds ratios and county level demographic and socioeconomic variables with multiple linear regression or spatial lag models.

Results

Results indicated that southwest Florida has the highest risks of cardiovascular disease, dehydration, acute renal disease, and respiratory disease. Results also suggested demographic and socioeconomic variables were significantly associated with the magnitude of heat-related health risk. The counties with larger populations working in farming, fishing, mining, forestry, construction, and extraction tended to have higher risks of dehydration and acute renal disease, whereas counties with larger populations working in installation, maintenance, and repair workers tended to have lower risks of cardiovascular, dehydration, acute renal disease, and respiratory disease. Finally, our results showed that high income counties consistently have lower health risks of dehydration, heat-related illness, acute renal disease, and respiratory disease.

Conclusions

Our study identified different relationships with demographic/socioeconomic variables for each heat-sensitive health outcome. Results should be incorporated into vulnerability or risk indices for each health outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12097-6.

Using social security number to identify sub-populations vulnerable to the health impacts from extreme heat in Florida, U.S

BACKGROUND

Some socioeconomically vulnerable groups may experience disproportionately higher risk of extreme heat illness than other groups, but no study has utilized the presence/absence of a social security number (SSN) as a proxy for vulnerable sub-populations.

METHODS

This study focused on the warm season from 2008 to 2012 in Florida, U.S. With a total number of 8,256,171 individual level health outcomes, we devised separate case-crossover models for five heat-sensitive health outcomes (cardiovascular disease, dehydration, heat-related illness, renal disease, and respiratory disease), type of health care visit (emergency department (ED) and hospitalization), and patients reporting/not reporting an SSN. Each stratified model also considered potential effect modification by sex, age, or race/ethnicity.

RESULTS

Mean temperature raised the odds of five heat-sensitive health outcomes with the highest odds ratios (ORs) for heat-related illness. Sex significantly modified heat exposure effects for dehydration ED visits (Males: 1.145, 95 % CI: 1.137-1.153; Females: 1.110, 95 % CI: 1.103-1.117) and hospitalization (Males: 1.116, 95 % CI: 1.110-1.121; Females: 1.100, 95 % CI: 1.095-1.105). Patients not reporting an SSN between 25 and 44 years (1.264, 95 % CI: 1.192-1.340) exhibited significantly higher dehydration ED ORs than those reporting an SSN (1.146, 95 % CI: 1.136-1.157). We also observed significantly higher ORs for cardiovascular disease hospitalization from the no SSN group (SSN: 1.089, 95 % CI: 1.088-1.090; no SSN: 1.100, 95 % CI: 1.091-1.110).

CONCLUSIONS

This paper partially supports the idea that individuals without an SSN could experience higher risks of dehydration (for those 25-45 years), renal disease, and cardiovascular disease than those with an SSN.

Heat Safety in the Workplace: Modified Delphi Consensus to Establish Strategies and Resources to Protect the US Workers

The purpose of this consensus document was to develop feasible, evidence-based occupational heat safety recommendations to protect the US workers that experience heat stress. Heat safety recommendations were created to protect worker health and to avoid productivity losses associated with occupational heat stress. Recommendations were tailored to be utilized by safety managers, industrial hygienists, and the employers who bear responsibility for implementing heat safety plans. An interdisciplinary roundtable comprised of 51 experts was assembled to create a narrative review summarizing current data and gaps in knowledge within eight heat safety topics: (a) heat hygiene, (b) hydration, (c) heat acclimatization, (d) environmental monitoring, (e) physiological monitoring, (f) body cooling, (g) textiles and personal protective gear, and (h) emergency action plan implementation. The consensus-based recommendations for each topic were created using the Delphi method and evaluated based on scientific evidence, feasibility, and clarity. The current document presents 40 occupational heat safety recommendations across all eight topics. Establishing these recommendations will help organizations and employers create effective heat safety plans for their workplaces, address factors that limit the implementation of heat safety best-practices and protect worker health and productivity.

The multi-level heat education and awareness tools [HEAT] intervention study for farmworkers: Rationale and methods

Background

The burden of adverse health effects from heat exposure is substantial, and outdoor workers who perform heavy physical work are at high risk. Though heat prevention interventions have been developed, studies have not yet systematically evaluated the effectiveness of approaches that address risk factors at multiple levels.

Objective

We sought to test the effectiveness of a multi-level heat prevention approach (heat education and awareness tools [HEAT]), which includes participatory training for outdoor agricultural workers that addresses individual and community factors and a heat awareness mobile application for agricultural supervisors that supports decisions about workplace heat prevention, in the Northwest United States.

Design

We designed the HEAT study as a parallel, comparison, randomized group intervention study that recruited workers and supervisors from agricultural workplaces. In intervention arm crews, workers received HEAT training, and supervisors received the HEAT awareness application. In comparison arm crews, workers were offered non-HEAT training. Primary outcomes were worker physiological heat strain and heat-related illness (HRI) symptoms. In both worker groups, we assessed HRI symptoms approximately weekly, and heat strain physiological monitoring was conducted at worksites approximately monthly, from June through August.

Discussion

To our knowledge, this is the first study to evaluate the effectiveness of a multi-level heat prevention intervention on physiological heat strain and HRI symptoms for outdoor agricultural workers.

Trial registration

ClinicalTrials.gov Registration Number: NCT04234802;

Warming from tropical deforestation reduces worker productivity in rural communities

The accelerating loss of tropical forests in the 21st century has eliminated cooling services provided by trees in low latitude countries. Cooling services can protect rural communities and outdoor workers with little adaptive capacity from adverse heat exposure, which is expected to increase with climate change. Yet little is still known about whether cooling services can mitigate negative impacts of heat on labor productivity among rural outdoor workers. Through a field experiment in Indonesia, we show that worker productivity was 8.22% lower in deforested relative to forested settings, where wet bulb globe temperatures were, on average, 2.84 °C higher in deforested settings. We demonstrate that productivity losses are driven by behavioral adaptations in the form of increased number of work breaks, and provide evidence that suggests breaks are in part driven by awareness of heat effects on work. Our results indicate that the cooling services from forests have the potential for increasing resilience and adaptive capacity to local warming.

It is expected that tropical deforestation and related increases in heat exposure have negative impacts on labour productivity, but the size of the effect is not well known. Here, the authors show that deforestation reduces productivity by 8.22% in rural Indonesia and causes behavioural adaptation responses like more work breaks.

Preliminary comparison of vibration measurement accuracy between a low cost, portable acceleration measurement unit and a gold-standard accelerometer system

Characterization of Whole-Body Vibration (WBV) exposure is important for the development and evaluation of mitigation strategies for occupational WBV. However, barriers associated with cost and complexity limit widespread use of current gold-standard accelerometer (GSA) measurement systems. Small, simple, low cost Acceleration Measurement Unit (AMU) devices with built-in batteries and memory potentially allow for more efficient collection of WBV data, but the measurement accuracy of these devices need to be evaluated. Using known acceleration inputs generated by an accelerometer calibrator and field collected vibration profiles simulating real-world vibration exposures, the measurements of an AMU device and GSA system were compared. Analysis of accelerometer calibrator data showed no significant difference in weighted acceleration (A_w) measurements between the systems (mean difference -0.001 m/s², p = 0.95). In field collected vibration profile testing, differences in A_w measurements were small (0.06 m/s², 4.6%). These results suggest the AMU evaluated in this study may be acceptable for measuring occupational WBV.

Work Adaptations Insufficient to Address Growing Heat Risk for U.S. Agricultural Workers

The over one million agricultural workers in the United States (U.S.) are amongst the populations most vulnerable to the health impacts of extreme heat. Climate change will further increase this vulnerability. Here we estimate the magnitude and spatial patterns of the growing heat exposure and health risk faced by U.S. crop workers and assess the effect of workplace adaptations on mitigating that risk. We find that the average number of days spent working in unsafe conditions will double by mid-century, and, without mitigation, triple by the end of it. Increases in rest time and the availability of climate-controlled recovery areas can eliminate this risk but could affect farm productivity, farm worker earnings, and/or labor costs much more than alternative measures. Safeguarding the health and well-being of U.S. crop workers will therefore require systemic change beyond the worker and workplace level.

Heat Exposure and Occupational Injuries: Review of the Literature and Implications

PURPOSE OF REVIEW

The burden of heat-related adverse occupational health effects, as well as traumatic injuries, is already substantial. Projected increases in mean temperatures and extreme events may increase the risk of adverse heat health effects and enhance disparities among exposed workers. This article reviews the emerging literature on the relationship between heat exposure and occupational traumatic injuries and discusses implications of this work.

RECENT FINDINGS

A recent meta-analysis of three case-crossover and five time series studies in industrialized settings reported an association of increasing occupational injuries with increasing heat exposure, with increased effect estimates for male gender and age less than 25 years, although heterogeneity in exposure metrics and sources of bias were demonstrated to varying degrees across studies. A subsequent case-crossover study in outdoor construction workers reported a 0.5% increase in the odds of traumatic injuries per 1 °C increase in maximum daily humidex (odds ratio 1.005 [95% CI 1.003-1.007]). While some studies have demonstrated reversed U-shaped associations between heat exposure and occupational injuries, different risk profiles have been reported in different industries and settings. Studies conducted primarily in industrialized settings suggest an increased risk of traumatic injury with increasing heat exposure, though the exact mechanisms of heat exposure's effects on traumatic injuries are still under investigation. The effectiveness of heat-related injury prevention approaches has not yet been established. To enhance the effectiveness of prevention efforts, prioritization of approaches should take into account not only the hierarchy of controls, social-ecological models, community and stakeholder participation, and tailoring of approaches to specific local work settings, but also methods that reduce local and global disparities and better address the source of heat exposure, including conservation-informed land-use planning, built environment, and prevention through design approaches. Participation of occupational health experts in transdisciplinary development and integration of these approaches is needed.

Association between work in deforested, compared to forested, areas and human heat strain: An experimental study in a rural tropical environment

BACKGROUND

With climate change, adverse human health effects caused by heat exposure are of increasing public health concern. Forests provide beneficial ecosystem services for human health, including local cooling. Few studies have assessed the relationship between deforestation and heat-related health effects in tropical, rural populations. We sought to determine whether deforested compared to forested landscapes are associated with increased physiological heat strain in a rural, tropical environment.

METHODS

We analyzed data from 363 healthy adult participants from ten villages who participated in a two-by-two factorial, randomized study in East Kalimantan, Indonesia from 10/1/17 to 11/6/17. Using simple randomization, field staff allocated participants equally to different conditions to conduct a 90-minute outdoor activity, representative of typical work. Core body temperature was estimated at each minute during the activity using a validated algorithm from baseline oral temperatures and sequential heart rate data, measured using chest band monitors. We used linear regression models, clustered by village and with a sandwich variance estimator, to assess the association between deforested versus forested conditions and the number of minutes each participant spent above an estimated core body temperature threshold of 38.5°C.

RESULTS

Compared to those in the forested condition (n=172), participants in the deforested condition (n=159) spent an average of 3.08 (95% CI 0.57, 5.60) additional minutes with an estimated core body temperature exceeding 38.5°C, after adjustment for age, sex, body mass index, and experiment start time, with a larger difference among those who began the experiment after 12 noon (5.17 [95% CI 2.20, 8.15]).

CONCLUSIONS

In this experimental study in a tropical, rural setting, activity in a deforested versus a forested setting was associated with increased objectively measured heat strain. Longer durations of hyperthermia can increase the risk of serious health outcomes. Land use decisions should consider the implications of deforestation on local heat exposure and health as well as on forest services, including carbon storage functions that impact climate change mitigation.

Associations between heat exposure, vigilance, and balance performance in summer tree fruit harvesters

BACKGROUND

We sought to evaluate potential mediators of the relationship between heat exposure and traumatic injuries in outdoor agricultural workers.

METHODS

Linear mixed models were used to estimate associations between maximum work-shift Wet Bulb Globe Temperature (WBGT_max) and post-shift vigilance (reaction time) and postural sway (total path length) in a cross-sectional sample of 46 Washington State tree fruit harvesters in August-September 2015.

RESULTS

The mean (SD) WBGT_max was 27.4 (3.2)°C in August and 21.2 (2.0)°C in September. The mean pre-work-shift participant urine specific gravity indicated minimal dehydration. Twenty-four percent of participants exhibited possible excessive sleepiness. There was no association between WBGT_max and post-shift reaction time or total path length.

CONCLUSIONS

Heat exposure was not associated with impaired vigilance or balance in this study, in which the overall mean (SD) WBGT_max was 25.9 (4.2)°C. However, the study identified opportunities to ensure adequate pre-work-shift hydration and to optimize sleep and work-shift timing in order to reduce occupational injury and heat-related illness risk.

Heat exposure and productivity in orchards: Implications for climate change research

Recent studies suggest that heat exposure degrades work productivity, but such studies have not considered individual- and workplace-level factors. Forty-six tree-fruit harvesters (98% Latino/a) from 6 orchards participated in a cross-sectional study in central/eastern Washington in 2015. The association between maximum measured work-shift wet-bulb globe temperature (WBGT_max) and productivity (total weight of fruit bins collected per time worked) was estimated using linear mixed-effects models, adjusting for relevant confounders. The mean (standard deviation) WBGT_max was 27.9°C (3.6°C) in August and 21.2°C (2.0°C) in September. There was a trend of decreasing productivity with increasing WBGT_max, but this association was not statistically significant. When individual- and workplace-level factors were included in the model, the association approached the null. Not considering individual, work, and economic factors that affect rest and recovery in projections of the effects of climate change could result in overestimates of reductions in future productivity and underestimate risk of heat illness.

Hydration and Cooling Practices Among Farmworkers in Oregon and Washington

OBJECTIVES

Although recommendations for preventing occupational heat-related illness among farmworkers include hydration and cooling practices, the extent to which these recommendations are universally practiced is unknown. The objective of this analysis was to compare hydration and cooling practices between farmworkers in Oregon and Washington.

METHODS

A survey was administered to a purposive sample of Oregon and Washington farmworkers. Data collected included demographics, work history and current work practices, hydration practices, access and use of cooling measures, and headwear and clothing worn.

RESULTS

Oregon farmworkers were more likely than those in Washington to consume beverages containing sugar and/or caffeine. Workers in Oregon more frequently reported using various cooling measures compared with workers in Washington. Availability of cooling measures also varied between the two states.

CONCLUSIONS

These results highlight the large variability between workers in two states regarding access to and use of methods to stay cool while working in the heat.

Opportunities and Challenges for Personal Heat Exposure Research

BACKGROUND

Environmental heat exposure is a public health concern. The impacts of environmental heat on mortality and morbidity at the population scale are well documented, but little is known about specific exposures that individuals experience.

OBJECTIVES

The first objective of this work was to catalyze discussion of the role of personal heat exposure information in research and risk assessment. The second objective was to provide guidance regarding the operationalization of personal heat exposure research methods.

DISCUSSION

We define personal heat exposure as realized contact between a person and an indoor or outdoor environment that poses a risk of increases in body core temperature and/or perceived discomfort. Personal heat exposure can be measured directly with wearable monitors or estimated indirectly through the combination of time-activity and meteorological data sets. Complementary information to understand individual-scale drivers of behavior, susceptibility, and health and comfort outcomes can be collected from additional monitors, surveys, interviews, ethnographic approaches, and additional social and health data sets. Personal exposure research can help reveal the extent of exposure misclassification that occurs when individual exposure to heat is estimated using ambient temperature measured at fixed sites and can provide insights for epidemiological risk assessment concerning extreme heat.

CONCLUSIONS

Personal heat exposure research provides more valid and precise insights into how often people encounter heat conditions and when, where, to whom, and why these encounters occur. Published literature on personal heat exposure is limited to date, but existing studies point to opportunities to inform public health practice regarding extreme heat, particularly where fine-scale precision is needed to reduce health consequences of heat exposure. https://doi.org/10.1289/EHP556.

Promoting Early, Safe Return to Work in Injured Employees: A Randomized Trial of a Supervisor Training Intervention in a Healthcare Setting

Purpose Supervisors in the healthcare sector have the potential to contribute to disability prevention in injured employees. Published data on the evaluation of return to work (RTW) interventions aimed at direct supervisors are scarce. We sought to determine the effect of a brief audiovisual supervisor training module on supervisor RTW attitudes and knowledge. Methods A parallel-group study, using equal randomization, comparing the training module intervention to usual practice in healthcare supervisors at a quaternary care hospital was conducted. Differences between groups in changes in RTW attitude and knowledge survey question scores between baseline and 3 months were assessed using the Mann-Whitney U test. The Benjamini-Hochberg-Yekutieli procedure was used to control for false discovery rate and generate adjusted p values. Results Forty supervisors were allocated to the intervention group and 41 to the usual practice group. Attitude and knowledge scores for most questions improved between baseline and immediately after intervention administration. Comparing intervention (n = 33) and usual practice groups (n = 37), there was a trend toward greater increase between baseline and 3 months follow-up in agreement that the supervisor can manage the RTW process (U = 515, adjusted p value = 0.074) and in confidence that the supervisor can answer employees' questions (U = 514, adjusted p value = 0.074) in the intervention group, although these findings were not statistically significant. Conclusions The training intervention may have provided the initial tools for supervisors to navigate the RTW process in collaboration with others in the RTW community of practice. A larger study with longer follow-up is needed to confirm results.

Risk Factors for Heat-Related Illness in Washington Crop Workers

Crop workers are at high risk of heat-related illness (HRI) from internal heat generated by heavy physical work, particularly when laboring in hot and humid conditions. The aim of this study was to identify risk factors for HRI symptoms in Washington crop workers using an audio computer-assisted self-interview (A-CASI) instrument that has undergone reliability and validity evaluation. A cross-sectional A-CASI survey of 97 crop workers in Washington State was conducted during the summer of 2013. Potential HRI risk factors in demographic, training, work, hydration, clothing, health, and environmental domains were selected a priori for evaluation. Mixed-effects logistic regression was used to identify risk factors for self-reported symptoms associated with heat strain and HRI (dizziness/light-headedness or heavy sweating) experienced at work in hot conditions. An increase in age was associated with a lower odds of HRI symptoms (odds ratio [OR] = 0.92; 95% confidence interval [CI] = 0.87-0.98). Piece rate compared with hourly payment (OR = 6.20; 95% CI = 1.11-34.54) and needing to walk for more than 3 minutes to get to the toilet, compared with less than 3 minutes (OR = 4.86; 95% CI = 1.18-20.06), were associated with a higher odds of HRI symptoms. In this descriptive study of risk factors for HRI symptoms in Washington crop workers, decreased age (and less work experience), piece rate pay, and longer distance to the toilet were associated with self-reported HRI symptoms. Modifiable workplace factors should be considered in HRI prevention efforts that are evaluated using objective measures in representative working populations.

Re-evaluating occupational heat stress in a changing climate

The potential consequences of occupational heat stress in a changing climate on workers, workplaces, and global economies are substantial. Occupational heat stress risk is projected to become particularly high in middle- and low-income tropical and subtropical regions, where optimal controls may not be readily available. This commentary presents occupational heat stress in the context of climate change, reviews its impacts, and reflects on implications for heat stress assessment and control. Future efforts should address limitations of existing heat stress assessment methods and generate economical, practical, and universal approaches that can incorporate data of varying levels of detail, depending on resources. Validation of these methods should be performed in a wider variety of environments, and data should be collected and analyzed centrally for both local and large-scale hazard assessments and to guide heat stress adaptation planning. Heat stress standards should take into account variability in worker acclimatization, other vulnerabilities, and workplace resources. The effectiveness of controls that are feasible and acceptable should be evaluated. Exposure scientists are needed, in collaboration with experts in other areas, to effectively prevent and control occupational heat stress in a changing climate.

Biographic and behavioral factors are associated with music-related motor skills in children pianists

This study aimed to identify biographical and behavioral factors associated with children pianists' motor skills using an objective assessment of a music-relevant motor task. Motor skills at the piano were assessed in 30 children pianists by measuring temporal unevenness in standardized scale playing using musical instrument digital interface (MIDI)-based scale analysis. Questionnaires were used to collect detailed information about the amount of time playing the piano, practice characteristics, attitudes toward music and practice, and the environment of music and practice. Associations between performance values and variables from the questionnaire were investigated using multivariable linear regression. A higher number of years playing the piano, more frequent parental involvement in the child's practice, more frequent practice of technical exercises, and greater enjoyment of practice and of the visual arts were associated with better motor performance. In addition to cumulative experience and aspects of practice, extrinsic motivational factors (e.g., parental interest) and intrinsic motivational factors (e.g., an artistic disposition) were associated with better performance on a musically-relevant motor task in children pianists.

Heat-related illness in Washington State agriculture and forestry sectors

BACKGROUND

We sought to describe heat-related illness (HRI) in agriculture and forestry workers in Washington State.

METHODS

Demographic and clinical Washington State Fund workers' compensation agriculture and forestry HRI claims data (1995-2009) and Washington Agriculture Heat Rule citations (2009-2012) were accessed and described. Maximum daily temperature (Tmax) and Heat Index (HImax) were estimated by claim date and location using AgWeatherNet's weather station network.

RESULTS

There were 84 Washington State Fund agriculture and forestry HRI claims and 60 Heat Rule citations during the study period. HRI claims and citations were most common in crop production and support subsectors. The mean Tmax (HImax) was 95°F (99°F) for outdoor HRI claims. Potential HRI risk factors and HRI-related injuries were documented for some claims.

CONCLUSIONS

Agriculture and forestry HRI cases are characterized by potential work-related, environmental, and personal risk factors. Further work is needed to elucidate the relationship between heat exposure and occupational injuries.

Automation of workplace lifting hazard assessment for musculoskeletal injury prevention

Objectives

Existing methods for practically evaluating musculoskeletal exposures such as posture and repetition in workplace settings have limitations. We aimed to automate the estimation of parameters in the revised United States National Institute for Occupational Safety and Health (NIOSH) lifting equation, a standard manual observational tool used to evaluate back injury risk related to lifting in workplace settings, using depth camera (Microsoft Kinect) and skeleton algorithm technology.

Methods

A large dataset (approximately 22,000 frames, derived from six subjects) of simultaneous lifting and other motions recorded in a laboratory setting using the Kinect (Microsoft Corporation, Redmond, Washington, United States) and a standard optical motion capture system (Qualysis, Qualysis Motion Capture Systems, Qualysis AB, Sweden) was assembled. Error-correction regression models were developed to improve the accuracy of NIOSH lifting equation parameters estimated from the Kinect skeleton. Kinect-Qualysis errors were modelled using gradient boosted regression trees with a Huber loss function. Models were trained on data from all but one subject and tested on the excluded subject. Finally, models were tested on three lifting trials performed by subjects not involved in the generation of the model-building dataset.

Results

Error-correction appears to produce estimates for NIOSH lifting equation parameters that are more accurate than those derived from the Microsoft Kinect algorithm alone. Our error-correction models substantially decreased the variance of parameter errors. In general, the Kinect underestimated parameters, and modelling reduced this bias, particularly for more biased estimates. Use of the raw Kinect skeleton model tended to result in falsely high safe recommended weight limits of loads, whereas error-corrected models gave more conservative, protective estimates.

Conclusions

Our results suggest that it may be possible to produce reasonable estimates of posture and temporal elements of tasks such as task frequency in an automated fashion, although these findings should be confirmed in a larger study. Further work is needed to incorporate force assessments and address workplace feasibility challenges. We anticipate that this approach could ultimately be used to perform large-scale musculoskeletal exposure assessment not only for research but also to provide real-time feedback to workers and employers during work method improvement activities and employee training.

Plasma polychlorinated biphenyl concentrations and immune function in postmenopausal women

BACKGROUND

Polychlorinated biphenyl (PCB) exposure has been associated with non-Hodgkin lymphoma in several studies, and the immune system is a potential mediator.

OBJECTIVES

We analyzed associations of plasma PCBs with immune function measures. We hypothesized that higher plasma PCB concentrations are associated with lower immune function cross-sectionally, and that increases in PCB concentrations over a one year period are associated with decreases in immune function.

METHODS

Plasma PCB concentrations and immune function [natural killer (NK) cell cytotoxicity and PHA-induced T-lymphocyte proliferation (PHA-TLP)] were measured at baseline and one year in 109 postmenopausal overweight women participating in an exercise intervention study in the Seattle, Washington (USA) area. Mixed models, with adjustment for body mass index and other potential confounders, were used to estimate associations of PCBs with immune function cross-sectionally and longitudinally.

RESULTS

Associations of PCBs with immune function measures differed across groups of PCBs (e.g., medium- and high-chlorinated and dioxin-like [mono-ortho-substituted]) and by the time frame for the comparison (cross-sectional vs. longitudinal). Higher concentrations of medium- and high-chlorinated PCBs were associated with higher PHA-TLP cross-sectionally but not longitudinally. The mean decrease in 0.5 µg/mL PHA-TLP/50.0 pmol/g-lipid increase in dioxin-like PCBs over one year was 51.6 (95% confidence interval 2.7, 100.5; P=0.039). There was no association between plasma PCBs and NK cytotoxicity.

CONCLUSIONS

These results do not provide strong evidence of impaired cellular immunity from PCB exposure. Larger longitudinal studies with greater variability in PCB exposures are needed to further examine temporal associations of PCBs with immune function.

Identification of barriers to the prevention and treatment of heat-related illness in Latino farmworkers using activity-oriented, participatory rural appraisal focus group methods

BACKGROUND

Heat-related illness (HRI) is an important cause of non-fatal illness and death in farmworkers. We sought to identify potential barriers to HRI prevention and treatment in Latino farmworkers.

METHODS

We conducted three semi-structured focus group discussions with 35 Latino farmworkers in the Central Washington, USA area using participatory rural appraisal techniques. Interviews were audio taped and transcribed in Spanish. Three researchers reviewed and coded transcripts and field notes, and investigator triangulation was used to identify relevant themes and quotes.

RESULTS

Although the majority of participants in our study reported never receiving formal HRI training, most participants were aware that extreme heat can cause illness and were able to accurately describe HRI symptoms, risk factors, and certain prevention strategies. Four main observations regarding farmworkers' HRI-relevant beliefs and attitudes were identified: 1) farmworkers subscribe to varying degrees to the belief that cooling treatments should be avoided after heat exposure, with some believing that such treatments should be avoided after heat exposure, and others encouraging the use of such treatments; 2) the desire to lose weight may be reflected in behaviors that promote increased sweating; 3) highly caffeinated energy drinks are preferred to increase work efficiency and maintain alertness; and 4) the location of drinking water at work (e.g. next to restrooms) and whether water is clean, but not necessarily chemically-treated, are important considerations in deciding whether to drink the water provided at worksites.

CONCLUSIONS

We identified potential barriers to HRI prevention and treatment related to hydration, certain HRI treatments, clothing use, and the desire to lose weight among Latino farmworkers. Strategies to address potential barriers to HRI prevention and treatment in this population may include engineering, administrative, and health education and health promotion strategies at individual, workplace, community, and societal levels. Although farmworkers in our study were able to describe HRI risk factors, reported practices were not necessarily consistent with reported knowledge. Further study of potential knowledge-behavior gaps may uncover opportunities for additional HRI prevention strategies. Farmworkers and employers should be included in the development and evaluation of interventions to prevent HRI.

Distribution of influenza-like illness (ILI) by occupation in Washington State, September 2009-August 2010

OBJECTIVES

We aim to estimate the prevalence of influenza-like illness (ILI) by occupation and to identify occupations associated with increased ILI prevalence.

METHODS

Between September 2009 and August 2010, the Centers for Disease Control (CDC) included questions on ILI symptoms on the Behavioral Risk Factor Surveillance System (BRFSS). Washington State collects the occupation of all employed BRFSS respondents. ILI prevalence and prevalence ratios (PR) were calculated by occupational group.

RESULTS

There were 8,758 adult, currently employed, non-military respondents to the Washington BRFSS during the study period. The ILI prevalence for all employed respondents was 6.8% (95% Confidence Interval (95% CI) = 6.1, 7.6). PRs indicated a lower prevalence of ILI in Technicians (PR = 0.4, 95% CI = 0.2, 0.9) and Truck Drivers (PR = 0.2, 95% CI = 0.1, 0.7) and higher prevalence in Janitors and Cleaners (PR = 2.5, 95% CI = 1.3, 4.7) and Secretaries (PR = 2.4, 95% CI = 1.1, 5.4).

CONCLUSIONS

Some occupations appear to have higher prevalence of ILI than others. These occupational differences may be explained, in part, by differing levels of social contact with the public or contact with contaminated surfaces at work, or by other occupational factors such as stress or access to health care resources.

Pre-surgery disability compensation predicts long-term disability among workers with carpal tunnel syndrome

BACKGROUND

We sought to identify early risk factors for work disability compensation prior to and after carpal tunnel syndrome (CTS) surgery, and to determine whether pre-surgery disability compensation is associated with long-term disability.

METHODS

Washington State workers' compensation administrative data and data from interviews with workers 18 days (median) after submitting new workers' compensation claims for CTS were examined. Baseline risk factors for pre-surgery disability compensation and for long-term disability (>365 days of work disability compensation prior to 2 years after claim filing) were evaluated for workers who underwent CTS surgery and had at least 1 day of disability compensation (N = 670).

RESULTS

After adjustment for baseline long-term disability risk factors, workers with pre-surgery disability compensation had over five times the odds of long-term disability. Baseline factors in multiple domains, including job, psychosocial, clinical, and worker pain and function, were associated with both pre-surgery disability compensation and long-term disability.

CONCLUSIONS

Risk factors for work disability prior to and after CTS surgery are similar, and early work disability is a risk factor for long-term CTS-related disability. An integrated approach to CTS-related disability prevention could include identifying and addressing combined risk factors soon after claim filing, more efficient use of conservative treatments and appropriate work modifications to minimize early work loss, and, when indicated, timely surgical intervention.

Musician's dystonia and comorbid anxiety: two sides of one coin?

BACKGROUND

Psychological abnormalities, including anxiety, have been observed in patients with musician's dystonia (MD). It is unclear if these conditions develop prior to MD or if they are psychoreactive phenomena.

METHODS

Psychological conditions were studied in 44 professional musicians with MD, 45 healthy musicians, and 44 healthy nonmusicians using the State-Trait Anxiety Inventory (STAI) and NEO Five-Factor Inventory (NEO-FFI).

RESULTS

Musicians with MD had significantly higher STAI state and trait anxiety scores than healthy musicians (P = .009 and P = .012, respectively) and nonmusicians (P = .013 and P = .001, respectively) and significantly higher NEO-FFI neuroticism scores than healthy musicians (P = .018) and nonmusicians (P = .001). Duration of dystonia did not correlate with anxiety or neuroticism scores.

CONCLUSIONS

Musicians with MD display increased levels of anxiety and neuroticism. The lack of correlation between anxiety and the duration of dystonia suggests that anxiety may not be a psychoreactive phenomenon and is consistent with the hypothesis that anxiety and MD share a common pathophysiological mechanism.

Associations of blood lead with estimated glomerular filtration rate using MDRD, CKD-EPI and serum cystatin C-based equations

BACKGROUND

Low-level lead exposure is widespread and has been implicated as a chronic kidney disease (CKD) risk factor. However, studies evaluating associations of lead dose with newer, potentially more accurate, estimates of kidney function, in participants with a wide range of glomerular filtration rates (GFRs), are scarce.

METHODS

We compared associations of blood lead and estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and cystatin C single variable, multivariable and combined creatinine/cystatin C equations in 3941 adults who participated in the 1999-2002 National Health and Nutrition Examination Survey cystatin C subsample.

RESULTS

Geometric mean blood lead was 1.7 μg/dL. After multivariable adjustment, differences [95% confidence interval (CI)] in mean eGFR for a doubling of blood lead were -1.9 (-3.2, -0.7), -1.7 (-3.0, -0.5) and -1.4 (-2.3, -0.5) mL/min/1.73 m(2), using the cystatin C single variable, multivariable and combined creatinine/cystatin C equations, respectively, reflecting lower eGFR with increased blood lead. The corresponding differences (95% CI) were -0.9 (-1.9, 0.02) and -0.9 (-1.8, 0.01) using the creatinine-based MDRD and CKD-EPI equations, respectively. In participants aged ≥60 years, differences in mean eGFR ranged from -3.0 to -4.5 mL/min/1.73 m(2), and odds of reduced eGFR (<60 mL/min/1.73 m(2)) were increased for all estimates of GFR.

CONCLUSIONS

These results support the inclusion of cystatin C-based eGFR in future lead research and provide additional evidence for environmental lead exposure as a CKD risk factor.

Methods of evaluation of musician's dystonia: critique of measurement tools

Musician's dystonia is associated with significant morbidity. To assess treatment options, accurate and precise measurements of disease severity are critical. We describe current methods of quantitatively measuring musician's dystonia of the upper extremity including subjective, objective, and automated methods. The degree to which these methods satisfy rigorous measurement criteria, including their reliability, validity, responsiveness to treatment, and practicality, is examined. We report that most of these methods have not been properly evaluated. Therefore, treatment trials based on these methods are difficult to interpret.