Extreme heat and work injuries in Kuwait's hot summers.

BACKGROUND: Hot, desert Gulf countries are host to millions of migrant workers doing outdoor jobs such as construction and hospitality. The Gulf countries apply a summertime ban on midday work to protect workers from extreme heat, although without clear evidence of effectiveness. We assessed the risk of occupational injuries associated with extreme hot temperatures during the summertime ban on midday work in Kuwait. METHODS: We collected daily occupational injuries in the summer months that are reported to the Ministry of Health's Occupational Health Department for 5 years from 2015 to 2019. We fitted generalised additive models with a quasi-Poisson distribution in a time series design. A 7-day moving average of daily temperature was modelled with penalised splines adjusted for relative humidity, time trend and day of the week. RESULTS: During the summertime ban, the daily average temperature was 39.4°C (±1.8°C). There were 7.2, 7.6 and 9.4 reported injuries per day in the summer months of June, July and August, respectively. Compared with the 10th percentile of summer temperatures in Kuwait (37.0°C), the average day with a temperature of 39.4°C increased the relative risk of injury to 1.44 (95% CI 1.34 to 1.53). Similarly, temperatures of 40°C and 41°C were associated with relative risks of 1.48 (95% CI 1.39 to 1.59) and 1.44 (95% CI 1.27 to 1.63), respectively. At the 90th percentile (42°C), the risks levelled off (relative risk 1.21; 95% CI 0.93 to 1.57). CONCLUSION: We found substantial increases in the risk of occupational injury from extremely hot temperatures despite the ban on midday work policy in Kuwait. 'Calendar-based' regulations may be inadequate to provide occupational heat protections, especially for migrant workers.

Precarious employment and occupational injuries in Sweden between 2006 and 2014: a register-based study.

BACKGROUND: Precarious employment (PE) has been suggested as a risk factor for occupational injuries (OIs). However, several issues such as under-reporting and time at risk pose obstacles to obtaining unbiased estimates of risk OBJECTIVE: To investigate if PE is a risk factor for OIs in Sweden. METHODS: This register-based study included employed workers aged 18-65, resident in Sweden between 2006 and 2014. PE was operationalised as a multidimensional construct (score) and by its five items (contract insecurity, contractual temporariness, multiple jobs/multiple sectors, income level, collective bargaining agreement). Our outcome was OI in the following year. Pooled ORs for OIs in relation to PE and PE items were calculated by means of multivariate logistic regression models for women and men separately. RESULTS: Precarious workers were at lower risk of OIs as compared with non-precarious workers among both males and females (OR <1) also when applying weights for under-reporting and adjusting for time at risk (part-time work). Male agencies workers had a higher risk of OIs (OR 1.19, 95% CI 1.15 to 1.23), as did male and female workers in multiple jobs/sectors (OR 1.25, 95% CI 1.23 to 1.28 and OR 1.10, 95% CI 1.07 to 1.13 respectively), and female workers in the low-income groups (OR 1.11, 95% CI 1.09 to 1.12). Low coverage of collective bargaining agreements was associated with a lower risk of OIs for both men and women (OR 0.30, 95% CI 0.29 to 0.31 and OR 0.26, 95% CI 0.24 to 0.27, respectively). CONCLUSIONS: While several mechanisms may explain why precarious workers in Sweden present lower risks of OIs, several dimensions of PE such as temp agency work and multiple job-holding could be important risk factors for OIs and merit further research.

Markers of kidney tubular and interstitial injury and function among sugarcane workers with cross-harvest serum creatinine elevation.

OBJECTIVES: Serum creatinine (SCr) is a routine marker of kidney injury but also increases with dehydration and muscular work. This study was to elucidate whether increase in SCr is associated with more specific markers of kidney tubular and interstitial injury and function, during prolonged heat stress among workers at high risk of chronic kidney disease of non-traditional origin (CKDnt). METHODS: Urine monocyte chemoattractant protein-1 (MCP-1), kidney injury molecule-1 (KIM-1), calbindin, glutathione S-transferase-π (GST-π), clusterin, interleukin 18 and albumin, fractional excretion of potassium (FEK), blood haemoglobin, serum potassium, ferritin and erythropoietin were measured before and after harvest in a sample of 30 workers with a ≥0.3 mg/dL SCr increase across harvest (cases), and 53 workers with stable SCr (controls). RESULTS: Urine MCP-1 (p for differential cross-harvest trend <0.001), KIM-1 (p=0.002), calbindin (p=0.02), GST-π (p=0.04), albumin (p=0.001) and FEK (p<0.001) increased in cases, whereas blood haemoglobin (p<0.001) and serum erythropoietin (p<0.001) decreased. CONCLUSION: Several markers of tubular and interstitial injury and function changed as SCr increased across a harvest season, supporting the use of SCr as an indicator of kidney injury in physically active workers regularly exposed to heat stress. Repeated injury similar to that described here, and continued work under strenuous and hot conditions with similarly elevated injury markers is likely to worsen and possibly initiate CKDnt.

Under-reporting of non-fatal occupational injuries among precarious and non-precarious workers in Sweden.

BACKGROUND: Under-reporting of occupational injuries (OIs) among precariously employed workers in Sweden challenges effective surveillance of OIs and targeted preventive measures. OBJECTIVE: To estimate the magnitude of under-reporting of OIs among precarious and non-precarious workers in Sweden in 2013. METHODS: Capture-recapture methods were applied using the national OIs register and records from a labour market insurance company. Employed workers 18-65 resident in Sweden in 2013 were included in the study (n=82 949 OIs). Precarious employment was operationalised using the national labour market register, while injury severity was constructed from the National Patient Register. Under-reporting estimates were computed stratifying by OIs severity and by sociodemographic characteristics, occupations and precarious employment. RESULTS: Under-reporting of OIs followed a dose-response pattern according to the levels of precariousness (the higher the precarious level, the higher the under-reporting) being for the precarious group (22.6%, 95% CI 21.3% to 23.8%), followed by the borderline precarious (17.6%, 95% CI 17.1% to 18.2%) and lastly the non-precarious (15.0%, 95% CI 14.7% to 15.3%). Under-reporting of OIs, decreased as the injury severity increased and was higher with highest level of precariousness in all groups of severity. We also observed higher under-reporting estimates among all occupations in the precarious and borderline precarious groups as compared with the non-precarious ones. CONCLUSIONS: This is the first register-based study to empirically demonstrate in Sweden that under-reporting of OIs is 50% higher among precariously employed workers. OIs under-reporting may represent unrecognised injuries that especially burden precariously employed workers as financial, health and social consequences shift from the employer to the employee.

Occupational heat exposure and the risk of chronic kidney disease of nontraditional origin in the United States.

Occupational heat exposure is linked to the development of kidney injury and disease in individuals who frequently perform physically demanding work in the heat. For instance, in Central America, an epidemic of chronic kidney disease of nontraditional origin (CKDnt) is occurring among manual laborers, whereas potentially related epidemics have emerged in India and Sri Lanka. There is growing concern that workers in the United States suffer with CKDnt, but reports are limited. One of the leading hypotheses is that repetitive kidney injury caused by physical work in the heat can progress to CKDnt. Whether heat stress is the primary causal agent or accelerates existing underlying pathology remains contested. However, the current evidence supports that heat stress induces tubular kidney injury, which is worsened by higher core temperatures, dehydration, longer work durations, muscle damaging exercise, and consumption of beverages containing high levels of fructose. The purpose of this narrative review is to identify occupations that may place US workers at greater risk of kidney injury and CKDnt. Specifically, we reviewed the scientific literature to characterize the demographics, environmental conditions, physiological strain (i.e., core temperature increase, dehydration, heart rate), and work durations in sectors typically experiencing occupational heat exposure, including farming, wildland firefighting, landscaping, and utilities. Overall, the surprisingly limited available evidence characterizing occupational heat exposure in US workers supports the need for future investigations to understand this risk of CKDnt.

Organisational factors and under-reporting of occupational injuries in Sweden: a population-based study using capture-recapture methodology.

OBJECTIVE: To estimate the magnitude of under-reporting of non-fatal occupational injuries (OIs) by different organisational factors in Sweden for the year 2013. METHODS: Capture-recapture methods were applied using two data sources: (1) the national OI register and (2) records from a labour market insurance company. To assure comparability of data sources, the analysis was restricted to the public sector and private companies with at least 50 employees. OIs were matched using personal identification number and reported injury dates (±7 days). Organisational factors were obtained from the national labour market register and injury severity (no healthcare/only outpatient/hospitalised) from the National Patient Register. Total number of OIs and ascertainment by data sources were estimated assuming data source independence. RESULTS: There were an estimated 98 493 OIs in 2013. Completeness of reporting OIs to the national register and to the insurance company was estimated at 73% and 43%, respectively. No report to either source was estimated at 15 000 OIs (~15%). Under-reporting to the national register differed by selected organisational factors, being higher among organisations in the public sector, those with more females, with a younger workforce and with a higher proportion of immigrants. Overall under-reporting was more common in agriculture (19.7%), other services (19.3%), commerce and hospitality (19.1%), health (18.4%) and education (18.4%). Under-reporting decreased as injury severity increased, with little variations across sectors of economic activity. CONCLUSIONS: Results suggest considerable under-reporting of OIs in Sweden and differential under-reporting by organisational factors. Results are relevant for official estimates of burden and for setting priorities for workplace safety and prevention.

Preventing kidney injury among sugarcane workers: promising evidence from enhanced workplace interventions.

OBJECTIVES: To assess if improvement of working conditions related to heat stress was associated with improved kidney health outcomes among sugarcane harvest workers in Chichigalpa, Nicaragua, a region heavily affected by the epidemic of chronic kidney disease of non-traditional origin. METHODS: Based on our findings during the 2017-2018 harvest (harvest 1), recommendations that enhanced the rest schedule and improved access to hydration and shade were given before the 2018-2019 harvest (harvest 2). Actual work conditions during harvest 2 were then observed. Serum creatinine (SCr) was measured before and at end-harvest, and cross-harvest changes in estimated glomerular filtration rate (eGFR) and incident kidney injury (IKI, ie, SCr increase by ≥0.30 mg/dL or ≥1.5 times the baseline value) were compared between harvest 1 and harvest 2 for three jobs with different physical workloads using regression modelling. Workers who left during harvest were contacted at home, to address the healthy worker selection effect. RESULTS: In burned cane cutters, mean cross-harvest eGFR decreased 6 mL/min/1.73 m2 (95% CI 2 to 9 mL/min/1.73 m2) less and IKI was 70% (95% CI 90% to 50%) lower in harvest 2 as compared with harvest 1 data. No such improvements were seen among seed cutters groups with less successful intervention implementation. CONCLUSION: Kidney injury risk was again elevated in workers with strenuous jobs. The results support further efforts to prevent kidney injury among sugarcane workers, and other heat-stressed workers, by improving access to water, rest and shade. The distinction between design and implementation of such interventions should be recognised.

Insufficient mixing of thawed serum samples leading to erroneous results - experience from a field study and use of a correction procedure.

Incorrect analysis results that are close to expected might not be recognized in scientific studies or routine patient care. In two field studies we obtained unexpected results in a large number of samples. The present study aimed to identify the source of error in the samples from these studies and to validate a method to obtain correct results. Pre-analytical procedures were scrutinized, giving no indications of inappropriate pre-analytical sample handling in the field or during transport in a tropical climate. Using a new set of samples from volunteers in simulation experiments, we observed the known concentration gradient of analytes sampled in gel as well as plain tubes after freezer storage and thawing. Experiments demonstrated that mixing of samples by vortexing alone was not sufficient to disrupt the gradient formed by freezing and thawing, which appeared to cause the problem encountered when we in field studies analyzed and biobanked large sample sets by robot pipetting. A correction procedure was introduced, in which the obtained value of an analyte was multiplied by a correction factor calculated for each sample using the expected sodium level (140 mmol/L) divided by the measured sodium value. When it was validated on results from the simulation experiments, we repeatedly found that the correction lead to results very close to true values for analytes of different size and charge. Usefulness of the procedure was demonstrated when applied to a large set of field study results.

Chronic kidney disease of non-traditional origin in Mesoamerica: a disease primarily driven by occupational heat stress.

The death toll of the epidemic of chronic kidney disease of nontraditional origin (CKDnt) in Mesoamerica runs into the tens of thousands, affecting mostly young men. There is no consensus on the etiology. Anecdotal evidence from the 1990s pointed to work in sugarcane; pesticides and heat stress were suspected. Subsequent population-based surveys supported an occupational origin with overall high male-female ratios in high-risk lowlands, but small sex differences within occupational categories, and low prevalence in non-workers. CKDnt was reported in sugarcane and other high-intensity agriculture, and in non-agricultural occupations with heavy manual labor in hot environments, but not among subsistence farmers. Recent studies with stronger designs have shown cross-shift changes in kidney function and hydration biomarkers and cross-harvest kidney function declines related to heat and workload. The implementation of a water-rest-shade intervention midharvest in El Salvador appeared to halt declining kidney function among cane cutters. In Nicaragua a water-rest-shade program appeared sufficient to prevent kidney damage among cane workers with low-moderate workload but not among cutters with heaviest workload. Studies on pesticides and infectious risk factors have been largely negative. Non-occupational risk factors do not explain the observed epidemiologic patterns. In conclusion, work is the main driver of the CKDnt epidemic in Mesoamerica, with occupational heat stress being the single uniting factor shown to lead to kidney dysfunction in affected populations. Sugarcane cutters with extreme heat stress could be viewed as a sentinel occupational population. Occupational heat stress prevention is critical, even more so in view of climate change.

La mortalidad por la epidemia de enfermedad renal crónica de origen no tradicional (ERCnt) en Mesoamérica asciende a decenas de miles de personas, principalmente hombres jóvenes. No existe consenso sobre su etiología. En la década de 1990, informes anecdóticos apuntaban como factor de riesgo al trabajo en plantaciones de caña de azúcar; se consideró como posibles causantes a los plaguicidas y el estrés térmico. Estudios de prevalencia de base poblacional subsiguientes apoyaron un origen ocupacional, con una proporción elevada de hombres respecto de las mujeres en las tierras bajas donde el riesgo era elevado, pero con pequeñas diferencias de sexo dentro de las categorías ocupacionales y baja prevalencia en el ámbito no laboral. Se reportó ERCnt en los trabajadores de la caña de azúcar y otros cultivos con alta exigencia física y en ocupaciones no agrícolas que implican trabajo manual intenso en ambientes calurosos, pero no entre los agricultores de subsistencia. Estudios recientes con diseños más sólidos han demostrado cambios en la función renal y en los biomarcadores de hidratación en el curso de los turnos laborales, y disminución de la función renal relacionada con el calor y la carga de trabajo en el curso de la cosecha. La implementación de una intervención basada en la provisión de agua, descanso y sombra a mitad de la cosecha en El Salvador detuvo la disminución de la función renal en los cortadores de caña. En Nicaragua, un programa de provisión de agua, descanso y sombra evitó la lesión renal en los trabajadores de la caña con una carga de trabajo baja y moderada, pero no entre los cortadores, quienes tienen la mayor carga de trabajo. Los estudios sobre plaguicidas y factores de riesgo infecciosos han sido en gran medida negativos. Los factores de riesgo no ocupacionales no explican los patrones epidemiológicos observados. En conclusión, el trabajo es el principal desencadenante de la epidemia de ERCnt en Mesoamérica, y el estrés térmico ocupacional es el único factor que consistentemente conduce a la disfunción renal en las poblaciones afectadas. Los cortadores que trabajan en los ingenios azucareros y están expuestos a un estrés térmico extremo podrían ser considerados una población ocupacional centinela. La prevención del estrés térmico ocupacional es crítica, más aún si se consideran los efectos del cambio climático.

A mortalidade devida à epidemia de doença renal crônica de origem não tradicional (DRCnt) na Mesoamérica atinge dezenas de milhares de pessoas, principalmente homens jovens. Não há consenso sobre a sua etiologia. Na década de 1990, informações empíricas apontavam o trabalho em plantações de cana de açúcar como um fator de risco; pesticidas e estresse térmico também eram considerados causas possíveis. As pesquisas populacionais subsequentes sustentam uma origem ocupacional da doença, com uma elevada proporção de homens quando comparados à de mulheres, em areas de baixa altitude, onde o risco da doença é mais elevado, mas com pequenas diferenças de gênero quando se consideram as categorias ocupacionais e baixa prevalência no ambiente não-ocupacional. A DRCnt foi identificada em trabalhadores agrícolas da cana de açúcar e de outras culturas que exigem trabalho físico de alta intensidade e em ocupações não agrícolas envolvendo um trabalho manual intenso em ambientes quentes, mas não entre os agricultores de subsistência. Estudos recentes com desenhos mais robustos demonstraram mudanças na função renal e nos biomarcadores de hidratação ao longo dos turnos de trabalho, e diminuição da função renal relacionada à exposição ao calor e à carga de trabalho ao longo da colheita. A implementação de uma intervenção de água-descanso-sombra durante a colheita em El Salvador interrompeu o declínio da função renal em cortadores de cana. Na Nicarágua, intervenções água-descanso-sombra parecem ter sido suficientes para evitar lesões renais em trabalhadores canavieiros com cargas de trabalho baixa e moderada, mas não entre os cortadores de cana que têm carga de trabalho mais pesada. Estudos sobre exposição a pesticidas e a fatores de risco de origem infecciosa têm sido largamente negativos. Os fatores de risco não-ocupacionais não explicam os padrões epidemiológicos observados. Em conclusão, ocupação é o principal desencadeador da epidemia de DRCnt na Mesoamérica, e o estresse térmico ocupacional é o único fator comprovado que leva à disfunção renal nas populações afetadas. Os cortadores de cana que trabalham em engenhos de açúcar e expostos a um estresse térmico extremo podem ser considerados uma população ocupacional sentinela. A prevenção do estresse térmico ocupacional é crítica, especialmente considerando os efeitos das mudanças climáticas.

Workload and cross-harvest kidney injury in a Nicaraguan sugarcane worker cohort.

OBJECTIVES: To examine the association between workload and kidney injury in a fieldworker cohort with different levels of physically demanding work over a sugarcane harvest, and to assess whether the existing heat prevention efforts at a leading occupational safety and health programme are sufficient to mitigate kidney injury. METHODS: Biological and questionnaire data were collected before (n=545) and at the end (n=427) of harvest among field support staff (low workload), drip irrigation workers (moderate), seed cutters (high) and burned sugarcane cutters (very high). Dropouts were contacted (87%) and reported the reason for leaving work. Cross-harvest incident kidney injury (IKI) was defined as serum creatinine increase ≥0.30 mg/dL or ≥1.5 times the baseline value, or among dropouts reporting kidney injury leading to leaving work. RESULTS: Mean cross-harvest estimated glomerular filtration rate change was significantly associated with workload, increasing from 0 mL/min/1.73 m2 in the low-moderate category to -5 mL/min/1.73 m2 in the high and -9 mL/min/1.73 m2 in the very high workload group. A similar pattern occurred with IKI, where low-moderate workload had 2% compared with 27% in the very high workload category. A healthy worker selection effect was detected, with 32% of dropouts reporting kidney injury. Fever and C reactive protein elevation were associated with kidney injury. CONCLUSIONS: Workers considered to have the highest workload had more cross-harvest kidney damage than workers with less workload. Work practices preventing heat stress should be strengthened and their role in preventing kidney damage examined further. Future occupational studies on chronic kidney disease of unknown aetiology should account for a healthy worker effect by pursuing those lost to follow-up.

Effect of an office ergonomic randomised controlled trial among workers with neck and upper extremity pain.

BACKGROUND: Office computer workers are at increased risk for neck/upper extremity (UE) musculoskeletal pain. METHODS: A seven-month office ergonomic intervention study evaluated the effect of two engineering controls plus training on neck/UE pain and mechanical exposures in 113 computer workers, including a 3-month follow-up period. Participants were randomised into an intervention group, who received a keyboard/mouse tray (KBT), touch pad (TP) for the non-dominant hand and keyboard shortcuts, and a control group who received keyboard shortcuts. Participants continued to have available a mouse at the dominant hand. Outcomes were pain severity, computer rapid upper limb assessment (RULA), and hand activity level. Prevalence ratios (PRs) evaluated intervention effects using dichotomised pain and exposure scores. RESULTS: In the intervention group, the dominnt proximal UE pain PR=0.9, 95% CI 0.7 to 1.2 and the dominant distal UE PR=0.8, 95% CI 0.5 to 1.3, postintervention. The non-dominant proximal UE pain PR=1.0, 95% CI 0.8 to 1.4, while the non-dominant distal UE PR=1.2, 95% CI 0.6 to 2.2, postintervention. Decreases in non-neutral postures were found in two RULA elements (non-dominant UE PR=0.9, 95% CI 0.8 to 0.9 and full non-dominant RULA PR=0.8, 95% CI 0.8 to 0.9) of the intervention group. Hand activity increased on the non-dominant side (PR=1.4, 95% CI 1.2 to 1.6) in this group. CONCLUSIONS: While the intervention reduced non-neutral postures in the non-dominant UE, it increased hand activity in the distal region of this extremity. To achieve lower hand activity, a KBT and TP used in the non-dominant hand may not be the best devices to use.

Resolving the enigma of the mesoamerican nephropathy: a research workshop summary.

The First International Research Workshop on Mesoamerican Nephropathy (MeN) met in Costa Rica in November 2012 to discuss how to establish the extent and degree of MeN, examine relevant causal hypotheses, and focus efforts to control or eliminate the disease burden. MeN describes a devastating epidemic of chronic kidney disease of unknown origin predominantly observed among young male sugarcane cutters. The cause of MeN remains uncertain; however, the strongest hypothesis pursued to date is repeated episodes of occupational heat stress and water and solute loss, probably in combination with other potential risk factor(s), such as nonsteroidal anti-inflammatory drug and other nephrotoxic medication use, inorganic arsenic, leptospirosis, or pesticides. At the research workshop, clinical and epidemiologic case definitions were proposed in order to facilitate both public health and research efforts. Recommendations emanating from the workshop included measuring workload, heat, and water and solute loss among workers; quantifying nephrotoxic agents in drinking water and food; using biomarkers of early kidney injury to explore potential causes of MeN; and characterizing social and working conditions together with methods for valid data collection of exposures and personal risk factors. Advantages and disadvantages of different population study designs were detailed. To elucidate the etiology of MeN, multicountry studies with prospective cohort design, preferably integrating an ecosystem health approach, were considered the most promising. In addition, genetic, experimental, and mechanistic methods and designs were addressed, specifically the need for kidney biopsy analysis, studies in animal models, advances in biomarkers, genetic and epigenetic studies, a common registry and repository of biological and demographic data and/or specimens, and other areas of potential chronic kidney disease experimental research. Finally, in order to improve international collaboration on MeN, workshop participants agreed to establish a research consortium to link these Mesoamerican efforts to other efforts worldwide.

Association Between Acute Kidney Injury Hospital Visits and Environmental Heat Stress at a Nicaraguan Sugarcane Plantation.

BACKGROUND: Mesoamerican sugarcane cutters are at a high risk of chronic kidney disease of non-traditional origin, a disease likely linked to heat-related acute kidney injury (AKI). Studies in general populations have described a positive association between high environmental temperatures and clinically assessed kidney outcomes, but there are no studies in occupational settings. METHOD: We accessed routine records of clinically diagnosed AKI (AKI-CD) and wet bulb globe temperatures (WBGT) at a large Nicaraguan sugarcane plantation and modeled the relationship between these using negative binomial regression. A rest-shade-hydration intervention was gradually enhanced during the study period, and efforts were made to increase the referral of workers with suspected AKI to healthcare. RESULTS: Each 1°C WBGT was associated with an 18% (95% confidence interval [CI]: [4, 33%]) higher AKI-CD rate on the same day and a 14% (95% CI [-5, 37%]) higher rate over a week. AKI-CD rates and severity, and time between symptoms onset and diagnosis decreased during the study period, that is, with increasing rest-shade-hydration intervention. Symptoms and biochemical signs of systemic inflammation were common among AKI-CD cases. DISCUSSION: Occupational heat stress, resulting from heavy work in environmental heat, was associated with a higher rate of clinically diagnosed AKI in a population at risk of CKDnt. Promoting rest-shade-hydration may have contributed to reducing AKI rates during the study period. Occupational health and safety personnel have key roles to play in enforcing rest, shade, and hydration practices, referring workers with suspected AKI to healthcare as well as collecting and analyzing the data needed to support workplace heat stress interventions.

Impact of heat and a rest-shade-hydration intervention program on productivity of piece-paid industrial agricultural workers at risk of chronic kidney disease of nontraditional origin.

OBJECTIVES: Assess the impact of environmental heat and a rest-shade-hydration (RSH) intervention against heat stress on productivity of piece-paid Mesoamerican sugarcane cutters. These workers are at a high risk of chronic kidney disease of non-traditional origin (CKDnt), from the severe heat stress they experience due to heavy work under hot conditions. RSH interventions in these populations improve kidney health outcomes, but their impact on productivity has yet to be examined. METHODS: We accessed routine productivity data from seed (SC, N = 749) and burned (BCC, N = 535) sugarcane cutters observed over five harvest seasons with increasing RSH intervention at a large Nicaraguan sugarcane mill. Hourly field-site wet-bulb globe temperature (WBGT) was recorded by mill staff and summarized as a daily mean. Mixed linear regression was used to model daily productivity, adjusting for age (18-29, 30-44, and >45 years), sex, WBGT (<28, 28-29, 29-30, 30-31, and >31 °C) on the same and preceding day, harvest season (2017-18 to 2021-22), month, and acclimatization status (<1, 1-2, and >2 weeks). RESULTS: There was an inverse dose-response relationship between SC productivity and WBGT on the same and preceding days, decreasing by approximately 3%/°C WBGT. Productivity increased during the study period, i.e. coinciding with RSH scale-up, by approximately 19% in SC and 9% in BCC. CONCLUSION: Agricultural worker productivity was expected lower on hotter days, strengthening the interest in all stakeholders to mitigate increasing global temperatures and their impact. Despite decreasing the total time allocated for work each day, an RSH intervention appears to result in increased productivity and no apparent loss in productivity.

Can psychosocial risk factors mediate the association between precarious employment and mental health problems in Sweden? Results from a register-based study.

OBJECTIVES: The aim of this study was to examine the mediating effect of the psychosocial work environment on the association between precarious employment (PE) and increased risk of common mental disorders (CMD), substance use disorders and suicide attempts. METHODS: This longitudinal register-study was based on the working population of Sweden, aged 25-60 years in 2005 (N=2 552 589). Mediation analyses based on a decomposition of counterfactual effects were used to estimate the indirect effect of psychosocial risk factors (PRF) (mediators, measured in 2005) on the association between PE (exposure, measured in 2005) and the first diagnosis of CMD, substance use disorders, and suicide attempts occurring over 2006-2017. RESULTS: The decomposition of effects showed that the indirect effect of the PRF is practically null for the three outcomes considered, among both sexes. PE increased the odds of being diagnosed with CMD, substance use disorders, and suicide attempts, among both men and women. After adjusting for PE, low job control increased the odds of all three outcomes among both sexes, while high job demands decreased the odds of CMD among women. High job strain increased the odds of CMD and suicide attempts among men, while passive job increased the odds of all three outcomes among women. CONCLUSION: The results of this study did not provide evidence for the hypothesis that psychosocial risks could be the pathways linking precarious employment with workers` mental health. Future studies in different social contexts and labour markets are needed.

Work-related injury surveillance in Vietnam: a national reporting system model.

Developing nations bear a substantial portion of the global burden of injury. Public health surveillance models in developing countries should recognize injury risks for all levels of society and all causes and should incorporate various groups of workers and industries, including subsistence agriculture. However, many developing nations do not have an injury registration system; current data collection methods result in gross national undercounts of injuries, failing to distinguish injuries that occur during work. In 2006, we established an active surveillance system in Vietnam's Xuan Tien commune and investigated potential methods for surveillance of work-related injuries. On the basis of our findings, we recommend a national model for work-related injury surveillance in Vietnam that builds on the existing health surveillance system.

Increase of chronic low back pain prevalence in a medium-sized city of southern Brazil.

BACKGROUND: Chronic low back pain (CLBP) is a highly disabling morbidity with high social, economic and individual effects. Demographic, occupational and behavioral changes that took place in Brazil over the last decade are related with an increasing burden of chronic conditions. Despite these changes, comparison studies on CLBP prevalence and associated factors, over time are scarce in the literature in general, and unknown in Brazil. The present study compared the CLBP prevalence in a medium sized city in Brazil between the years 2002 and 2010 and examined factors associated with prevalence in 2010. METHODS: Two cross-sectional studies with similar methodology were conducted in a medium-sized city in southern Brazil, in 2002 and 2010. 3182 individuals were interviewed in the first study and 2732 in the second one, all adults aged twenty years or more. Those who reported pain for seven weeks or more in the last three months in the lumbar region where considered cases of CLBP. RESULTS: The CLBP prevalence increased from 4.2% to 9.6% in 8 years. In most of the studied subgroups the CLBP prevalence has at least doubled and the increase was even larger among younger individuals with more years of education and higher economic status. CONCLUSIONS: Increase in CLBP prevalence is worrisome because it is a condition responsible for substantial social impact, besides being an important source of demand for health services.