Impact of climate change on occupational health and productivity: a systematic literature review focusing on workplace heat

Impacts of age, type 2 diabetes, and hypertension on circulating neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 after prolonged work in the heat in men

PURPOSE

Prolonged work in the heat increases the risk of acute kidney injury (AKI) in young men. Whether aging and age-associated chronic disease may exacerbate the risk of AKI remains unclear.

METHODS

We evaluated plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum kidney injury molecule-1 (KIM1) before and after 180 min of moderate-intensity work (200 W/m2) in temperate (wet-bulb globe temperature [WBGT] 16 °C) and hot (32 °C) environments in healthy young (n = 13, 22 years) and older men (n = 12, 59 years), and older men with type 2 diabetes (T2D; n = 9, 60 years) or hypertension (HTN; n = 9, 60 years).

RESULTS

There were no changes in NGAL or KIM1 concentrations following prolonged work in temperate conditions in any group. Despite a similar work tolerance, the relative change in NGAL was greater in the older group when compared to the young group following exercise in the hot condition (mean difference + 82 ng/mL; p < 0.001). Baseline concentrations of KIM1 were ~ 22 pg/mL higher in the older relative to young group, increasing by ~ 10 pg/mL in each group after exercise in the heat (both p ≤ 0.03). Despite a reduced work tolerance in the heat in older men with T2D (120 ± 40 min) and HTN (108 ± 42 min), elevations in NGAL and KIM1 were similar to their healthy counterparts.

CONCLUSION

Age may be associated with greater renal stress following prolonged work in the heat. The similar biomarker responses in T2D and HTN compared to healthy older men, alongside reduced exercise tolerance in the heat, suggest these individuals may exhibit greater vulnerability to heat-induced AKI if work is prolonged.

Burning Question: How Does Our Brain Process Positive and Negative Cues Associated with Thermosensation?

Whether it is the dramatic suffocating sensation from a heat wave in the summer or the positive reinforcement arising from a hot drink on a cold day; we can certainly agree that our thermal environment underlies our daily rhythms of sensation. Extensive research has focused on deciphering the central circuits responsible for conveying the impact of thermogenesis on mammalian behavior. Here, we revise the recent literature responsible for defining the behavioral correlates that arise from thermogenic fluctuations in mammals. We transition from the physiological significance of thermosensation to the circuitry responsible for the autonomic or behavioral responses associated with it. Subsequently, we delve into the positive and negative valence encoded by thermoregulatory processes. Importantly, we emphasize the crucial junctures where reward, pain, and thermoregulation intersect, unveiling a complex interplay within these neural circuits. Finally, we briefly outline fundamental questions that are pending to be addressed in the field. Fully deciphering the thermoregulatory circuitry in mammals will have far-reaching medical implications. For instance, it may lead to the identification of novel targets to overcome thermal pain or allow the maintenance of our core temperature in prolonged surgeries.

[Climate change and type I allergies at the workplace]

The consequences of climate change, the increasing frequency, duration and intensity of extreme events such as excessive drought, heat waves, large-scale forest fires, heavy rainfall and associated flooding also affect workers' conditions in the workplace in many ways. Allergic diseases of the respiratory tract and skin due to workplace exposure can also arise or be influenced by direct and indirect consequences of climate change. This affects outdoor workers not only through increased exposure to pollen allergens, but also through climate-related increases in typical workplace allergens. As an indirect effect of climate change, manufacturing processes and exposure at workplaces are changing, which can also cause new sensitization and allergies. Lifestyle changes, which are primarily intended to contribute to climate protection and sustainability, can also lead to new or changed products and thus to changed manufacturing processes and exposures in the workplace, so this should also be considered an indirect effect of climate change on the health of workers. The emergence of new occupational sources of sensitization due to new or changed allergen exposures must be considered in the context of occupational health and safety and requires proactive measures to protect workers.

Development of a Prototype Observatory of Heat-Related Occupational Illnesses and Injuries through the Collection of Information from the Italian Press, as Part of the WORKLIMATE Project

Exposure to heat is a recognized occupational risk factor. Deaths and accidents at work caused by high temperatures are underestimated. With the aim of detecting and monitoring heat-related illnesses and injuries, a prototype database of occupational events attributable to critical thermal conditions reported in Italian newspapers was created. Information was analyzed from national and local online newspapers using a web application. The analysis was conducted from May to September during the three-year period 2020-2022. Articles concerning 35 occupational heat-related illnesses and injuries were selected; 57.1% of the events were reported in 2022, and 31.4% of total accidents occurred in the month of July 2022, when the Universal Thermal Climate Index daily mean values corresponded to "moderate heat stress" (51.0%) and "strong heat stress" (49.0%). Fatal heat-related illnesses were the most frequent conditions described. In most cases, workers had been involved in outdoor activities in the construction sector. A comprehensive report was created by compiling all relevant newspaper articles to enhance awareness of this issue among relevant stakeholders and promote heat-risk prevention strategies in the current context where heatwaves are becoming increasingly frequent, intense and long-lasting.

Effects of Temperatures and Heatwaves on Occupational Injuries in the Agricultural Sector in Italy

The effects of heat on health have been well documented, while less is known about the effects among agricultural workers. Our aim is to estimate the effects and impacts of heat on occupational injuries in the agricultural sector in Italy. Occupational injuries in the agricultural sector from the Italian national workers' compensation authority (INAIL) and daily mean air temperatures from Copernicus ERA5-land for a five-year period (2014-2018) were considered. Distributed lag non-linear models (DLNM) were used to estimate the relative risk and attributable injuries for increases in daily mean air temperatures between the 75th and 99th percentile and during heatwaves. Analyses were stratified by age, professional qualification, and severity of injury. A total of 150,422 agricultural injuries were considered and the overall relative risk of injury for exposure to high temperatures was 1.13 (95% CI: 1.08; 1.18). A higher risk was observed among younger workers (15-34 years) (1.23 95% CI: 1.14; 1.34) and occasional workers (1.25 95% CI: 1.03; 1.52). A total of 2050 heat-attributable injuries were estimated in the study period. Workers engaged in outdoor and labour-intensive activities in the agricultural sector are at greater risk of injury and these results can help target prevention actions for climate change adaptation.

Mortality Risk Related to Heatwaves in Dezful City, Southwest of Iran

BACKGROUND

We aimed to evaluate the impact of heatwaves on daily deaths due to non-accidental, cardiovascular and respiratory causes in the city of Dezful in Iran from 2013 to 2019.

METHOD

We collected daily ambient temperature and mortality and defined 2 types of heatwaves by combining daily temperature ⩾90th in each month of the study period or since 30 years with duration ⩾2 and 3 days. We used a distributed lag non-linear model to study the association between each type of heatwave definition, and deaths due to non-accidental, cardiovascular and respiratory causes with lags up to 13 days.

RESULTS

There was no discernible correlation in this area, despite the fact that heatwaves raised the risk of death from cardiovascular causes and lowered the risk from respiratory causes. On the other hand, the risk of total non-accidental mortality on days with the heatwaves is significantly higher than normal days. In main effects, the heatwaves have a significant relationship with the risk of total non-accidental mortality (in the first heatwave definition, Cumulative Excess Risk (CER) in lag_0-2 was 10.4 and in second heatwave definition, CER values in lag_{0, 0-2, and 0-6} were 12.4, 29.2, and 38.8 respectively). Also, in added effects, heatwaves have a significant relationship with the risk of total non-accidental mortality (in the first heatwave definition, CER in lag_{0 and 0-2} were 1.79 and 4.11 and in the second heatwave definition, CER values in lag_{0, 0-2, and 0-6} were 7.76, 18.35 and 24.87 respectively). In addition, heatwaves appeared to contribute to a cumulative excess risk of non-accidental death among the male group as well as the older adults.

CONCLUSION

However, the results showed that heatwaves could have detrimental effects on health, even in populations accustomed to the extreme heat. Therefore, early warning systems which monitor heatwaves should provide the necessary warnings to the population, especially the most vulnerable groups.

Where do you live and what do you do? Two questions that might impact your kidney health

In many cases the social determinants of health need to be assessed through their interaction with environmental factors. This review looks at the impact of physical location and occupation of individuals on their kidney health. It examines the effect of living at high altitude on kidney function and the relationship between extreme cold or hot temperatures and the incidence of kidney injury. It reviews as well the many occupations that have been linked to kidney disease in high-income and low-and-middle-income countries. As a conclusion, this overview proposes preventive recommendations that could be individualized based on weather, altitude, socio-economic level of the country and occupation of the individual.

Workers’ Perception Heat Stress: Results from a Pilot Study Conducted in Italy during the COVID-19 Pandemic in 2020

Many workers are exposed to the effects of heat and often to extreme temperatures. Heat stress has been further aggravated during the COVID-19 pandemic by the use of personal protective equipment to prevent SARS-CoV-2 infection. However, workers’ risk perception of heat stress is often low, with negative effects on their health and productivity. The study aims to identify workers’ needs and gaps in knowledge, suggesting the adaptation of measures that best comply with the needs of both workers and employers. A cross-sectional online questionnaire survey was conducted in Italy in the hottest months of 2020 (June–October) through different multimedia channels. The data collected were analyzed using descriptive statistics; analytical tests and analysis of variance were used to evaluate differences between groups of workers. In total, 345 questionnaires were collected and analyzed. The whole sample of respondents declared that heat is an important contributor to productivity loss and 83% of workers did not receive heat warnings from their employer. In this context, the internet is considered as the main source of information about heat-related illness in the workplace. Results highlight the need to increase workers’ perception of heat stress in the workplace to safeguard their health and productivity. About two-thirds of the sample stated that working in the sun without access to shaded areas, working indoors without adequate ventilation, and nearby fire, steam, and hot surfaces, represent the main injuries’ risk factors.

Knowledge Gaps and Research Priorities on the Health Effects of Heatwaves: A Systematic Review of Reviews

Although extreme weather events have played a constant role in human history, heatwaves (HWs) have become more frequent and intense in the past decades, causing concern especially in light of the increasing evidence on climate change. Despite the increasing number of reviews suggesting a relationship between heat and health, these reviews focus primarily on mortality, neglecting other important aspects. This systematic review of reviews gathered the available evidence from research syntheses conducted on HWs and health. Following the PRISMA guidelines, 2232 records were retrieved, and 283 reviews were ultimately included. Information was extracted from the papers and categorized by topics. Quantitative data were extracted from meta-analyses and, when not available, evidence was collected from systematic reviews. Overall, 187 reviews were non-systematic, while 96 were systematic, of which 27 performed a meta-analysis. The majority evaluated mortality, morbidity, or vulnerability, while the other topics were scarcely addressed. The following main knowledge gaps were identified: lack of a universally accepted definition of HW; scarce evidence on the HW-mental health relationship; no meta-analyses assessing the risk perception of HWs; scarcity of studies evaluating the efficacy of adaptation strategies and interventions. Future efforts should meet these priorities to provide high-quality evidence to stakeholders.

Fragmentation in the future of work: A horizon scan examining the impact of the changing nature of work on workers experiencing vulnerability

INTRODUCTION

The future of work is characterized by changes that could disrupt all aspects of the nature and availability of work. Our study aims to understand how the future of work could result in conditions, which contribute to vulnerability for different groups of workers.

METHODS

A horizon scan was conducted to systematically identify and synthesize diverse sources of evidence, including academic and gray literature and resources shared over social media. Evidence was synthesized, and trend categories were developed through iterative discussions among the research team.

RESULTS

Nine trend categories were uncovered, which included the digital transformation of the economy, artificial intelligence (AI)/machine learning-enhanced automation, AI-enabled human resource management systems, skill requirements for the future of work; globalization 4.0, climate change and the green economy, Gen Zs and the work environment; populism and the future of work, and external shocks to accelerate the changing nature of work. The scan highlighted that some groups of workers may be more likely to experience conditions that contribute to vulnerability, including greater exposure to job displacement or wage depression. The future of work could also create opportunities for labor market engagement.

CONCLUSION

The future of work represents an emerging public health concern. Exclusion from the future of work has the potential to widen existing social and health inequities. Thus, tailored supports that are resilient to changes in the nature and availability of work are required for workers facing vulnerability.

Health effects of climate change: an overview of systematic reviews

OBJECTIVES

We aimed to develop a systematic synthesis of systematic reviews of health impacts of climate change, by synthesising studies' characteristics, climate impacts, health outcomes and key findings.

DESIGN

We conducted an overview of systematic reviews of health impacts of climate change. We registered our review in PROSPERO (CRD42019145972). No ethical approval was required since we used secondary data. Additional data are not available.

DATA SOURCES

On 22 June 2019, we searched Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Cochrane and Web of Science.

ELIGIBILITY CRITERIA

We included systematic reviews that explored at least one health impact of climate change.

DATA EXTRACTION AND SYNTHESIS

We organised systematic reviews according to their key characteristics, including geographical regions, year of publication and authors' affiliations. We mapped the climate effects and health outcomes being studied and synthesised major findings. We used a modified version of A MeaSurement Tool to Assess systematic Reviews-2 (AMSTAR-2) to assess the quality of studies.

RESULTS

We included 94 systematic reviews. Most were published after 2015 and approximately one-fifth contained meta-analyses. Reviews synthesised evidence about five categories of climate impacts; the two most common were meteorological and extreme weather events. Reviews covered 10 health outcome categories; the 3 most common were (1) infectious diseases, (2) mortality and (3) respiratory, cardiovascular or neurological outcomes. Most reviews suggested a deleterious impact of climate change on multiple adverse health outcomes, although the majority also called for more research.

CONCLUSIONS

Most systematic reviews suggest that climate change is associated with worse human health. This study provides a comprehensive higher order summary of research on health impacts of climate change. Study limitations include possible missed relevant reviews, no meta-meta-analyses, and no assessment of overlap. Future research could explore the potential explanations between these associations to propose adaptation and mitigation strategies and could include broader sociopsychological health impacts of climate change.

Climate change, 24-hour movement behaviors, and health: a mini umbrella review

BACKGROUND

The worsening climate change and alarming prevalence of communicable and non-communicable diseases continue to threat human life and existence. Accumulating evidence suggests that favorable patterns of 24-h movement behaviors, high physical activity, low sedentary behavior, and adequate sleep, may positively contribute to achieving dual benefits of climate change mitigation and disease prevention. The purposes of this mini umbrella review were to summarize the most up-to-date, high-level evidence exploring the relationships between climate change, 24-h movement behaviors, and health and elaborate on the mechanisms linking the three variables of interest.

METHODS

A systematic search of electronic databases was performed in PubMed and Google Scholar during March-October 2020. Inclusion criteria were: (1) systematic review; (2) reviewed relationships between climate change and movement behaviors and/or health in any directions; (3) written in English; (4) published in 2010-2020. Narrative synthesis was conducted to highlight the main relationships observed and address the current state of knowledge and priorities for future research. In order to illustrate the potential mechanisms between climate change, movement behaviors, and health, the main results from included systematic reviews were summarized and a conceptual framework was developed for future research.

RESULTS

Based on the evidence from eight systematic reviews published in the past decade, multi-directional (i.e., uni-, bi-, or U-shaped) links were observed between climate change and varying human health outcomes. However, little is understood about the association between climate change and 24-h movement behaviors. Two reviews suggested the negative impact of climate change on sleep and bi-directional relationships between climate change and physical activity/sport. One review included two studies suggesting the unfavorable impact of climate change on sedentary behavior; however, the evidence was limited. Finally, no reviews examined the mechanisms by which climate change, movement behaviors, and health impact one another. Based on the findings of this mini umbrella review, a conceptual framework is proposed that could guide future work to unpack mechanisms between climate change, movement behaviors, and health.

CONCLUSIONS

This mini umbrella review highlights the importance of better understanding the mechanisms between climate change, movement behaviors, and health in developing effective mitigation and adaptation strategies to climate change, while paying close attention to vulnerable countries/communities/population groups.

Climate Change Adaptation: Prehospital Data Facilitate the Detection of Acute Heat Illness in India

Introduction

Extreme heat is a significant cause of morbidity and mortality, and the incidence of acute heat illness (AHI) will likely increase secondary to anthropogenic climate change. Prompt diagnosis and treatment of AHI are critical; however, relevant diagnostic and surveillance tools have received little attention. In this exploratory cross-sectional and diagnostic accuracy study, we evaluated three tools for use in the prehospital setting: 1) case definitions; 2) portable loggers to measure on-scene heat exposure; and 3) prevalence data for potential AHI risk factors.

Methods

We enrolled 480 patients who presented to emergency medical services with chief complaints consistent with AHI in Ahmedabad, India, from April–June 2016 in a cross-sectional study. We evaluated AHI case definition test characteristics in reference to trained prehospital provider impressions, compared on-scene heat index measured by portable loggers to weather station measurements, and identified AHI behavioral and environmental risk factors using logistic regression.

Results

The case definition for heat exhaustion was 23.8% (12.1–39.5%) sensitive and 93.6% (90.9–95.7%) specific. The positive and negative predictive values were 33.5% (20.8–49.0%) and 90.1% (88.5–91.5%), respectively. Mean scene heat index was 6.7°C higher than the mean station heat index (P < 0.001), and station data systematically underestimated heat exposure, particularly for AHI cases. Heat exhaustion cases were associated with on-scene heat index ≥ 49°C (odds ratio [OR] 2.66 [1.13–6.25], P = 0.025) and a history of recent exertion (OR 3.66 [1.30–10.29], P = 0.014), while on-scene air conditioning was protective (OR 0.29 [0.10–0.85], P = 0.024).

Conclusion

Systematic collection of prehospital data including recent activity history and presence of air conditioning can facilitate early AHI detection, timely intervention, and surveillance. Scene temperature data can be reliably collected and improve heat exposure and AHI risk assessment. Such data may be important elements of surveillance, clinical practice, and climate change adaptation.

Steps Towards Comprehensive Heat Communication in the Frame of a Heat Health Warning System in Slovenia

Occupational heat stress has an important negative impact on the well-being, health and productivity of workers and should; therefore, be recognized as a public health issue in Europe. There is no comprehensive heat health warning system in Slovenia combining public health measures with meteorological forecasts. The aim of this research was to provide insight into the development of such a system in Slovenia, turning the communication from the current meteoalarm into a broader system that has more information for different social groups. To achieve this goal, the following steps were used: Analysis of summer temperatures and issued meteoalarms, a survey of the general knowledge about heat among the public, organization and management of two stakeholder symposia, and a final survey on workers' opinions on heat stress and measures, supplemented by interviews with employers. Summer average daily temperature distributions in Slovenia changed during the investigated period (1961-2019) and the mean values increased over time by 2-3 °C. Additionally, the number of days with fulfilled yellow (potentially dangerous) and especially orange (dangerous) meteoalarm conditions increased significantly after 1990. The survey of the general public about heat stress and warnings showed that efforts to raise awareness of heat issues need to be intensified and that public health measures should effectively target vulnerable groups. Stakeholder symposia and further surveys have shown that awareness and understanding of the negative effects of heat stress on health and productivity are still quite low, so effective ways of disseminating information to different sectors while striking the best balance between efficiency, feasibility and economic cost have to be found.

Balance between Health Risks and Benefits for Outdoor Workers Exposed to Solar Radiation: An Overview on the Role of Near Infrared Radiation Alone and in Combination with Other Solar Spectral Bands

Near infrared or infrared A (IRA) accounts for over 40% of the solar spectrum (SS) and is able to reach subcutaneous tissue as well as the retina. Outdoor workers are occupationally exposed to solar radiation (SR), but the level of exposure may differ widely depending on the job performed, time spent outdoors, latitude, altitude, season, personal protection, etc. Until now, risk assessment and management for outdoor workers has focused on the prevention of both acute and long-term effects on the eye and the skin due to solar ultraviolet radiation (UVR) with little consideration of the other components of the SS (a possible exception is represented by visible radiation with reference to the eye). A growing body of evidence coming from in vitro studies indicates that IRA is involved in cellular reactive oxygen species (ROS) production and may interfere with the respiratory chain in the mitochondria. Moreover, it can modulate gene expression and some metabolic pathways. The biological action of IRA is only partly attributable to a thermal mechanism, should it be also involved in photochemical ones. The cellular and molecular pathways affected by IRA are partly similar and partly different with respect to those involved in the case of visible ultraviolet A (UVA) and ultraviolet B (UVB) radiation. Consequently, the net effect of the SS is very difficult to predict at different levels of the biological organization, making more difficult the final balance of health risk and benefits (for the skin, eye, immune system, blood pressure, etc.) in a given exposure situation. Moreover, few in vivo studies and no epidemiological data are presently available in this regard. Investigating this topic may contribute to better defining the individual exposome. More practically, it is expected to bring benefits to the risk assessment and management for outdoor workers exposed to SS, contributing to: (1) better definition of the individual profiles of susceptibility, (2) more focused preventive and protective measures, (3) better implementation of the health surveillance and (4) a more effective information and training.

The influence of climate change on human cardiovascular function

Climate change is considered to have great impact on human health. The heat waves have been associated with excess morbidity and mortality of cardiovascular diseases (CVD) across various populations and geographic locations. Important role in the heat-induced cardiovascular damage has endothelial dysfunction. It has been noticed that hot weather can impair tone and structure of the blood vessels via interfering with variety of biological factors such as nitric oxide synthesize, cytokine production and systemic inflammation. Also, due to dehydration and increased blood viscosity, by promoting thrombogenesis, heat has important impact on patients with atherosclerosis. During chronic exposure to the cold or hot weather cardiovascular function can be decreased, leading to a higher risk of developing heart attack, malignant cardiac arrhythmias, thromboembolic diseases and heat-induced sepsis like shock. It has been shown that changes in the ambient temperature through increasing blood pressure, blood viscosity, and heart rate, contribute to the cardiovascular mortality. The majority of deaths due to heat waves especially affect individuals with preexisting chronic CVD. This population can experience a decline in the health status, since extreme ambient temperature affects pharmacokinetic parameters of many cardiovascular drugs. Increased mortality from ischemic or hemorrhagic stroke can also be related to extreme temperature variations. On a cellular level, higher ambient temperature can limit storage of ATP and O₂ increase amount of free radicals and toxic substances and induce neuronal apoptotic signal transduction, which all can lead to a stroke. Preserving cardiovascular function in context of extreme climate changing tends to be particularly challenging.

Heat Stress Perception among Native and Migrant Workers in Italian Industries-Case Studies from the Construction and Agricultural Sectors

Climate change will increase the frequency and severity of hazard events such as heat waves, with important effects in several European regions. It is of importance to consider overall effects as well as specific impact on vulnerable population groups such as outdoor workers. The agricultural and construction sectors represent two strategic occupational fields that in relatively recent years involve an increasing number of migrant workers, and therefore require a better management of cultural aspects, that may interact with and impact on heat-related health risk. For this reason, the present study evaluated heat-stress perception and management among native and immigrant workers in Europe. As part of the EU’s Horizon 2020 HEAT-SHIELD project (grant agreement No. 668786), two agricultural and one construction companies, traditionally employing migrant workers, were evaluated with a questionnaire survey during the summer months of 2017. The data collected (104 case studies) were analyzed using descriptive statistics (Chi-squared tests) and the analysis of variance was performed with ANOVA test. From the results, migrant workers declared that work required greater effort than do native Italian workers (χ² = 17.1, p = 0.001) but reported less impact from heat on productivity (χ² = 10.6; p = 0.014) and thermal discomfort. In addition, migrant workers were mainly informed through written or oral communications, while native workers received information on heat-health issues through training courses. These findings are of importance for future information and mitigation actions to address socio-cultural gaps and reduce heat-stress vulnerability.