Occupational Heat Exposure Research Articles

Examining Management and Employees' Perceptions of Occupational Heat Exposure and the Effectiveness of a Heat Stress Prevention Intervention on Safety and Well-Being among Natural Gas Construction Workers: A Qualitative Field-Based Study.

Numerous risk factors have been identified as significantly influencing outdoor workers' risk for heat stress and heat-related conditions, impacting their health, well-being, and productivity. However, the specific effects of these factors on construction workers' safety, health, and well-being remain under-researched. With climate change increasing temperatures, assessing heat stress among construction workers is imperative. To identify the barriers and facilitators influencing the safety of natural gas construction workers and evaluate an implemented heat stress intervention. In the summer of 2023, two semi-structured interviews and six focus groups were conducted with twenty-one stakeholders at a Texas natural gas construction site. Key facilitators include employee preparedness, use of employer-provided resources, hydration logs, and real-time communication tools. Contrarily, the barriers include daily work schedules, access to dehydrating beverages, and generational differences with the non-implementation of mandatory rest breaks. The heat stress program was perceived as effective, surpassing recommended guidelines. To advance construction workers' safety, health, and well-being, both employee involvement and employer management are needed, along with no-cost accessible resources. Additionally, implementing a required routine rest break and comprehensive heat stress education, particularly for older workers, will significantly promote safety and safe work practices in hot environments. Note: in this study, the terms 'worker' and 'employee' are used interchangeably.

Occupational heat exposure and its impact on kidney health among cashew workers.

Rising temperatures increase workers' risk of heat-related illnesses due to heat stress (HS). Chronic Kidney Disease of unknown etiology (CKDu) is rising in non-agricultural workers in hot climates. Dehydration, heat stress, and physical exertion can damage cashew workers' kidney health. In 2020-2021, 262 cashew workers in Cuddalore, Tamil Nadu were assessed for Wet Bulb Globe Temperature (WBGT), and job-specific American Conference of Governmental Industrial Hygienists standard was used to evaluate workload. "High heat-exposed" meant heat stress exceeded the Threshold Limit Value for safe manual work (27.5°C for heavy and 28°C for moderate physical activity). Heat Strain Indicators (HSIs) such as Tympanic Temperature (Ttemp), Sweat Rate (SwR), Urine Specific Gravity (USG), and urine dipstick parameters were measured in all workers, however serum creatinine was measured only in 100 workers. Glomerular Filtration Rate(eGFR) was calculated using theCKD-EPIequation. A standardized questionnaire assessed heat-related health symptoms. Over 65% of workers experienced wet bulb globe temperature exposures exceeding the threshold limit value (Avg.- wet bulb globe temperature 30.4°C ± 1.8°C). Ninety-five percent of heat-exposed workers experienced at least one of the physiological heat strain indicators. The risk of urogenital symptoms was 7.7 times greater among high-heat-exposed workers (95% CI 3.4-17.1), which corroborates well with the measured post shift urine specific gravity (37%). Despite controlling for relevant confounders (age & gender), high-heat-exposed workers had 3.5-fold higher odds of eGFR < 90ml/min/1.73m2 compared to less-exposed workers (95% CI 1.1-10.6). Persistent heat stress promotes heat-related disorders in cashew workers and lowers eGFR. This needs further investigation to determine its longer term effects on kidney function. Workplace cooling solutions that reduce heat stress are critically needed to protect thekidneys and ensureoccupational health.

Climate change and heat stress resilient outdoor workers: findings from systematic literature review

PurposeGlobal warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially those working outdoors, as they often have limited access to cooling strategies. The present systematic literature review (a) summarizes the current knowledge on the impacts of climate change on outdoor workers, (b) provides historical background on this issue, (c) explores factors that reduce and increase thermal stress resilience, (d) discusses the heat mitigation strategies, and (e) provides an overview of existing policy and legal frameworks on occupational heat exposure among outdoor workers.Materials and methodsIn this systematic review, we searched scientific databases including Scopus (N = 855), Web of Science (N = 828), and PubMed (N = 202). Additionally, we identified relevant studies on climate change and heat-stress control measures through Google Scholar (N = 116) using specific search terms. In total, we monitored 2001 articles pertaining to worker populations (men = 2921; women = 627) in various outdoor climate conditions across 14 countries. After full-text assessment, 55 studies were selected for inclusion, and finally, 29 eligible papers were included for data extraction.ResultsFailure to implement effective control strategies for outdoor workers will result in decreased resilience to thermal stress. The findings underscore a lack of awareness regarding certain adaptation strategies and interventions aimed at preventing and enhancing resilience to the impact of climate change on heat stress prevalence among workers in outdoor tropical and subtropical environments. However, attractive alternative solutions from the aspects of economic and ecological sustainability in the overall assessment of heat stress resilience can be referred to acclimatization, shading, optimized clothing properties and planned breaks.ConclusionThe integration of climate change adaptation strategies into occupational health programs can enhance occupational heat resilience among outdoor workers. Conducting cost-benefit evaluations of health and safety measures for thermal stress adaptation strategies among outdoor workers is crucial for professionals and policymakers in low- and middle-income tropical and subtropical countries. In this respect, complementary measures targeting hydration, work-rest regimes, ventilated garments, self-pacing, and mechanization can be adopted to protect outdoor workers. Risk management strategies, adaptive measures, heat risk awareness, practical interventions, training programs, and protective policies should be implemented in hot-dry and hot-humid climates to boost the tolerance and resilience of outdoor workers.

Occupational Risks of Agricultural Workers Exposed to Heat: Literature Review

Proposal: The aim of this study is to conduct a literature review on the occupational hazards of agricultural workers exposed to heat while carrying out their activities. Theoretical Framework: Heat exposure poses a serious occupational risk for agricultural workers, increasing the incidence of dehydration, heat exhaustion, and sunstroke. Method: The methodology adopted for this research involves a literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) methodology. Data collection was carried out through a bibliographic survey from the period 2005 to 2024 in the Pubmed, Web of Science, and Scopus databases. The search used keywords such as "risks," "workers," "agriculture," and "heat." Results and Discussion: The results revealed the selection of 109 articles, and after reading the abstracts, those that did not align with the research proposal were excluded. After filtering, 07 articles remained, whose topics showed affinity with the research. The literature points to a growing trend of studies addressing thermal discomfort as an occupational hazard, prevalent in open and semi-open environments. Specific studies for certain agricultural operations, such as groups of workers dealing with grain dryers and furnaces, are scarce and have limited conclusions. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied or influence practical aspects in the field of occupational heat exposure for agricultural workers. These implications can encompass various sectors of post-harvest grain processing. Originality/Value: This study contributes to the literature by gathering information published in different databases on occupational heat exposure. The significance and value of this research are highlighted by a limited number of works in the literature, stressing the need for further research in the field. Based on this premise, more studies on agricultural work in heat-prone environments and consequent thermal discomfort should be encouraged to stimulate discussions on actions to eliminate the risks involved in these operations.

Risk factors associated with indicators of dehydration among migrant farmworkers

ObjectiveFarmworkers are at increased risk of adverse health outcomes related to occupational heat exposure and inadequate access to water, shade, or rest breaks. Presently, there is a dearth of studies examining the prevalence of dehydration and related factors in U.S. farmworkers. Our objectives were to characterize hydration status during typical workdays and to identify risk factors associated with increased dehydration in migrant farmworkers employed in Florida. MethodsUrine samples were collected and analyzed for urine specific gravity (USG) 2–3 times per person per day over five days in May 2021 and 2022. Data collection included demographic characteristics, wet-bulb-globe-temperature (WBGT), and information on working conditions (task type, duration, and crop units harvested), fluid intake, clothing worn, and heat safety behaviors. Multivariable mixed regression models were used to evaluate risk factors associated with change in USG levels (continuous) during a work shift. ResultsA total of 111 farmworkers participated in this study providing 1020 cumulative USG measurements, of which 96.8% of end-of-shift USG samples were above 1.020 indicating potential dehydration. In multivariable models, dehydration assessed using change in USG levels significantly declined with age (β = −0.078; 95%CI: 0.150, −0.006) but showed significant increase with body mass index (β = 0.016; 95%CI: 0.003, 0.028), WGBT (β = 0.054; 95%CI:0.044, 0.064), mean shift duration, and state of primary residence. We did not find significant associations of dehydration with type of clothing worn, intake of employer-provided water, or crop units harvested during a shift in this sample of farmworkers. ConclusionOur findings underscore the need for additional research to evaluate adverse outcomes related to dehydration and to better understand recovery patterns from chronic dehydration across workweeks and harvest seasons in migrant farmworkers.

Impact of occupational heat exposure on selected haematological parameters of bakery workers: A comprehensive study in Ilorin, Kwara State.

The Occupational Health and Safety Administration has identified indoor industries at risk of experiencing heat-related illnesses due to the presence of heat-generating appliances; these include bakeries, kitchens, laundries, and furnaces. This study aimed to assess the effects of heat stress on haematological parameters and erythrocyte sedimentation rates (ESR) of bakery workers in Ilorin, Kwara State. It was a cross-sectional study, involving laboratory analysis, which lasted for 3 months. A total of 60 Male and female bakery workers aged between 18 and 65 years with 1 or more years of working experience were recruited for this study. Full blood count estimation was carried out using haematological analyzer (Sysmex-2000) and the ESR was carried out using the Westergren method in the Haematology unit, Kwara State University, Malete. Results were analyzed using SPSS version 20. This study found the bakery workers to have low ESR (2.13 ± 1.28) compared to (10.05 ± 4.95) of the control, the RBC was high (6.708 ± 2.08) compared to (5.46 ± 1.12) of the control group. TWBC was also found to be high (7.425 ± 1.74) compared to (6.95 ± 2.49) of the control population. Findings from this study concluded that working under high temperatures negatively affected the health of bakery workers with reports of heat stress-related symptoms and also affected ESR and haematological parameters. A comprehensive and effective national occupational health and safety program that includes relevant policies, decrees, and proper enforcement is needed to ensure the worker's safety and health both in the formal and the fast-growing informal sectors.

Risky working conditions and chronic kidney disease

BackgroundIndividuals in the workplace are exposed to various environments, tasks, and schedules. Previous studies have indicated a link between occupational exposures and an increased risk of chronic kidney disease (CKD). However, the social conditions of the work environment may also be a crucial contributing factor to CKD. Furthermore, individuals may encounter multiple occupational-related risk factors simultaneously, underscoring the importance of investigating the joint risk of different working conditions on CKD.MethodsA prospective analysis of 65,069 UK Biobank participants aged 40 to 69 years without CKD at baseline (2006–2010) was performed. A self-administered questionnaire assessed working conditions and a working conditions risk score were developed. Participants who answered “sometimes” or “often” exposure to occupational heat or occupational secondhand cigarette smoke; involved in shift work or heavy workloads (“usually” or “always”), were grouped as high-risk working conditions. Each working condition was scored as 1 if grouped as high-risk, and 0 if not. The working conditions risk score was equal to the sum of these four working conditions. Cox proportional hazard regression models were used to estimate the associations between working conditions and CKD incidence.ResultsThe mean follow-up time was 6.7 years. After adjusting for demographic, lifestyle, and working time factors, the hazard ratios for the development of CKD for heavy workloads, shift work, occupational secondhand cigarette smoke exposure, and occupational heat exposure were 1.24 (95%CI = 1.03, 1.51), 1.33 (95%CI = 1.10, 1.62), 1.13 (95%CI = 1.01, 1.26), 1.11 (95%CI = 0.99, 1.24), respectively. The risk of CKD was found to be significantly associated with an increasing working conditions risk score. Individuals with a working conditions risk score of 4 had an 88.0% (95% CI = 1.05, 3.35) higher risk of developing CKD when compared to those with a working conditions risk score of 0.ConclusionsAdverse working conditions, particularly when considered in combination, can significantly elevate the risk of chronic kidney disease (CKD). These results provide a reference for implementing measures to prevent CKD.

Heat stress and adverse pregnancy outcome: Prospective cohort study.

To explore the relationship between occupational heat exposure, physiological heat strain indicators and adverse outcomes in pregnant women. Prospective cohort. Workplaces in Tamil Nadu, India. A cohort of 800 pregnant women engaged in moderate to heavy physical work in 2017-2019 and 2021-2022. Participants were recruited at between 8 and 14 weeks of gestation. Occupational heat exposure and heat strain indicators were captured each trimester. 'Heat exposed' was defined as heat stress exceeding the threshold limit value (TLV) for safe manual work (with maximum wet-bulb globe temperatures of 27.5°C for a heavy workload and 28.0°C for a moderate workload). Physiological heat strain indicators (HSIs) such as core body temperature (CBT) and urine specific gravity (USG) were measured before and after each shift. Heat-related health symptoms were captured using the modified HOTHAPS questionnaire. The main outcome measures included (1) a composite measure of any adverse pregnancy outcome (APO) during pregnancy (including miscarriage, preterm birth, low birthweight, stillbirth, intrauterine growth restriction and birth defects), (2) a composite measure of adverse outcomes at birth (3) and miscarriage. Of the 800 participants, 47.3% had high occupational heat exposure. A rise in CBT was recorded in 17.4% of exposed workers, and 29.6% of workers experienced moderate dehydration (USG ≥ 1.020). Heat-exposed women had a doubled risk of miscarriage (adjusted odds ratio, aOR 2.4; 95% confidence interval, 95% CI 1.0-5.7). High occupational heat exposure was associated with an increased risk of any adverse pregnancy and foetal outcome (aOR 2.3; 95% CI 1.4-3.8) and adverse outcome at birth (aOR 2.0; 95% CI 1.2-3.3). High occupational heat exposure is associated with HSIs and adverse pregnancy outcomes in India.

Associations of occupational heat exposure and stomach cancer in a population-based case-control study

Associations of occupational heat exposure and stomach cancer in a population-based case-control study

Impact of occupational heat exposure on blood lipids among petrochemical workers: An analysis of 9-year longitudinal data

Impact of occupational heat exposure on blood lipids among petrochemical workers: An analysis of 9-year longitudinal data

Considerations for occupational heat exposure: A scoping review

The ability to regulate core body temperature is a critical factor in avoiding occupational heart stress in demanding environments. Heat-related illness in an occupational setting is complex and multifactorial and includes environment (intrinsic and extrinsic), the occupational clothing requirements and physiological factors. Much of this research began in the gold mines in South Africa after several miners died due to heat related illness. Similar research was conducted during World War Two and was crucial for the creation of acclimatization techniques and strategies for acquiring thermal tolerance. Techniques such as fatigue recovery and body cooling are still used today to prevent heat related illness in individuals with occupations that have frequent exposure to heat and high physical loads. These individuals are at greater risk of heat related illness as extended exposure to a hot or humid environment in combination with strenuous physical activity can overwhelm the body’s homeostatic cooling mechanisms. In addition, individuals from special populations with chronic or acute health impacts such as diabetes mellitus, also have a greater risk for the aforementioned. Currently, there are several heat prevention strategies, including training and education, regulation and monitoring, in place to protect workers from heat related illness and casualty. These strategies, along with future considerations and the impact of climate change will be highlighted in this review.

Retention of Agricultural Workers Participating in a Renal Longitudinal Study

ABSTRACT Objectives The relationship between heat stress, chronic kidney diseases and acute kidney injury has been documented in cross-sectional studies with agricultural workers. However, only a few international studies have assessed renal function in agricultural workers longitudinally. Our research study, Occupational Heat Exposure and Renal Dysfunction (OHEaRD) is the first longitudinal study in the U.S. that monitored renal function in agricultural workers five times over the course of 32-months. The main objectives of this study were to evaluate the rate of retention and identify predictors associated with retention in a longitudinal study with agricultural workers. Methods In January 2020, we enrolled 119 Florida agricultural workers to observe on 5 workdays over 32 months. Retention was defined by the number of follow-up visits that a participant attended, the consistency of visit attendance, and attendance at the last visit. Participants were provided hemoglobin A1C, lipid panel, creatinine measurement, glomerular filtration rate (eGFR), blood pressure, and body mass index results and an incentive gift card were handed out to participants at each visit. Results Four enrollees did not participate on any workday, thus analysis concentrated on the remaining 115 participants. The majority of participants (64%) completed the 32-month study, 78% completed at least 4 visits, and 55% completed all 5 visits. The statistically significant predictors of higher retention among this study were being older in age (p=0.02), Mexican nationality (p=0.004), working in ferneries (p=0.009), more years working in agriculture (p=0.02), and higher total cholesterol (p=0.02). Appreciation for the health tests was associated with greater participation at the final visit (p=0.01). Conclusion Retention in longitudinal studies is crucial to better understand kidney disease among agricultural workers, an understudied population. Participants reported valuing the access to health results, indicating that implementing point-of-care health screenings and providing the health results to each participant is a good retention strategy. There was some evidence that a participant living with or being related to a fellow co-participant could impact retention as they either showed up or missed visits together, suggesting recruiting from the same household may reduce retention.

The Burdens of Occupational Heat Exposure-related Symptoms and Contributing Factors Among Workers in Sugarcane Factories in Ethiopia: Heat Stress Wet Bulb Globe Temperature Meter

BackgroundHeat stress is a harmful physical hazard in many occupational settings. However, consequences of occupational heat exposure among workers in a sugarcane factory in Ethiopia are not well characterized. This study aimed to assess the level of occupational heat exposure-related symptoms and contributing factors. MethodsIn this cross-sectional study, five workstations were selected for temperature measurement. Heat stress levels were measured using a wet-bulb globe temperature index meter. A stratified random sampling technique was used to select 1,524 participants. Heat-related symptoms were assessed using validated questionnaires. ResultsThe level of occupational heat exposure was 72.4% (95% CI: 70.2%–74.8%), while 71.6% (95% CI: 69.3%–74.9%) of participants experienced at least one symptom related to heat stress. The most common heat-related symptoms were swelling of hands and feet (78%), severe thirst (77.8%) and dry mouth (77.4%). The identified risk factors were a lack of reflective shields (AOR: 2.20, 95% CI: 1.53, 3.17), not-enclosed extreme heat sources (AOR: 1.76, 95% CI: 1.23, 2.51), a lack of access to shade (AOR: 9.62, 95% CI: 6.20, 14.92), and inappropriate protective clothing provision (AOR: 1.58, 95% CI: 1.27, 2.71). ConclusionsThe burden of occupational heat exposure and heat-induced symptoms was high. Lack of reflective shields, the absence of enclosed extreme heat sources, a lack of access to shade, and inappropriate protective clothing provision were considerable attributes of heat stress. Therefore, the use of mechanical solutions to stop heat emissions at their sources and the key factors identified were areas for future intervention.

Occupational heat stress, heat-related effects and the related social and economic loss: a scoping literature review.

While there is consistent evidence on the effects of heat on workers' health and safety, the evidence on the resulting social and economic impacts is still limited. A scoping literature review was carried out to update the knowledge about social and economic impacts related to workplace heat exposure. The literature search was conducted in two bibliographic databases (Web of Science and PubMed), to select publications from 2010 to April 2022. A total of 89 studies were included in the qualitative synthesis (32 field studies, 8 studies estimating healthcare-related costs, and 49 economic studies). Overall, consistent evidence of the socioeconomic impacts of heat exposure in the workplace emerges. Actual productivity losses at the global level are nearly 10% and are expected to increase up to 30-40% under the worst climate change scenario by the end of the century. Vulnerable regions are mainly low-latitude and low- and middle-income countries with a greater proportion of outdoor workers but include also areas from developed countries such as southern Europe. The most affected sectors are agriculture and construction. There is limited evidence regarding the role of cooling measures and changes in the work/rest schedule in mitigating heat-related productivity loss. The available evidence highlights the need for strengthening prevention efforts to enhance workers' awareness and resilience toward occupational heat exposure, particularly in low- and middle-income countries but also in some areas of developed countries where an increase in frequency and intensity of heat waves is expected under future climate change scenarios.

Working in heat: Contrasting heat management approaches among outdoor employees and contractors

Exposure to high heat and humidity in the workplace is a critical health and safety issue. In Australia, where heat waves are occurring with more frequency and intensity the risks posed by occupational heat exposure have been acknowledged by employer groups, trade unions, and statutory government agencies. In this study we investigate the employment context in which heat stress is experienced, and whether the mode of employment affects the capacity to manage it. We examine the experience of workplace heat exposure for two groups of affected outdoor workers: contracted pieceworkers in bicycle delivery and permanently employed municipal workers in parks and road maintenance. Data was collected in Sydney during the summer of 2019 via surveys and in-person interviews with the two sets of workers. Research findings reflect the well-established nexus between outside temperature, humidity and work effort in producing heat stress. The comparative findings reveal that more secure forms of employment enable social organisation and workflow to manage heat stress and that, conversely, more contingent forms of employment such as contractual piece work can exacerbate exposure. The research demonstrates that the mode of employment has a direct bearing on the capacity to address workplace heat stress: growth in contract or ‘gig’ work may exacerbate impacts; this issue is likely to become more important with advancing climate change.

Overexertion and heat stress in the fire service: a new conceptual framework.

From the year 2000, the United States Fire Administration (USFA) has been recording all line-of-duty deaths in the fire service. Stress or overexertion caused 1096 out of 2598 total line-of-duty deaths in the United States from 2000 to 2021. Those deaths due to stress or overexertion were further classified as myocardial infarction (90%), cerebrovascular accident (6.8%), other (2.6%), and heat exhaustion (0.6%). Environmental heat exposure is a concern in firefighting, as firefighters work in extreme conditions, such as high ambient temperatures, while wearing protective clothing. Heat stress is not only hazardous to the cardiovascular system, but may accentuate muscle fatigue and overexertion. In addition, overexertion itself is related to increased incidence of musculoskeletal injuries, usually to the lower extremities. Further, there is a strong physiological mechanistic link to suggest that the increased occupational heat exposure and thermoregulatory strain firefighters experience may be a stressor that increases the risk of injuries. This commentary hopes to show the need for further research on the effects of occupational exposures and physiological strain in the fire service.

Association of occupational heat exposure and colorectal cancer in the MCC-Spain study.

Heat exposure and heat stress/strain is a concern for many workers. There is increasing interest in potential chronic health effects of occupational heat exposure, including cancer risk. We examined potential associations of occupational heat exposure and colorectal cancer (CRC) risk in a large Spanish multi-case--control study. We analyzed data on 1198 histologically confirmed CRC cases and 2690 frequency-matched controls. The Spanish job-exposure matrix, MatEmEsp, was used to assign heat exposure estimates to the lifetime occupations of participants. Three exposure indices were assessed: ever versus never exposed, cumulative exposure and duration (years). We estimated odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression adjusting for potential confounders. Overall, there was no association of ever, compared with never, occupational heat exposure and CRC (OR 1.09, 95% CI 0.92-1.29). There were also no associations observed according to categories of cumulative exposure or duration, and there was no evidence for a trend. There was no clear association of ever occupational heat exposure and CRC in analysis conducted among either men or women when analyzed separately. Positive associations were observed among women in the highest categories of cumulative exposure (OR 1.81, 95% CI 1.09-3.03) and duration (OR 2.89, 95% CI 1.50-5.59) as well as some evidence for a trend (P<0.05). Overall, this study provides no clear evidence for an association between occupational heat exposure and CRC.

Outdoor work: past, present, and future on occupational heat exposure

Resumo Considerando as mudanças climáticas e o impacto das temperaturas elevadas na saúde humana, especialmente devido ao aquecimento global, são relevantes as ações de prevenção ao calor voltadas aos trabalhadores que laboram a céu aberto. Neste ensaio, são apresentados resultados de recentes pesquisas, bem como destacadas inovações tecnológicas para monitoramento do calor no Brasil. Também são expostas reflexões sobre o futuro do trabalho a céu aberto diante das mudanças climáticas. O trabalho a céu aberto é em geral caracterizado por atividades pesadas, que geram elevado calor metabólico. Contudo, são escassos os esforços no campo da Saúde e Segurança do Trabalho para a busca de alternativas que minimizem ou eliminem os efeitos do calor para os trabalhadores. Além disso, as alternativas de proteção dos trabalhadores são reduzidas. O Monitor IBUTG é apresentado como inovação tecnológica de monitoramento remoto do calor em ambiente a céu aberto. Apesar das medidas de controle previstas em lei para proteção dos trabalhadores submetidos ao calor, em razão do aquecimento global, serão necessários intervenções inovadoras e controles especiais da exposição ao calor nos ambientes externos. Portanto, é desejável maior empenho na produção de conhecimento com vistas a fomentar a elaboração ou o aprimoramento de políticas públicas.

Occupational heat exposure and prostate cancer risk: A pooled analysis of case-control studies

BackgroundHeat exposures occur in many occupations. Heat has been linked to key carcinogenic processes, however, evidence for associations with cancer risk is sparse. We examined potential associations between occupational heat exposure and prostate cancer risk in a multi-country study. MethodsWe analysed a large, pooled dataset of 3142 histologically confirmed prostate cancer cases and 3512 frequency-matched controls from three countries: Canada, France, and Spain. Three exposure indices: ever exposure, lifetime cumulative exposure and duration of exposure, were developed using the Finnish Job-Exposure Matrix, FINJEM, applied to the lifetime occupational history of participants. We estimated odds ratios (ORs) and 95% confidence intervals (CIs), using conditional logistic regression models stratified by 5-year age groups and study, adjusting for potential confounders. Potential interactions with exposure to other occupational agents were also explored. ResultsOverall, we found no association for ever occupational heat exposure (OR 0.97; 95% CI 0.87, 1.09), nor in the highest categories of lifetime cumulative exposure (OR 1.04; 95% CI 0.89, 1.23) or duration (OR 1.03; 95% CI 0.88, 1.22). When using only the Spanish case-control study and a Spanish Job Exposure Matrix (JEM), some weakly elevated ORs were observed. ConclusionsFindings from this study provide no clear evidence for an association between occupational heat exposure and prostate cancer risk.

Occupational heat exposure alone does not explain chronic kidney disease of uncertain aetiology (CKDu) in Sri Lanka

• The association of occupational heat exposure with CKDu remains debated. • kidney function of individuals in three occupational groups, farmers, fisherfolk and plantation workers in Sri Lanka was assessed. • CKDu risk was lowest in occupational group with highest heat exposure. • CKDu risk was higher among farmers and workers with low to moderate heat exposure. • Heat stress does not appear to be the main driver of CKDu. Chronic kidney disease of uncertain aetiology (CKDu) is an emerging health concern in tropical farming communities. The role ofoccupational heat exposure as a potential driver of CKDu remains debated. Our study examines occupational heat exposure kidney health in three occupational groups in Sri Lanka. We recruited participants from three occupational groups from three climatic zones; fisherfolk from the dry and intermediate zones (N=225), paddy farmers from the intermediate zone (N=180) and tea plantation workers from the wet zone (N=70). Serum creatinine, cystatin-C, urea and uric acid, estimated glomerular filtration rate and urinary albumin-creatinine ratio were used as diagnostic criteria of renal impairment. CKDu susceptibility was at the highest among farmers (13.33%), with a significant differentce compared to the fisherfolk (5.36%; p=0.0003). Among the plantation workers, CKDu susceptibility was 5.71%, and it was not significantly different compared to the farmers (p=0.087) and the fisherfolk (p=0.427). Despite higher exposure to heat stress and dehydration, as indicated by the highest simplified wet bulb globe temperature (sWBGT) in the work environments, fisherfolk reported the lowest CKDu susceptibility, while farmers and workers with low to moderate heat exposure showed an increased incidence of abnormal renal function. Further, a multivariable regression analysis identified a significant effect of occupation (p=0.005), agrochemical exposure (p=0.001) and age (p=0.001) on the likelihood of CKDu susceptibility while the sWBGT in the working environments showed no significant effect (p=0.227). With the evidence from our findings, heat exposure alone does not appear to be the leading driver of CKDu in Sri Lanka, suggesting that the nephropathy is more likely to be associated with occupational risks such as agrochemical exposures.