Are Cal/OSHA Regulations Protecting Farmworkers in California From Heat-Related Illness?

Summarizing Recommendations for the Prevention of Occupational Heat-Related Illness in Outdoor Workers: A Scoping Review

BACKGROUND

Outdoor workers face unique challenges in preventing heat-related illnesses (HRI). Although preventable, HRI and death from heat exposure continue. A review of the most recent recommendation for HRI prevention in outdoor workers in the United States was warranted. A scoping review using PRISMA guidelines was conducted to compile policy statements and recommendations on the prevention of HRI and synthesize them into a three-step plan for prevention using the Haddon Matrix.

METHOD

PubMed, CINAHL, Medline, and websites from organizations and regulating bodies were searched for sources. Key terms such as occupational OR workers OR employers OR policymakers, HRI OR heat stress OR heat, prevention, recommendations OR position statements were used. Inclusion criteria were articles published within the last 5 years written in English and containing recommendations for preventing HRI in outdoor workers. Research not based on U.S. workers was excluded from the review.

RESULTS

Twenty sources comprised the review. Several themes emerged, indicating deficient recommendations for secondary and tertiary prevention.

CONCLUSION/APPLICATION TO PRACTICE

This review's findings can be used by occupational health nurses (OHNs) in developing comprehensive interventions for preventing HRI and injury, using clear language, and following evidenced-based practices to increase workplace health and safety and promote equity.

Severity Analysis for Occupational Heat-related Injury Using the Multinomial Logit Model

Background

Workers are often exposed to hazardous heat due to their work environment, leading to various injuries. As a result of climate change, heat-related injuries (HRIs) are becoming more problematic. This study aims to identify critical contributing factors to the severity of occupational HRIs.

Methods

This study analyzed historical injury reports from the Occupational Safety and Health Administration (OSHA). Contributing factors to the severity of HRIs were identified using text mining and model-free machine learning methods. The Multinomial Logit Model (MNL) was applied to explore the relationship between impact factors and the severity of HRIs.

Results

The results indicated a higher risk of fatal HRIs among middle-aged, older, and male workers, particularly in the construction, service, manufacturing, and agriculture industries. In addition, a higher heat index, collapses, heart attacks, and fall accidents increased the severity of HRIs, while symptoms such as dehydration, dizziness, cramps, faintness, and vomiting reduced the likelihood of fatal HRIs.

Conclusions

The severity of HRIs was significantly influenced by factors like workers' age, gender, industry type, heat index , symptoms, and secondary injuries. The findings underscore the need for tailored preventive strategies and training across different worker groups to mitigate HRIs risks.

Extreme Heat and Occupational Health Risks

Climate change poses a significant occupational health hazard. Rising temperatures and more frequent heat waves are expected to cause increasing heat-related morbidity and mortality for workers across the globe. Agricultural, construction, military, firefighting, mining, and manufacturing workers are at particularly high risk for heat-related illness (HRI). Various factors, including ambient temperatures, personal protective equipment, work arrangements, physical exertion, and work with heavy equipment may put workers at higher risk for HRI. While extreme heat will impact workers across the world, workers in low- and middle-income countries will be disproportionately affected. Tracking occupational HRI will be critical to informing prevention and mitigation strategies. Renewed investment in these strategies, including workplace heat prevention programs and regulatory standards for indoor and outdoor workers, will be needed. Additional research is needed to evaluate the effectiveness of interventions in order to successfully reduce the risk of HRI in the workplace.

High temperatures on mental health: Recognizing the association and the need for proactive strategies-A perspective

Background and Aims

The influence of temperature on various aspects of daily life is often underestimated, and its effects on mental health are not widely recognized. Understanding and addressing the relationship between temperature and mental well-being is crucial in the context of climate change and rising global temperatures. This perspective aimed to investigate the effects of high temperatures on mental health and identify proactive strategies to mitigate these effects.

Methods

This perspective adopted a twofold approach, including a comprehensive literature review and socioecological framework. The literature review involved extensive searches across Google Scholar, PubMed, and Scopus to identify relevant, peer-reviewed articles, and reports from diverse disciplines.

Results

The perspective emphasized the significance of recognizing heat stress and its consequences on mental well-being. Chronic heat stress can lead to increased stress, anxiety, and cognitive impairment. Vulnerable populations include, the very young, older adults, and individuals with pre-existing mental health conditions. Socioeconomic factors can further exacerbate vulnerability, highlighting the need for tailored strategies to manage mental health challenges during high temperatures. Additionally, the article identified and discussed proactive coping strategies to minimize both the psychological and physical impacts of heat stress. Mindfulness, stress management techniques, and therapy are suggested as effective means for individuals to manage psychological distress.

Conclusion

Implementing preventive measures are essential steps in promoting mental wellness in high temperatures. Proactive strategies by addressing the physiological and psychological effects of heat and considering the specific needs of vulnerable populations can help individuals and communities navigate the challenges posed by rising temperatures and promote resilience and preserve their mental well-being.

How Does Environmental Temperature Affect Farmworkers' Work Rates in the California Heat Illness Prevention Study?

OBJECTIVE

Estimate the association between environmental temperature (wet bulb globe temperature [WBGT]) and work rate over the course of a workday.

METHODS

Repeated-measures regression was used to identify characteristics impacting work rate in a cross-sectional study of Latino farmworkers. Minute-by-minute work rate (measured by accelerometer) and WBGT were averaged over 15-minute intervals.

RESULTS

Work rate decreased by 4.34 (95% confidence interval [CI], -7.09 to -1.59) counts per minute per degree Celsius WBGT in the previous 15-minute interval. Cumulative quarter hours worked (2.13; 95% CI, 0.82 to 3.45), age (-3.64; 95% CI, -4.50 to -2.79), and dehydration at the end of workday (51.37; 95% CI, 19.24 to 83.50) were associated with counts per minute as were gender, pay type (piece rate vs hourly) and body mass index ≥25 kg/m 2 . The effects of pay type and body mass index were modified by gender.

CONCLUSION

Increased temperature was associated with a decrease in work rate.

Updated assessment of occupational safety and health hazards of climate change

Workers, particularly outdoor workers, are among the populations most disproportionately affected by climate-related hazards. However, scientific research and control actions to comprehensively address these hazards are notably absent. To assess this absence, a seven-category framework was developed in 2009 to characterize the scientific literature published from 1988-2008. Using this framework, a second assessment examined the literature published through 2014, and the current one examines literature from 2014-2021. The objectives were to present literature that updates the framework and related topics and increases awareness of the role of climate change in occupational safety and health. In general, there is substantial literature on worker hazards related to ambient temperatures, biological hazards, and extreme weather but less on air pollution, ultraviolet radiation, industrial transitions, and the built environment. There is growing literature on mental health and health equity issues related to climate change, but much more research is needed. The socioeconomic impacts of climate change also require more research. This study illustrates that workers are experiencing increased morbidity and mortality related to climate change. In all areas of climate-related worker risk, including geoengineering, research is needed on the causality and prevalence of hazards, along with surveillance to identify, and interventions for hazard prevention and control.

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.

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 (PSImax) 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 PSImax, 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 PSImax 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 (HImax), 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 PSImax with high versus low/medium-low effort (main effect 1.96, t = 3.81, p < 0.001) and a lower PSImax with older age (- 0.03, t = - 2.95, p = 0.004), after covariate adjustment. There was no clear relationship between PSImax and the number of HRI symptoms reported. Reporting more symptoms was associated with older age, higher HImax, 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.

Hydration Status in Men Working in Different Thermal Environments: A Pilot Study

The aim of this study was to determine the effects of different seasons of the year and the time of day (before work vs. after work) on hydration status in men. The study involved sixty foresters who spent most of the work outdoors. During three seasons of the year (summer, autumn, and winter), indices of hydration status (body mass (BM) and percentage change of BM, total body water (TBW) and percentage change of TBW, serum osmolality (Sosm) and percentage change of Sosm, urine osmolality, urine-specific gravity (USG), urine color, and thirst) were determined before work on the first day (time point 1 used as baseline), immediately after work on the first day (time point 2), and before work on the following day (time point 3). USG decreased at time point 2 compared to time point 1 (p < 0.001) and time point 3 (p = 0.03). At time point 2 (p = 0.002) in winter and time point 3 in autumn (p = 0.049), serum osmolality was higher than in summer. In conclusion, the differences in hydration status depended on the time of day and season. A large percentage of foresters come to work inadequately hydrated, especially in colder seasons compared to summer.

Extreme Heat and COVID-19: A Dual Burden for Farmworkers

Currently, there is an extensive literature examining heat impacts on labor productivity and health, as well as a recent surge in research around COVID-19. However, to our knowledge, no research to date examines the dual burden of COVID-19 and extreme heat on labor productivity and laborers' health and livelihoods. To close this research gap and shed light on a critical health and livelihood issue affecting a vulnerable population, we urge researchers to study the two topics in tandem. Because farmworkers have a high incidence of COVID-19 infections and a low rate of inoculation, they will be among those who suffer most from this dual burden. In this article, we discuss impacts from extreme heat and COVID-19 on farm laborers. We provide examples from the literature and a conceptual framework showing the bi-directional nature of heat impacts on COVID-19 and vice versa. We conclude with questions for further research and with specific policy recommendations to alleviate this dual burden. If implemented, these policies would enhance the wellbeing of farmworkers through improved unemployment benefits, updated regulations, and consistent implementation of outdoor labor regulations. Additionally, policies for farmworker-related health needs and cultural aspects of policy implementation and farmworker outreach are needed. These and related policies could potentially reduce the dual burden of COVID-19 and extreme heat impacts while future research explores their relative cost-effectiveness.

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 (CBTest) derived from an algorithm that uses sequential heart rate and initializing CBT,1 compared with gastrointestinal temperature measured using more invasive ingestible sensors (CBTgi), among outdoor agricultural workers. We analyzed CBTest and CBTgi 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) CBTgi 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.

Compensation incentives and heat exposure affect farm worker effort

Farm workers are exposed to high risk of heat-related illness, especially when their jobs require working outside at a fast pace during hot days. Climate change has increased the number of days with high temperatures, and thereby the amount of time that farm workers are likely exposed to extreme heat. To better understand how high heat exposure affects farm workers, this study investigates how crop workers respond to heat exposure and estimates the effects of different pay and work arrangements on workers' responses to heat exposure. We explore, specifically, whether piece-rate arrangements increase workers' effort during periods with high heat exposure compared to workers paid by hourly wages. We use observational data from detailed measurements of localized heat exposure and individual workers' effort in the field. First, these results show workers adjust their effort in response to heat exposure when the heat exposure level changes. Second, piece-rate arrangements increase workers' effort during work shifts. Third, piece-rate arrangements allow workers to modify their effort more easily during different heat exposure levels. When facing low levels of heat exposure, workers who were paid by piece-rate arrangements exert a higher effort than workers paid by hourly wages, up until WBGT is 26.6˚C. When facing high levels of heat exposure (with WBGT exceeding 29.6˚C), workers paid by piece-rate arrangements lower their effort compared to workers paid by hourly wage arrangements.

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;