RESUMO
Workers may be exposed to conditions that put their physical and mental integrity at risk, from workplace settings to climate characteristics. Heat stress is a harmful health condition caused by exceeding the human body's tolerance limits, leading to illness and increasing the chance of work accidents. Heat stress indexes, such as the Humidex and the Heat Index (HI), are used to measure these impacts. These indexes are significant as they provide a quantitative measure of the heat stress experienced by workers, taking into account both environmental and individual factors. OBJECTIVE: This study aims to compare multiple heat stress indexes, relating them to historical Brazilian occupational accident data. METHODS: We selected eight indexes and applied multiple correspondence analysis to each one, a statistical method that generates graphs to visualize the association between variables in a database. RESULTS: The analysis and comparison of the graphs indicated that seven of the eight indexes presented similar behavior. It was also possible to relate ranges of index values with specific characteristics of the accidents. CONCLUSIONS: The technique allowed us to analyze the relationship between climate and work accidents and showed that the choice of the heat stress index does not significantly alter the results for most indexes studied.
Assuntos
Transtornos de Estresse por Calor , Saúde Ocupacional , Humanos , Transtornos de Estresse por Calor/epidemiologia , Brasil , Acidentes de Trabalho/estatística & dados numéricos , Clima , Temperatura Alta/efeitos adversos , Exposição OcupacionalRESUMO
The environment in which an animal is situated can have a profound impact on its health, welfare, and productivity. This phenomenon is particularly evident in the case of dairy cattle, then, in order to quantify the impact of ambient temperature (°C) and the relative humidity (%) on dairy cattle, the temperature-humidity index (THI) is employed as a metric. This indicator enables the practical estimation of the stress imposed on cattle by ambient temperature and humidity. A seasonal autoregressive integrated moving average (SARIMA) (4,1,0)(0,1,0)365 model was estimated using daily data from the maximum daily THI of 4 years (2016-2019) of the Comarca Lagunera, an arid region of central-northern Mexico. The resulting model indicated that the THI of any given day in the area can be estimated based on the THI values of the previous four days. Furthermore, the data demonstrate an annual increase in the number of days the THI indicates a risk of heat stress. It is essential to continue building predictive models to develop effective strategies to mitigate the adverse effects of heat stress in dairy cattle (and other species) in the region.
Assuntos
Indústria de Laticínios , Umidade , Temperatura , México , Bovinos , Animais , Indústria de Laticínios/métodos , Indústria de Laticínios/estatística & dados numéricos , Clima Desértico , Estações do Ano , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/epidemiologia , Modelos EstatísticosRESUMO
Heat stress can disrupt the balance between the heat poultry release into the environment and the heat they generate. Pequi oil has antioxidant properties, which may mitigate the heat stress effects. This study aimed to investigate the response of laying hens to pequi oil supplementation under heat stress using a proteomic approach. A total of 96 Lohmann White laying hens with 26 weeks old were housed in a completely randomized design with a 2 × 2 factorial arrangement. They were housed in two climate chambers, thermal comfort temperature ± 24.04 °C with the relative humidity ± 66.35 and heat stress (HS) ± 31.26 °C with the relative humidity ± 60.62. They were fed two diets: a control diet (CON), basal diet (BD) without additives, and with Pequi oil (PO), BD + 0.6% PO. After 84 days, plasma samples were analyzed using Shotgun and LC-MS/MS. Proteins related to anti-inflammation, transport, and the immune system were differentially expressed in hens fed PO and CON under heat stress compared to those in thermoneutral environments. This helps protect against oxidative stress and may support the body's ability to manage heat-induced damage, stabilizing protein expression under stress conditions. The ovotransferrin proteins, fibrinogen isoforms, apolipoprotein A-I, Proteasome activator subunit 4, Transthyretin, and the enzyme serine Peptidase Inhibitor_Kazal Type 5, which presented Upregulated (Up) equal to 1, present characteristics that may be crucial for enhancing the adaptive responses of hens to thermal stress, thereby increasing their tolerance and minimizing the negative effects of heat on egg production. The data presented in this manuscript provides new insights into the plasma proteome alterations of laying hens fed a diet supplemented with pequi oil during heat stress challenges.
Assuntos
Biomarcadores , Galinhas , Suplementos Nutricionais , Resposta ao Choque Térmico , Óleos de Plantas , Proteoma , Animais , Proteoma/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Feminino , Óleos de Plantas/farmacologia , Óleos de Plantas/administração & dosagem , Biomarcadores/sangue , Ração Animal/análise , Proteômica/métodos , Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/dietoterapia , Proteínas Sanguíneas/metabolismo , Proteínas Sanguíneas/análiseRESUMO
This study aimed to determine the global levels of DNA methylation and alterations in hematological and electrolytic parameters of two strains of laying hens subjected to heat stress and thermal comfort in climatic chambers. The experiment was conducted in two climate chambers with 192 laying hens of two strains: Dekalb White and Dekalb Brown. After the seven-day adaptation period, each climate chamber was programmed to a thermal condition for 28 consecutive days: Comfort (THI = 73.8) and Heat Stress (THI = 85.9). Blood samples were collected weekly. At each collection, a total of three milliliters of venous blood was collected from the ulnar wing or jugular vein. The experimental design was a randomized complete block design, with a 2 × 2 factorial scheme with split plots. Blood glucose, complete blood count, pH, ionized calcium, sodium, potassium, chloride, and global DNA methylation were evaluated. Stress increased chloride levels but did not affect the other evaluated blood parameters. At 28 days of the experiment, the Dekalb Brown strain showed higher levels of leukocytes and hematocrit and lower concentrations of chloride and sodium compared to the Dekalb White strain. Leukocyte levels, plasma protein, sodium, and ionized calcium remained above reference values for both strains. There were no methylation differences between temperature treatments, but a significant difference was observed between strains at 28 days of the experiment. Methylation patterns were independent of the evaluated blood parameters in this study but dependent on the bird strain, suggesting that strains respond with different biological mechanisms to heat adaptation. The absence of correlation does not completely exclude a causal relationship, and further studies are needed to investigate possible physiological and biological associations of blood and how strains respond to different heat adaptive mechanisms.
Assuntos
Galinhas , Metilação de DNA , Resposta ao Choque Térmico , Animais , Galinhas/sangue , Galinhas/fisiologia , Galinhas/genética , Feminino , Resposta ao Choque Térmico/fisiologia , Temperatura Alta , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/sangueRESUMO
Heat stress is a condition that impairs the animal's productive and reproductive performance, and can be monitored by physiological and environmental variables, including body surface temperature, through infrared thermography. The objective of this work is to develop computational models for classification of heat stress from respiratory rate variable in dairy cattle using infrared thermography. The database used for the construction of the models was obtained from 10 weaned heifers, housed in a climate chamber with temperature control, and submitted to thermal comfort and heat wave treatments. Physiological and environmental data were collected, as well as thermographic images. The machine learning modeling environment used was IBM Watson, IBM's cognitive computing services platform, which has several data processing and mining tools. Classifier models for heat stress were evaluated using the confusion matrix metrics and compared to the traditional method based on Temperature and Humidity Index. The best accuracy obtained for classification of the heat stress level was 86.8%, which is comparable to previous works. The authors conclude that it was possible to develop accurate and practical models for real-time monitoring of dairy cattle heat stress.
Assuntos
Doenças dos Bovinos , Transtornos de Estresse por Calor , Aprendizado de Máquina , Termografia , Animais , Bovinos/fisiologia , Termografia/veterinária , Termografia/métodos , Feminino , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/diagnóstico , Doenças dos Bovinos/diagnóstico , Indústria de Laticínios/métodos , Taxa Respiratória , Raios Infravermelhos , Temperatura Alta/efeitos adversosRESUMO
This study explores thermal stress conditions (i.e. heat, humidity, sunlight exposure) sports tourists can expect when attending the 2026 FIFA World Cup. Sports tourism's growth is driven by international mega-events like FIFA World Cups and Olympic Games. With planning ongoing for the 2026 FIFA World Cup football (soccer) tournament, what remains unstudied are the heat conditions spectators can expect at the 16 host stadiums in the United States, Mexico, and Canada. The inquiry is important considering (1) the tournament is taking place in warm-weather months of June and July, (2) thermal stress contributes to heat-related illnesses like heat stroke, and (3) many destination-bound tourists will be at elevated risk to heat. Accordingly, we report historical and forecasted thermal stress levels documenting expected conditions at each host stadium. Notably, forecasts indicate worsening thermal stress compared to long-term means, providing support for the study's methodology. Practical implications and limitations are provided.
Assuntos
Previsões , Temperatura Alta , Futebol , Humanos , Turismo , Transtornos de Estresse por Calor , Umidade , México , Luz Solar , Estados UnidosRESUMO
This study aimed to examine whether dietary supplementation of broiler chickens with turmeric essential could mitigate the effects of cyclic heat stress conditions. Intestinal and immunological parameters and gene expression were evaluated during the grower phase. A total of 320 21-day-old male Cobb 500 broilers were distributed according to a completely randomized design with a 4 (diet) × 2 (environment) factorial arrangement and eight replications of five birds each. Dietary treatments consisted of a basal diet without essential oil (EO, negative control) and three diets containing low (100 mg kg-1), intermediate (200 mg kg-1), or high (300 mg kg-1) levels of turmeric EO. In the heat stress group, dietary supplementation with turmeric EO at 100 and 200 mg kg-1 improved body weight, feed conversion, breast yield, and relative liver weight. These supplementation levels reduced villus width, increased villus/crypt ratio, reduced the H/L ratio, and improved hepatic (HSP70 and SREBP1) and intestinal (OCLN) gene expression in birds under heat stress. These findings support the hypothesis that turmeric EO can be used to improve or restore intestinal integrity, modulate inflammation parameters, and, consequently, enhance the performance of broilers challenged by cyclic heat stress.
Assuntos
Galinhas , Curcuma , Dieta , Suplementos Nutricionais , Expressão Gênica , Resposta ao Choque Térmico , Intestinos , Óleos Voláteis , Animais , Galinhas/imunologia , Galinhas/crescimento & desenvolvimento , Óleos Voláteis/farmacologia , Óleos Voláteis/administração & dosagem , Masculino , Intestinos/efeitos dos fármacos , Resposta ao Choque Térmico/efeitos dos fármacos , Dieta/veterinária , Expressão Gênica/efeitos dos fármacos , Ração Animal , Temperatura Alta , Fígado/metabolismo , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/prevenção & controle , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP70/genéticaRESUMO
BACKGROUND: Exposure to extreme heat impacts millions of people worldwide and outdoor workers are among the populations most affected by hot temperatures. Heat stress induces several biological responses in humans, including the production of heat shock proteins (HSP) and antibodies against HSP (anti-HSP) which may play a central role in the body's cellular response to a hot environment. OBJECTIVE: This longitudinal study investigated the impact of elevated temperatures and humidity on the presence of HSP70 and anti-HSP70 and examined relationships with markers of kidney function in an at-risk workforce under conditions of extreme heat and exertion in Guatemala. METHODS: We collected ambient temperature and relative humidity data as well as biomarkers and clinical data from 40 sugarcane workers at the start and the end of a 6-month harvest. We used generalized mixed-effects models to estimate temperature effects on HSP70 and anti-HSP70 levels. In addition, we examined trends between HSP70 and anti-HSP70 levels and markers of kidney function across the harvest. RESULTS: At the end of the harvest, temperatures were higher, and workers had, on average, higher levels of HSP70 and anti-HSP70 compared to the beginning of the season. We observed significant increasing trends with temperature indices, heat index, and HSP70 levels. Maximum temperature was associated with HSP70 increments after controlling for age, systolic and diastolic blood pressure (ß: 0.21, 95% Confidence Interval: 0.09, 0.33). Kidney function decline across the harvest was associated with both higher levels of anti-HSP70 levels at the end of the harvest as well as greater increases in anti-HSP70 levels across the harvest. CONCLUSIONS: These results suggest that workplace heat exposure may increase the production of HSP70 and anti-HSP70 levels and that there may be a relationship between increasing anti-HSP70 antibodies and the development of renal injury. HSP70 holds promise as a biomarker of heat stress in exposed populations.
Assuntos
Biomarcadores , Fazendeiros , Proteínas de Choque Térmico HSP70 , Temperatura Alta , Exposição Ocupacional , Humanos , Proteínas de Choque Térmico HSP70/imunologia , Proteínas de Choque Térmico HSP70/sangue , Estudos Longitudinais , Masculino , Biomarcadores/sangue , Adulto , Feminino , Exposição Ocupacional/efeitos adversos , Temperatura Alta/efeitos adversos , Pessoa de Meia-Idade , Guatemala , Rim , Agricultura , Anticorpos/sangue , Transtornos de Estresse por Calor , UmidadeRESUMO
Heat stress has been recognized as a serious problem in dairy farms around the world due to the increasing heat waves and higher genetic potential of dairy cows. In Chile, milk production is concentrated in the southern regions of the country, where animals graze all year around, consequently being exposed directly to environmental conditions. Nevertheless, there are few studies conducted in Chile that have evaluated at the commercial level the impact of heat stress on milk production. The aim of this study was to assess the effects of summer conditions, across periods, on the milk production of cows at different stages of lactation in a dairy farm located in Southern Chile. Daily meteorological and milk yield records of three summers from a dairy farm were collected to characterize the relationship between two thermal stress indices and milk yield. The thermal comfort indices used were the comprehensive climate index (CCI), and the adjusted temperature humidity index (THIadj). The average values of CCI and THIadj were dependent on the period (P < 0.0001) with maximum CCI of 40.2 °C, 31.7 °C, and 27.5 °C for the 2012-2013, 2015-2016, and 2016-2017 periods, respectively. A similar response was recorded when THIadj was used (85.5, 78.0, and 73.9, respectively). In the 2012-2013 summer, 44.4% of the days presented conditions of heat stress (CCI ≥23), a value that fell to 26.7% in the summer of 2015-2016 and only 5.6% in the 2016-2017. On the opposite, when the THIadj was used, these values were 50%, 48.9%, and 5.6%, respectively. In conclusion, both comfort thermal indices are good tools to determine the risk of thermal stress in dairy cows, with a large variation between the three summer periods but also between indices. Likewise, cows in the early and mid-lactation periods are more affected in terms of milk yield.
Assuntos
Resposta ao Choque Térmico , Lactação , Animais , Bovinos/fisiologia , Feminino , Chile , Indústria de Laticínios , Umidade , Leite/metabolismo , Estações do Ano , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/fisiopatologia , Temperatura Alta/efeitos adversosRESUMO
The objective of the present study was to evaluate a blend of functional oils (FO) composed of copaiba and garlic essential oils, pepper oleoresin and cashew nut liquid to mitigate the effects of heat stress on productivity, egg quality, organ morphology of the gastrointestinal tract, serum biochemical profile, nutrient metabolism and body temperature of Japanese quail. A completely randomized design was used in a 3 × 2 factorial scheme (without additive; 300 and 500 mg FO/kg of feed x birds raised in a thermal comfort (TC) and heat stress (HS) environment), with 6 replicates of 8 birds per plot. The birds under HS had lower feed intake (P = 0.0000), egg mass (P = 0.0000), laying rate (P = 0.0000) and higher percentage of infertile non-commercial eggs (P = 0.0004), lower head temperature amplitude (P = 0.0000) and higher average of body temperature (P = 0.0312). HS worsened the external and internal quality of the eggs. Birds kept in HS showed higher values of cholesterol (P = 0.0000) and glutamic-pyruvic transaminase (P = 0.0272). The use of 300 and 500 g FO/ton of feed improved the feed conversion (P = 0.0000) and egg mass (P = 0.0000) of the quail bred under HS, respectively, by 8.4 and 7.2% and increased the relative weight of liver (P = 0.0064) and pancreas (P = 0.0492). The use of such additives also provided a higher % of yolk (P = 0.0018) and reduced the percentage of albumen (P = 0.0029) of the eggs produced in TC, in addition to reducing the amplitude of head temperature (P = 0.0484) of birds bred under HS. The breeding of Japanese quail under HS results in negative impacts on the production, physiological and qualitative aspects of the eggs. The use of 300 g/ton of FO in the diet of Japanese quail leads to improvements in feed conversion, increased liver capacity in nutritional metabolism and results in eggs with a higher proportion of yolks, being, therefore, an alternative for feeding quail in a hot climate.
Assuntos
Ração Animal , Coturnix , Dieta , Óleos de Plantas , Animais , Coturnix/fisiologia , Ração Animal/análise , Dieta/veterinária , Óleos de Plantas/administração & dosagem , Óleos de Plantas/farmacologia , Feminino , Distribuição Aleatória , Suplementos Nutricionais/análise , Resposta ao Choque Térmico/efeitos dos fármacos , Óleos Voláteis/administração & dosagem , Óleos Voláteis/farmacologia , Anacardium/química , Temperatura Alta/efeitos adversos , Alho/química , Transtornos de Estresse por Calor/veterináriaRESUMO
The study aimed to estimate economic losses associated with heat stress in the eight dairy production regions (DPR), defined by the Dairy Chilean Consortium, using two comfort thermal indices, namely, the temperature-humidity index (THI) and the THI adjusted for solar radiation and wind speed (THIa). Hourly records from 19 weather stations (Nov - Mar 2017-2022) were collected to estimate the comfort thermal indices. The economic impact was estimated considering a critical threshold of 65 for both indices and the effect of higher values on loss in milk yield, days open, culling rate, and deaths. There were differences in the number of hours above the threshold among DPRs, independent of the thermal index used (P < 0.01). The greatest values were observed in DPRs I, II, and VIII, which concentrate most dairy cows. Average losses in milk yield were between 2.0 and 6.4 times higher when THIa was used instead of THI, which also depends on the DPR (P < 0.01). These estimations coincide with those observed empirically by producers. The lowest average economic losses per cow during the summer season (5 seasons average) occurred in DPR VI (US $ 91.5), and the highest losses were observed in DPR I (US $ 184.2) both using THIa. At the country level, economic losses fluctuate between US $ 29.0 and 108.4 million per summer season, depending on the comfort thermal index used. Finally, heat stress impacts negatively and significantly the Chilean dairy sector, which is highly dependent on the DPR.
Assuntos
Indústria de Laticínios , Transtornos de Estresse por Calor , Animais , Chile , Bovinos , Indústria de Laticínios/economia , Feminino , Transtornos de Estresse por Calor/economia , Transtornos de Estresse por Calor/veterinária , Umidade , Leite/economia , Temperatura Alta/efeitos adversos , Doenças dos Bovinos/economia , Doenças dos Bovinos/epidemiologia , Temperatura , Lactação , Estações do AnoRESUMO
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.
Assuntos
Injúria Renal Aguda , Transtornos de Estresse por Calor , Saccharum , Humanos , Nicarágua/epidemiologia , Injúria Renal Aguda/epidemiologia , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Transtornos de Estresse por Calor/epidemiologia , Temperatura Alta/efeitos adversos , Exposição Ocupacional/efeitos adversosRESUMO
Heat stress is a major factor that negatively affects animal welfare and production systems. Livestock should adapt to tropical and subtropical areas and to meet this, composite breeds have been developed. This work aimed to evaluate gene expression profiles in the skin of Brangus cattle under heat stress using a case-control design, and to correlate this with skin histological characteristics. Two groups of bulls were set using rectal temperature as a criterion to define stress conditions: stressed (N = 5) and non-stressed (N = 5) groups. Skin transcriptomics was performed and correlations between breed composition, phenotypic and skin histological traits were evaluated. Results showed 4309 differentially expressed genes (P < 0.01), 2113 downregulated and 2196 upregulated. Enrichment and ontology analyses revealed 132 GO terms and 67 pathways (P < 0.01), including thermogenesis, glycolysis, gluconeogenesis, mitochondrial activity, antioxidant and immune response, and apoptosis. The identity of the terms and pathways indicated the diversity of mechanisms directed to relieve the animals' suffering, acting from simple passive mechanisms (conduction, convection and radiation) to more complex active ones (behavioural changes, evaporation, vasodilation and wheezing). Furthermore, significant differences between phenotypic and skin histological traits and correlations between pairs of traits suggested a direction towards heat dissipation processes. In this sense, number of vessels was positively correlated with number of sweat glands (P < 0.001) and both were positively correlated with zebuine genetic content (P < 0.05 and P < 0.01, respectively), gland size was positively correlated with epidermal thickness and negatively with hair length (P < 0.05), and epidermal thickness was negatively correlated with gland-epidermis distance (P < 0.0005). These results support the notion that response to heat stress is physiologically complex, producing significant changes in the expression of genes involved in several biological pathways, while the animal's ability to face it depends greatly on their skin features.
Assuntos
Resposta ao Choque Térmico , Pele , Transcriptoma , Animais , Bovinos/genética , Bovinos/fisiologia , Resposta ao Choque Térmico/genética , Masculino , Pele/metabolismo , Perfilação da Expressão Gênica , Transtornos de Estresse por Calor/veterinária , Transtornos de Estresse por Calor/genética , Transtornos de Estresse por Calor/metabolismoRESUMO
The growing body of scientific literature underscores the intricate relationship between meteorological conditions and human health, particularly in the context of extreme temperatures. However, conventional temperature-centric approaches often fall short in capturing the complexity of thermal stress experienced by individuals. Temperature alone, as a metric, fails to encompass the entirety of the thermal stress individuals face, necessitating a more nuanced understanding. In response to this limitation, climatologists have devised thermal indices-composite measures meticulously crafted to reflect the intricate interplay of meteorological factors influencing human perception of temperature. Recognizing the inadequacy of simplistic temperature-focused methodologies, our study aims to address the multifaceted nature of thermal stress. In this study, we explored the association between thermal indices and hospital admissions for circulatory and respiratory diseases in Brazil. We used an extensive dataset spanning 11 years (2008-2018) from the Brazilian Ministry of Health, encompassing a total of 23,791,093 hospitalizations for circulatory and respiratory diseases. We considered four distinct thermal indices-Discomfort Index (DI), Net Effective Temperature (NET), Humidex (H), and Heat Index (HI). We used an extension of the two-stage design with a case time series to assess this relationship. In the first stage, we applied a distributed lag non-linear modeling framework to create a cross-basis function. We next applied quasi-Poisson regression models adjusted by time-varying confounders. In the second stage, we applied meta-analysis with random effects to estimate the national relative risk (RR). Our findings suggest robust variations among the thermal indices under examination. These variations underscore the intricate nature of associations between temperature and health, with each index capturing distinct aspects of thermal conditions. Our results indicate that extreme thermal conditions, both at the low and high ends, are associated with increased risks of hospital admissions. The diverse impact observed among different indices emphasizes the complex interplay between various meteorological factors and their specific physiological consequences. This underscores the necessity for a comprehensive comprehension of temperature metrics to guide precise public health interventions, recognizing the multifaceted nature of temperature-health relationships.
Assuntos
Doenças Cardiovasculares , Hospitalização , Brasil , Humanos , Hospitalização/estatística & dados numéricos , Doenças Cardiovasculares/epidemiologia , Doenças Respiratórias/epidemiologia , Transtornos de Estresse por Calor/epidemiologia , Temperatura AltaRESUMO
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.
Assuntos
Eficiência , Fazendeiros , Transtornos de Estresse por Calor , Temperatura Alta , Exposição Ocupacional , Insuficiência Renal Crônica , Humanos , Masculino , Fazendeiros/estatística & dados numéricos , Feminino , Adulto , Temperatura Alta/efeitos adversos , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/prevenção & controle , Exposição Ocupacional/estatística & dados numéricos , Nicarágua , Transtornos de Estresse por Calor/prevenção & controle , Saccharum , Adolescente , Descanso/fisiologia , Agricultura/métodos , Doenças dos Trabalhadores Agrícolas/prevenção & controle , Doenças dos Trabalhadores Agrícolas/etiologiaRESUMO
Strategies to alleviate heat stress on live performance - dry matter intake (DMI), average daily gain (ADG), and feed conversion efficiency (FCE) - and on physiological parameters - respiratory rate (RR) and panting score (PS) - of feedlot-finished cattle were evaluated by systematic review-meta-analysis. Using the PICO framework were identified 3813 records, with 31 publications and 6729 cattle being considered in the meta-analysis (MA). The comparison most reported was sun vs. shade (n = 24 publications), followed by shade vs. shade (area per animal and effectivity in reduce solar load) (n = 7 publications) and sun vs. sprinkling (n = 4 publications). Cattle with access to shade with total reduction in solar load improved ADG (p = 0.008) and FCE (p = 0.024), and reduced RR (p < 0.001) compared to unshaded animals. Cattle with access to shade with a height between 3 and 4 m increased ADG (p < 0.001), tended to improve FCE (p = 0.054), and reduced RR (p < 0.001) compared to unshaded animals. An area of shade from 2 to 4 m2/animal increased ADG (p = 0.002), and higher than 4 m2/animal reduced RR (p < 0.001) compared to unshaded animals. Animals that received sprinkling volume below 1 L/animal/min improved ADG (p = 0.008) compared to unshaded animals. Cattle with access to shade with a high area per animal improved DMI (p = 0.023) and ADG (p < 0.001) compared to animals with a low area. In univariate meta-regression, it was observed that the variables significantly (P < 0.05) influencing DMI were THI category; influencing ADG were cattle gender, THI category, and coat color; influencing FCE were cattle age and hemisphere; and influencing RR were country, THI category and climate. Performance and physiological parameters of feedlot-finished cattle under heat stress depend on animal and environmental characteristics.