La salud humana frente al estrés térmico por el cambio climático

Introducción: La alteración del clima planetario, atribuida directa o indirectamente a la actividad humana, que modifica la composición de la atmósfera mundial y se suma a la variabilidad natural del clima, es conocida como cambio climático global. Sus efectos en la salud, directos e indirectos, ya presentes, perturbarán a la mayoría de las poblaciones en las próximas décadas y pondrán en riesgo la vida y el bienestar de miles de millones de personas. Objetivo: Describir, a partir de una revisión, los principales riesgos para la salud humana derivados de la mayor frecuencia e intensidad de episodios de estrés térmico derivados del cambio climático. Métodos: Se realizó una revisión bibliográfica relativa a los efectos de la temperatura sobre la salud humana, así como su influencia sobre la mortalidad general, en el periodo 2008 hasta 2021, en las bases de datos Scopus, PubMed/Medline, SciELO, Ebsco, LiLACS, así como, otras fuentes y recursos de información disponibles en Internet. Se utilizó el vocabulario controlado del Descriptor en Ciencias de la Salud. Resultados: Se recuperaron 32 publicaciones sobre de la influencia del clima y sus cambios en la salud humana que plantearon, por lo general, que las altas temperaturas guardaron relación con el incremento de la mortalidad principalmente por enfermedades cardiovasculares, cerebrovasculares y respiratorias, se han convertido en un contribuyente considerable a la carga de morbilidad. Conclusiones: Las temperaturas extremas incrementan la morbilidad y mortalidad agudas, principalmente en grupos de riesgo. La promoción de una adecuada hidratación y el uso de ropas adecuadas, ayudará a las personas en la prevención de afecciones por las temperaturas extremas, erigiéndose en acciones individuales de protección contra los efectos de la mayor frecuencia e intensidad de eventos de estrés térmico asociado al cambio climático, a incorporar a la cotidianidad.

Introduction: The alteration of the planetary climate, attributed directly or indirectly to human activity, which modifies the composition of the world atmosphere and adds to the natural variability of the climate, is known as global climate change. Its direct and indirect health effects, already present, will disturb most populations in the coming decades and put the lives and well-being of billions of people at risk. Objective: To describe, based on a review, the main risks to human health derived from the greater frequency and intensity of episodes of thermal stress derived from climate change. Methods: A bibliographic review was carried out regarding the effects of temperature on human health, as well as its influence on general mortality, in the period 2008 to 2021, in the Scopus, PubMed/Medline, SciELO, Ebsco, LiLACS, as well as other information sources and resources available on the Internet. The controlled vocabulary descriptors in Health Sciences were used. Results: 32 publications on the influence of climate and its changes on human health were recovered, which generally stated that high temperatures were related to the increase in mortality, mainly due to cardiovascular, cerebrovascular and respiratory diseases, and have become a significant contributor to the burden of disease. Conclusions: Extreme temperatures increase acute morbidity and mortality, mainly in risk groups. The promotion of adequate hydration and the use of adequate clothing will help people in the prevention of conditions caused by extreme temperatures, establishing individual actions to protect against the effects of the greater frequency and intensity of heat stress events associated with climate change, to incorporate into daily life.

Research progress in mechanism and protection of high temperature environment influencing the body function / 中华创伤杂志

The thermal environment increases the risk of thermal injury for persons under high temperature environment. A full understanding of the effects and hazards of the thermal environment on the human body is of great significance to improve the awareness of persons under high temperature environment and reduce occupational heat damage during work. The authors mainly review the thermal environment from aspects of the definition, mechanism of its influence on main functional systems of the human body, influencing factors of heat stress and progress of protection, so as to provide references for the identification and protection of heat-induced diseases for workers under high temperature environment.

Estresse por calor na Atenção Primária à Saúde: uma revisão clínica / Heat stress in Primary Health Care: A clinical review / Estrés por calor en la Atención Primaria a la Salud: una revisión clínica

Introdução: A exposição nociva ao calor ganha mais relevância com a progressão do aquecimento global antropogênico e a Atenção Primária à Saúde (APS) tem um papel crescente nesse cenário. No Brasil, as ondas de calor entre 2014 e 2015 duraram mais tempo que nos anos prévios, além disso, entre 2000-2015 a associação entre temperatura e hospitalizações variou de acordo com a duração da exposição ao calor. Nesse contexto, o objetivo desta revisão é realizar uma atualização sobre manejo clínico de patologias relacionadas ao calor na APS. Metodologia: Realizou-se a busca na base de dados ACCESSS, que utiliza a pirâmide 5.0 da assistência à saúde baseada em evidências. Foram identificados 103 sumários sintetizados para referência clínica com as palavras "Heat stress", "Heat Stroke", "Heat Wave" e "Heat Exhaustion", mas apenas três entravam no escopo deste estudo. Resultados e Discussão: O estresse pelo calor é uma condição comum, negligenciada e evitável que afeta diversos pacientes, iniciando-se com uma má adaptação ao calor que se não for corrigida pode gerar uma cascata de eventos inflamatórios. O estresse pelo calor é caracterizado por sintomas inespecíficos, como mal-estar, cefaleia e náusea. O tratamento envolve o resfriamento do paciente e monitoramento, garantindo hidratação adequada. A exaustão pelo calor, se não tratada, pode evoluir para insolação, uma doença grave que pode levar ao coma e morte, envolvendo disfunção do sistema nervoso central - necessitando de um tratamento mais agressivo além do resfriamento

Introduction: The nocive exposure to heat gets more attention with anthropogenic global warming, and Primary Health Care (PHC) has a growing role in this scenario. In Brazil heat waves between 2014 and 2015 lasted longer than in previous years. Further, in addition between 2000-2015 the association between temperature and hospitalizations varied according to the duration of heat exposure. Therefore, the aim of this review is to perform an update on clinical management of heat related pathologies in PHC. Methodology: The ACCESSS database was searched using the evidence-based health care pyramid 5.0, where we identified 103 synthesized summaries for clinical reference with words "Heat stress", "Heat Stroke", "Heat Wave" and "Heat Exhaustion", but only three fell within the scope of this study. Results and Discussion: Heat stress is a common, neglected and preventable condition that affects several patients, it starts with a poor adaptation to heat that if it is not adjusted it can generate a cascade of inflammatory events. Heat stress is characterized by nonspecific symptoms such as malaise, headache and nausea. The treatment involves patient monitoring and cooling, ensuring adequate hydration. Heat exhaustion, if untreated, can progress to heatstroke, a serious illness that can lead to coma and death, involving central nervous system dysfunction - requiring more aggressive treatment than cooling.

Introducción: La exposición nociva al calor gana más destaque con la progresión del calentamiento global antropogénico, y la Atención Primaria a la Salud tienen un papiel cresciente en este escenario. En Brasil las olas de calor entre 2014 y 2015 duraron más tiempo que en los años previos, además entre 2000-2015 la asociación entre temperatura y hospitalizaciones ha variado de acuerdo con la duración de la exposición al calor. En este contexto, el objetivo de esta revisión es realizar una actualización sobre manejo clínico de patologías relacionadas al calor en la APS. Metodología: Se realizó la búsqueda en la base de datos ACCESSS, que utiliza la pirámide 5.0 de la asistencia a la salud basada en evidencias. Se han identificado 103 sumarios sintetizados para referencia clínica con las palabras "Heat stress", "Heat Stroke", "Heat Wave" y "Heat Exhaustion", pero sólo tres son considerados en el ámbito de este estudio. Resultados y Discusión: El estrés por el calor es una condición común, descuidada y evitable que afecta a varios pacientes, iniciándose con una mala adaptación al calor que si no se corrige puede generar una cascada de eventos inflamatorios. El estrés por el calor se caracteriza por síntomas inespecíficos, como malestar, cefalea y náuseas. El tratamiento implica el enfriamiento del paciente y el monitoreo, garantizando la hidratación adecuada. El agotamiento por el calor, si no se trata, puede evolucionar hacia la insolación, una enfermedad grave que puede llevar al coma y a la muerte, involucrando disfunción del sistema nervioso central - necesitando un tratamiento más agresivo además del enfriamiento.

Risco de exposição à sobrecarga térmica para trabalhadores da cultura de cana-de-açúcar no Estado de São Paulo, Brasil / Risk of exposure to heatstroke in sugarcane workers in São Paulo State, Brazil / Riesgo de exposición a la sobrecarga térmica para trabajadores de plantaciones de caña de azúcar en el estado de São Paulo, Brasil

Resumo: O calor ambiental é um agravante às atividades dos trabalhadores da cultura de cana-de-açúcar, sendo o corte manual uma das atividades pesadas que favorece a elevada geração de calor metabólico. Isso associado com outras condições precárias de trabalho favorece o estresse térmico, podendo provocar graves doenças ou até levar à morte. O objetivo deste estudo é quantificar o risco de sobrecarga térmica que os cortadores de cana-de-açúcar de São Paulo, Brasil, são expostos. Por meio de metodologia específica, foram utilizados quatro anos de dados para estimar o Índice de Bulbo Úmido - Termômetro de Globo sob a consideração das atividades leve, moderada e pesada. Os resultados mostram extrapolação do limite legal de exposição para atividade contínua em períodos de 1 a 8 horas, o que requer medidas de controle para continuidade do trabalho. A principal constatação é a observância do risco de sobrecarga térmica para os três tipos de atividade: leve, moderada e pesada. Os limites de tolerância são ultrapassados durante todo o turno de trabalho em cerca de 7% dos dias, para atividade pesada, e em cerca de 3%, para atividade moderada. Além disso, percebeu-se que as áreas com maior risco de sobrecarga térmica são as mesmas onde há predominância da cultura de cana-de-açúcar.

Abstract: Environmental heat is an aggravating factor for sugarcane workers, and manual cane cutting is one of the heavy work activities that favor the generation of metabolic heat. This can combine with other precarious working conditions to produce heatstroke, potentially leading to serious complications and even death. The study aimed to quantify the risk of overheating in sugarcane cutters in São Paulo, Brazil. Drawing on a specific methodology, the study used four years of data to estimate the Globe Thermometer Wet Bulb Index based on light, moderate, and heavy activities. The results showed that the legal limit was exceeded for continuous activity in periods from 1 to 8 hours, which requires control measures in order to continue working. The principal observation was the risk of heatstroke in the three types of activity: light, moderate, and heavy. The limits were exceeded throughout the work shift on 7% of the days for heavy activity and on 3% of the days for moderate activity. In addition, the areas with the highest risk of heatstroke coincide with predominant cane-growing.

Resumen: El calor ambiental es un agravante para las actividades de los trabajadores de plantaciones de caña de azúcar, siendo el corte manual una de las actividades pesadas que favorece la elevada generación de calor metabólico. Esto, asociado con otras condiciones precarias de trabajo, favorece el estrés térmico, pudiendo provocar graves enfermedades o incluso llevar a la muerte. El objetivo de este estudio es cuantificar el riesgo de sobrecarga térmica a la que los cortadores de caña de azúcar de São Paulo, Brasil, están expuestos. Mediante una metodología específica, se utilizaron cuatro años de datos para estimar el Índice de Bulbo Húmedo-Termómetro de Globo, considerando a las actividades como: leves, moderadas y pesadas. Los resultados muestran la extrapolación del límite legal de exposición para la actividad continua en períodos de 1 a 8 horas, lo que requiere medidas de control para la continuidad del trabajo. La principal constatación es la observancia del riesgo de sobrecarga térmica para los tres tipos de actividad: leve, moderada y pesada. Los límites de tolerancia se sobrepasan durante todo el turno de trabajo en cerca de un 7% dos días, en el caso de la actividad pesada, y en cerca de un 3% en la actividad moderada. Además, se percibió que las áreas con mayor riesgo de sobrecarga térmica son las mismas donde hay predominancia de plantaciones de caña de azúcar.

Impact thermal environment of armored vehicle cabin on humans / 军事医学

Objective To prolong the working time of the crew under a high temperature and high humidity environment in armored vehicles , improve work efficiency , and to prevent excessive heat load from doing any harm to the human body . Methods The man-machine environment was analyzed , the corresponding environment and the conditions aboard were further quantitatively studied , and man-machine-environment interactions were analyzed .Also,a questionnaire survey was conducted at the same time .Results and Conclusion The thermal equilibrium and thermal comfort calculation program were compiled and validated through the questionnaire survey in order to provide support for environment assessment and protection design .

Apoptosis in response to heat stress is positively associated with heat-shock protein 90 expression in chicken myocardial cells in vitro

To determine heat-shock protein (Hsp)90 expression is connected with cellular apoptotic response to heat stress and its mechanism, chicken (Gallus gallus) primary myocardial cells were treated with the Hsp90 promoter, aspirin, and its inhibitor, geldanamycin (GA), before heat stress. Cellular viability, heat-stressed apoptosis and reactive oxygen species level under different treatments were measured, and the expression of key proteins of the signaling pathway related to Hsp90 and their colocalization with Hsp90 were detected. The results showed that aspirin treatment increased the expression of protein kinase B (Akt), the signal transducer and activator of transcription (STAT)-3 and p-IKKα/β and the colocalization of Akt and STAT-3 with Hsp90 during heat stress, which was accompanied by improved viability and low apoptosis. GA significantly inhibited Akt expression and p-IKKα/β level, but not STAT-3 quantity, while the colocalization of Akt and STAT-3 with Hsp90 was weakened, followed by lower cell viability and higher apoptosis. Aspirin after GA treatment partially improved the stress response and apoptosis rate of tested cells caused by the recovery of Akt expression and colocalization, rather than the level of STAT-3 (including its co-localization with Hsp90) and p-IKKα/β. Therefore, Hsp90 expression has a positive effect on cellular capacity to resist heat-stressed injury and apoptosis. Moreover, inhibition of Hsp90 before stress partially attenuated its positive effects.

Estratégias para minimizar os efeitos de um ambiente térmico adverso para frangos de corte / Strategies to minimize the adverse thermal environment in broiler chickens

O calor limita a produção de frangos de corte. Este trabalho avaliou as interações entre o termocondicionamento precoce (TCP) e o uso do equilíbrio eletrolítico (EE) sobre o desempenho e as características da carcaça das aves. Assim, o balanço eletrolítico (BE = Na + K - Cl) foi ajustado em 350mEq/kg, e a relação eletrolítica (K+Cl)/Na em 3:1, pelo programa PPFR. O experimento foi realizado no setor de Zootecnia da Faculdade de Medicina Veterinária de Araçatuba/Unesp. Alojaram-se 240 pintos machos de um dia de idade, linhagem Cobb-500(r), em bateria metálica com 24 divisões e aquecimento elétrico automático. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial 2x2, totalizando quatro tratamentos com seis repetições e 10 aves por parcela experimental. O TCP ocorreu no quinto dia de idade, por 24 horas, a 36,5°C, em metade do lote. Posteriormente, as aves foram transferidas para um galpão climatizado e alojadas em boxes, da mesma forma que a outra parcela que não passou pelo TCP. Avaliaram-se os efeitos do estresse calórico crônico (seis horas a 32°C) aplicado do 35º ao 39º dia de idade. Foram monitoradas a temperatura e a umidade do ar, bem como a temperatura de globo negro. Alimentação e água foram fornecidas ad libitum. Calcularam-se os dados de desempenho zootécnico e a taxa de mortalidade das aves. Submeteram-se os resultados à análise de variância e à comparação de médias pelo teste de Tukey. Não houve interação entre o TCP e o EE sobre o desempenho e as características da carcaça das aves. As estratégias, TCP e EE, mostraram-se ineficazes para amenizar os efeitos do estresse calórico crônico em frangos de corte.

Heat limits the production of broilers. This study evaluated the interactions between early thermal conditioning (ETC) and the electrolyte balance (EB) on performance and characteristics of birds' carcass. Thus, the electrolyte balance (BE = Na+ + K+ - Cl-), was set to 350mEq/kg and electrolyte ratio (K+ + Cl-)/ Na+ in 3:1 by the PPFR program. The experiment was carried out at the Animal Science department of the Faculty of Veterinary Medicine of Araçatuba / UNESP. 240 1 day old Cobb-500(r) male chicks were used, lodged in metal batteries with 24 divisions and automatic electric heating. The experimental design was completely randomized in a 2x2 factorial arrangement, totaling 4 treatments with 6 replicates and 10 birds per experimental plot. ETC occurred on the 5th day of age for 24 hours at 36.5°C in half of the batch. Subsequently, these birds were transferred to an environmentally controlled shed and were grown in boxes, in the same way as the other half that had not received ETC treatment. The effects of chronic heat stress (6 hours at 32°C) applied from the 35th through the 39th day of age were evaluated. Temperature and air humidity, as well black-globe temperature were monitored electronically. Food and water were provided ad libitum. The growth performance data and the mortality rate of birds were measured. The results were subjected to analysis of variance and comparison of means was done by Tukey test. There were no interaction effects between ETC and EB on performance and characteristics of birds' carcass. The ETC and EB strategies proved to be ineffective to mitigate the effects of chronic heat stress in broilers.

Estado de hidratação de atletas em corrida de rua de 15 km sob elevado estresse térmico / Hydration status in athletes on 15 km street race under elevated heat stress / Estado de hidratación de atletas en carrera de calle de 15 km bajo elevado estrés térmico

INTRODUÇÃO: Um adequado estado de hidratação é de suma importância para os participantes de corridas de rua, tanto para um melhor desempenho esportivo, quanto na prevenção dos distúrbios causados pelo calor. OBJETIVO: O estudo visa avaliar o estado de hidratação de indivíduos do sexo masculino em corrida de rua de 15 km. MÉTODOS: A amostra foi composta por 15 indivíduos do sexo masculino (37,67±7,22 anos) praticantes habituais de corrida de rua. O estado de hidratação foi avaliado antes e após a corrida através dos seguintes parâmetros: peso corporal, coloração e gravidade específica da urina (GEU), análise da impedância bioelétrica (BIA), níveis de hemoglobina (Hb) e hematócrito (Ht). Na análise dos dados, foi utilizado o teste t de Student pareado ou o teste de Wilcoxon, aceitando-se como estatisticamente significante p < 0,01. RESULTADOS: Houve diminuição do peso corporal dos indivíduos após a corrida (p<0,0001), assim como elevação dos níveis de Hb e Ht. Apesar da diminuição observada na GEU após o exercício, não houve melhora significativa do padrão de coloração da urina ou diferença entre o conteúdo inicial e final de água corporal total. A temperatura ambiente (TA) e umidade relativa do ar (URA) foram de 38,75±1,79°C e 37,37±4,66%, respectivamente. CONCLUSÃO: O exercício no ambiente em questão conduziu os indivíduos a um estado de desidratação, apenas detectado pela análise da variação do peso corporal e de parâmetros sanguíneos através dos níveis de Hb e Ht. Parâmetros urinários como a coloração da urina e GEU, assim como aqueles obtidos através da BIA, provavelmente foram confundidos por variáveis não controladas pelo presente estudo. .

INTRODUCTION: An adequate hydration status is of utmost importance to participants of street running, both for better sports performance and to preventi disorders caused by heat. OBJECTIVE: The study aimed to evaluate the hydration status of males on a 15 km street race. METHODS: The sample consisted of 15 males (37.67 ± 7.22 years old) habitual street runners. The hydration status was evaluated before and after the race by the following parameters: body weight, color and urine specific gravity (USG), bioelectrical impedance analysis (BIA), hemoglobin (Hb) and hematocrit (Ht). In data analysis, the paired Student t-test or the Wilcoxon test were used, setting as statistically significant p <0.01. RESULTS: There was a decrease in body weight of the subjects after the race (p <0.0001), as well as an increase in Hb and Ht. Despite the observed decrease in USG after exercise, there was no significant improvement in the standard of urine color or difference between the initial and final contents of total body water. The room temperature (RT) and relative humidity (RH) were 38.75±1.79°C and 37.37±4.66%, respectively. CONCLUSION: The exercise in the environment at issue led the individuals to a state of dehydration, only detected by the analysis of variation in body weight and blood parameters such as Hb and Ht. Urinary parameters such as urine color and USG, as well as those obtained by BIA, were probably confused by variables that were not controlled by the present study. .

INTRODUCCIÓN: Un adecuado estado de hidratación es de suma importancia para los participantes de las carreras de calle, tanto para un mejor desempeño deportivo, como en la prevención de los disturbios causados por el calor. OBJETIVO: El estudio pretende evaluar el estado de hidratación de individuos del sexo masculino en carrera de calle de 15 km. MÉTODOS: La muestra fue compuesta por 15 individuos masculinos (37,67 ± 7,22 años) practicantes habituales de carreras de calle. El estado de hidratación fue evaluado antes y después de la carrera a través de los siguientes parámetros: peso corporal, coloración y gravedad específica de la orina (GEO), análisis de la impedancia bioeléctrica (BIA), niveles de hemoglobina (Hb) y hematocrito (Ht). En el análisis de los datos, fue utilizado el test t de Student emparejado o el test de Wilcoxon, aceptándose como estadísticamente significativo p <0,01. RESULTADOS: Hubo disminución del peso corporal de los individuos después de la carrera (p <0,0001), así como aumento de los niveles de Hb y Ht. A pesar de la disminución observada en la GEO después del ejercicio, no hubo una mejora significativa del patrón de coloración de la orina o diferencia entre el contenido inicial y final de agua corporal total. La temperatura ambiente (TA) y la humedad relativa del aire (HRA) fueron de 38,75 ± 1,79 y 37,37°C ± 4,66%, respectivamente. CONCLUSIÓN: El ejercicio en el ambiente en cuestión llevó a los individuos a un estado de deshidratación, solamente detectado mediante el análisis de la variación del peso corporal y de parámetros sanguíneos como los niveles de Hb y Ht. Parámetros urinarios como coloración de la orina y GEO, así como aquellos obtenidos mediante BIA, probablemente fueron confundidos por variables no controladas en este estudio. .

Effects of ulinastatin on oxidative stress and renal injury in rats with severe heatstroke / 解放军医学杂志

Objective To study the effects of ulinastatin on oxidative stress factors and renal function in rats with severe heatstroke. Methods-Forty-two male SPF Wistar rats were randomly divided into normal control group (group C, n=6), heat stroke group (HS group, n=18) and ulinastatin treatment group (UTI group, n=18). Rats in the HS group and UT group were placed in an artificial climate chamber to induce HS, while rats of group C were kept at room temperature (23±0.2°C). UT rats were given by intraperitoneal injection of ulinastatin before model reproduction in a dose of 100 thousand units/kg, and it was repeated every 12h. The other in the rest two groups were injected with equal amount of normal saline. All the rats were sacrificed in batches at 0, 6 and 24h after successful modeling. Before death, blood samples were collected to determine serum creatinine and urea nitrogen with automatic biochemical analyzer. Meanwhile the concentrations of renal superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) were determined with colorimetric method. Pathological changes in renal tissue of all animals were observed at 24h after model replication with light and electron microscopy. Results-Compared with rats in group C, the MDA levels at 0h after onset of heatstroke increased significantly (P0.05). At the same time, compared with HS group, the elevated levels of serum Cr and BUN in the UTI group were lower at 6 and 24h after heatstroke onset (all P<0.05). The pathological damage of the kidney at 24h after heatstroke was significantly ameliorated in the UTI group. Conclusions-Oxidative stress is involved in the pathogenesis of the renal injury during heatstroke, UTI may protect rats with heatstroke from renal injury by inhibiting oxidative stress in the kidney.

Impacto do estresse na saúde de cortadores de cana / The impact of stress on the health of sugar cane cutters

OBJETIVO Analisar os níveis de estresse e a prevalência de sintomas físicos e psíquicos em trabalhadores do corte de cana antes e depois da safra. MÉTODOS Foram estudados 114 cortadores de cana, 109 trabalhadores urbanos na pré-safra, 102 cortadores de cana e 81 trabalhadores urbanos na pós-safra, na cidade de Mendonça, SP, em 2009. A análise dos dados baseou-se na frequência e porcentagem dos avaliados com sintomas de estresse, tendo sido utilizado o Inventário de Sintomas de Estresse para Adultos de Lipp-ISSL. Os dados gerais coletados foram analisados segundo estatística descritiva. Utilizou-se o teste Exato de Fisher para comparar a variável categórica representada pelo estresse pré e pós-safra nos grupos cortadores de cana e trabalhadores urbanos. Foram considerados significativos os valores de p menor que 0,05. RESULTADOS O estresse aumentou nos cortadores de cana após a safra (34,2% na pré-safra e 46,1% na pós-safra); nos trabalhadores urbanos, o estresse diminuiu de 44,0% na pré-safra para 42,0% na pós-safra. Houve predominância da fase de resistência do estresse para ambos os grupos, com sinais mais evidentes da fase de quase-exaustão e de exaustão para os cortadores de cana. Após a safra, houve tendência a aumentar o número de cortadores de cana com sintomas de quase-exaustão (6,4%) e exaustão (10,6%), bem como aumento na proporção de cortadores de cana com sintomas físicos (de 20,5% para 25,5%) e psicológicos (de 64,1% para 70,2%). Para os dois grupos, os sintomas psicológicos foram elevados nas duas fases (70,2% e 64,7%, respectivamente). CONCLUSÕES O processo produtivo de trabalho do cortador de cana pode provocar estresse. Fatores individuais, como a percepção cognitiva da experiência, crenças de autoeficácia e expectativas ...

OBJECTIVE Evaluate the impact of stress on sugar cane cutters and the prevalence of physical and psychological symptoms before and after harvest. METHODS We studied 114 sugarcane cutters and 109 urban workers in the pre-harvest and 102 sugar cane cutters and 81 urban workers in the post-harvest period in the city of Mendonça, SP, Southeastern Brazil, in 2009. Data analysis was based on the frequency and percentage of the assessed symptoms of stress, using the Lipp-ISSL test (Symptoms of Stress for Adults). The data were analyzed using descriptive statistics. The Fisher Test was used to compare the variable of stress between pre- and post-harvest within the sugar cane cutter and urban worker groups. P values below 0.05 were considered significant. RESULTS Stress in sugar cane cutters increased after harvesting (34.2% pre-harvest and 46.1% post-harvest); in urban workers, stress decreased from 44.0% pre-harvest to 42.0% post-harvest. There was prevalence of the phase of resistance to stress for both groups with signs more apparent from the near-exhaustion and exhaustion phases for sugar cane cutters. After harvest, there was a tendency for the number of sugar cane cutters with symptoms of near-exhaustion (6.4%) and exhaustion (10.6%) to increase. After harvest there was a trend for the number of sugar cane cutters with physical symptoms (pre-harvest = 20.5%, post-harvest = 25.5%) and psychological symptoms (pre-harvest = 64.1%; post-harvest = 70.2%) to increase. For both groups, predominantly psychological symptoms occurred in both phases (70.2% versus 64.7%). CONCLUSIONS The work process of cutting cane can cause stress. Individual factors such as cognitive perception of the experience, self-efficacy beliefs and expectations of the employee regarding their performance can influence the understanding of the reactions in their body in face of the work. .

Changes in mesenteric lymph microcirculation in rats suffering from severe heatstroke / 解放军医学杂志

Objective To observe the dynamic changes in mesenteric lymph microcirculation and its kinetics in rats suffering from severe heatstroke (SHS), and to explore the role of mesenteric lymph in the pathogenesis of SHS. Methods SHS rat models were reproduced in an incubator with high temperature and high humidity. The vital signs and the time of onset of SHS in rats were recorded continuously during the process of heat stress. Parameters of mesenteric lymph microcirculation including Index-I, Index-II, L.D-Index, and intra-lymphatic pressure before heat exposure, 60min after heat exposure, and onset of SHS were collected and analyzed. Mesenteric lymph was collected at 30-min interval, and its volume of production was measured dynamically. Results Rat SHS model was reproduced successfully. After exposure to the environment with high temperature and high humidity, the core temperatures of the rats raised to 42°C at the time point of 60min, and HS onset occurred at about 77min. Mesenteric lymph-vessel contraction indices including Index-I, Index-II, L.D-Index, lymph-vessel pressure and mesenteric lymph flow decreased significantly at the time point of 60min (P<0.05). However, all the above parameters increased at the time point of SHS onset (P<0.05), but had not yet reached the normal levels before hyperthermia and high humidity exposure (P<0.05). Conclusion Changes of mesenteric lymph microcirculation in rats with SHS shows a dynamical regularity, which may take part in the pathogenesis of SHS.

The Effects of Temperature on Heat-related Illness According to the Characteristics of Patients During the Summer of 2012 in the Republic of Korea / 예방의학회지

OBJECTIVES: This study was conducted to investigate the relationship between heat-related illnesses developed in the summer of 2012 and temperature. METHODS: The study analyzed data generated by a heat wave surveillance system operated by the Korea Centers for Disease Control and Prevention during the summer of 2012. The daily maximum temperature, average temperature, and maximum heat index were compared to identify the most suitable index for this study. A piecewise linear model was used to identify the threshold temperature and the relative risk (RR) above the threshold temperature according to patient characteristics and region. RESULTS: The total number of patients during the 3 months was 975. Of the three temperature indicators, the daily maximum temperature showed the best goodness of fit with the model. The RR of the total patient incidence was 1.691 (1.641 to 1.743) per 1degrees C after 31.2degrees C. The RR above the threshold temperature of women (1.822, 1.716 to 1.934) was greater than that of men (1.643, 1.587 to 1.701). The threshold temperature was the lowest in the age group of 20 to 64 (30.4degrees C), and the RR was the highest in the > or =65 age group (1.863, 1.755 to 1.978). The threshold temperature of the provinces (30.5degrees C) was lower than that of the metropolitan cities (32.2degrees C). Metropolitan cities at higher latitudes had a greater RR than other cities at lower latitudes. CONCLUSIONS: The influences of temperature on heat-related illnesses vary according to gender, age, and region. A surveillance system and public health program should reflect these factors in their implementation.

Análise da contribuição das variáveis meteorológicas no estresse térmico associada à morte de cortadores de cana-de-açúcar / Analysis of the contribution of meteorological variables to thermal stress associated with death among sugarcane cutters

Os cortadores de cana-de-açúcar exercem atividade muito pesada e em condições precárias de trabalho. Além disso, fatores ambientais podem ser um importante agravante à sobrecarga térmica desses trabalhadores. Neste artigo, analisa-se a condição atmosférica no dia da morte de 14 trabalhadores do corte de cana-de-açúcar no Estado de São Paulo, Brasil. Compara-se valores estatísticos históricos da temperatura, umidade, vento e radiação com os valores destas variáveis meteorológicas observadas no dia de cada óbito. Os dados atmosféricos foram obtidos da reanálise do National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). Em 10 dos 14 casos analisados, as temperaturas observadas nos dias dos óbitos foram maiores ou iguais à média somada ao desvio-padrão. Em seis desses casos o valor da temperatura atingiu ou ficou muito próxima do recorde histórico. Constatou-se que a condição atmosférica pode ser um fator importante a ser considerado na análise das condições gerais de trabalho dos cortadores de cana-de-açúcar.

Sugarcane cutters perform heavy work under adverse conditions. Environmental factors can be an aggravating factor for thermal stress among these workers. This study analyzed the atmospheric conditions on the day of death of 14 sugarcane cutters in São Paulo State, Brazil. Historical data for temperature, humidity, wind, and sunlight were compared with the same meteorological variables on the days the deaths that occurred. The meteorological data were obtained from a reanalysis of the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). In 10 of the 14 cases, the temperature on the day of death was higher than or equal to the mean plus the standard deviation. In six of these cases, the temperature reached or came close to record levels. These findings suggest that atmospheric conditions can be an important factor in the analysis of overall work conditions for sugarcane cutters.

The effects of heat stress response on[Ca~(2+)] i of pulmonary arterial endothelium cells incubated with TNF-? / 中华麻醉学杂志

Objective The purpose of this study was to assess the effects of heat stress response (HSR) on i of pulmonary arterial endothelium cells (PAEC)incubated with TNF-?. We tried to illustrate the mechanism of injury to PAEC caused by TNF-? and the effects of HSR.Methods The study consisted of four groups.In group Ⅰ confluent monolayer of calf PAEC were directly incubated with TNF-? at final concentrations of 500, 1 000 and 2 000 u/ml for 24 h.In group Ⅱ PAEC were first bathed in 42℃ water for 20 min and then allowed to recover for 24 h.In turn they were incubated with TNF-? at the same concentrations.In group Ⅲ PAEC were not heated and incubated with TNF-?.In group Ⅳ PAEC were heated but not incubated with TNF-?.i of PAEC was assayed by fluorospectrophotometry and i of four groups were compared.The change in i before and after incubation of PAEC with TNF-?(?i) was calculated.Results (1) i was considerably higher in group Ⅰ than that in group Ⅲ at different concentrations in dose-dependent way.(2) Although i was higher in group Ⅳ than that in group Ⅲ, HSR could inhibit the further increase in i of PAEC incubated with TNF-?.Conclusions HSR may decrease the i in PAEC incubated with TNF-?.It indicates that HSR can prevent PAEC from calcium overload and provide protection on PAEC against injuries.