Electrolytes important in hot weather
US researchers have found that providing electrolyte drinks those working in hot and humid conditions can prevent muscle damage and associated complications. They noted that with rising global temperatures, outdoor agricultural laborers are increasingly exposed to heat and high humidity for extended periods. Plus their work can be extremely physically demanding, such as in manual sugarcane cutting, and is often performed in very hot, humid weather, especially in Latin America. The high intensity of the work coupled with extreme climate put agricultural workers at increased risk of dehydration and hypohydration (a state of decreased body water of two percent of body mass change due to sweat loss). Performing physical activity while losing body water impairs the body’s ability to dissipate heat, increasing the risk for heat-related illness and injury, such as acute kidney injury.
Agricultural workers in some parts of Australia would find themselves at similar risks. With summer approaching, the researchers' conclusions should be considered by employers here.
The researchers, from the Colorado School of Public Health at the Colorado University, provided 50 sugarcane workers in Guatemala with increasing amounts of electrolyte solution, from 2.5 litres per day to 10 litres per day, for two weeks over a three-week period where the average temperature ranged from 31.2 and 34 degrees Celsius. Workers were also allowed to freely drink plain water.
They found that increased electrolyte intake led to less muscle breakdown from physical exertion in hot conditions, and added that maintaining hydration is important for physical performance in the heat, because dehydration is associated with increased cardiovascular strain and reduced productivity and endurance. However, they also found mild hyponatremia – excessively low levels of sodium in the blood – in workers with higher levels of fluid intake, indicating overhydration.
Their trial demonstrated the feasibility of maintaining workers’ electrolyte levels under extremely hot and humid conditions while mitigating muscle injury. Electrolyte supplementation should be added to standard workplace water, rest and shade interventions to protect workers. They also recommended that workers be provided with training and information to reduce intake of plain water and replace it with an electrolyte solution.
The researchers concluded: “It is critical to understand the role that volume and electrolyte losses during the workday contribute to the onset of heat-related illness in order to improve upon existing acclimatization and occupational hydration/rest/shade programs and policies designed to prevent injury.”
Read more: Krisher, Lyndsay, et al, Electrolyte Beverage Intake to Promote Hydration and Maintain Kidney Function in Guatemalan Sugarcane Workers Laboring in Hot Conditions, and full article [pdf]. Journal of Occupational and Environmental Medicine, online first September 2020, doi: 10.1097/JOM.0000000000002033. Source: OHS Alert
