Manikandan Krishnamoorthy, Vidhya Venugopal, Vettriselvi Venkatesan, Vijayalakshmi Jagannathan and Paul S.F.D.
Department of Environmental Health Engineering, Department of Human Genetics Sri Ramachandra University, Ramachandra Nagar Porur, Chennai, India.
Changing climatic scenario and raising temperature is likely to subject millions of working population across the globe to heat stress at their workplaces. Several epidemiological studies, including our own other studies, stand proof of the adverse effects of heat stress on the health of the workers. Heat stress imposes a strain on the physiology of workers exposed to heat stress that invokes physiological responses that includes induction of DNA damage and changes in the Heat Shock Protein (HSP) levels in blood. We conducted an extensive review and examined published data linking the relationship between occupational heat stress, changes in gene expression and HSPs induced by the DNA damage. Though the evidence for the mechanistic pathway is limited, reviewed literature shows strong evidence for the association between occupational heat stress, DNA damage and HSPs. We conclude that occupational heat stress is a significant risk factor and understanding its association with DNA damage will give key insights in how preventive interventions can be adopted to protect the working population from further adverse effects of occupational heat exposures.
Globally, rise in temperature had paved the way for health threats for millions of people. Excess heat exposures are not only an environmental threat but also an occupational hazard for millions of workers exposed to high heat conditions, especially in tropical settings. The workers with prolonged heat exposures in many jobs, both outdoors or in hot indoor environments, are subjected to heat stress with consequent heat strain symptoms. Heat stress, a proven environmental and occupational hazard is exposure to high heat environments and physical exertion, while “heat strain” is the physiological responses of the body to exposures to heat stress and “heat stroke” is a condition caused by your body overheating which may lead to unconsciousness and death. Workers are subjected to high air temperatures & humidity, radiant heat sources, direct physical contact with hot objects, and/or strenuous physical activities in many jobs. Workers in iron and steel industries, foundries, smelters, brick and ceramic industries, glass and rubber producing industries, boiler rooms of electrical utilities, bakeries, food canneries, commercial kitchens, laundries, chemical plants, outdoor and underground mines, and outdoor workers exposed to direct sunlight are subjected to high heat exposures on a day-to-day basis and have high potential for heat- related illness (HRIs). The heat exposures will also exacerbate preexisting chronic health conditions, such as respiratory, cardiovascular diseases and kidney diseases. Workers in mines, especially those who work in deep mines – geothermal gradients and equipment contribute to high heat and humidity exposures that can adverse health effects. Humidity in workplaces also contributes to heat stress and workers whose work entails wearing insulated clothing can encounter higher heat stress due to additional insulation for evaporative cooling; these include firemen, soldiers, asbestos workers, sandblasters, tank cleaners.