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Dehydration at work - minimizationnd managing it.

Dehydration is a serious problem in workplaces - it can reduce employee productivity and morale, and increases the risk to everyone in the workplace.

To minimise the risk, it is essential for both employees and the employer to know the warning signs and symptoms of dehydration and the factors that increase the risk of dehydration. It is also necessary to develop preventive measures individually tailored to the environment and the needs of individual workers.

In this guide, we outline dehydration prevention, management and monitoring methods, as well as realistic and easy-to-implement advice on how to minimize dehydration. 

What is dehydration?

The body of the average adult male, depending on the state of health, consists of 50-70% water; on average, the body of a healthy 70 kg male contains 60% water (approximately 42 l). During sedentary work, approximately 2-4 litres of water (3-6% of body weight) is lost daily through urination, faeces, during breathing or through the skin.

Mild symptoms of dehydration:
Dehydration at a level of 15% is likely to cause death, but even mild dehydration - classified as a loss of 1-4% of body weight in fluids - can cause a serious safety risk in the workplace, as well as lowering productivity and employee morale.

  • Dehydration at 1%, or about 0.7 litres for a 70kg body, leads to impaired physical performance while impairing our cognitive abilities such as concentration, alertness and reaction times.
  • At 2% dehydration - that is, the moment we start to feel thirsty - our heart rate is already elevated by around 8 beats per minute and overall performance drops by up to 30%.
  • If we do not replenish fluids and the body continues to dehydrate to the point of losing 3% of its mass, cognitive abilities may be impaired and the effect will be similar to a blood alcohol content of 0.08. Such a condition has been found to slow down drivers' reaction times by 17% and increase the chances of causing a car accident by as much as 5 times.
  • Dehydration at 4% slows coordination and reaction times even further. It has been detected that miners in Australia often join shifts with mild dehydration. Research shows that recovery during a shift is unlikely, meaning that miners are working with reduced cognitive function, putting themselves and their colleagues at great risk.

Who is at risk of dehydration?

Production and lower-level administrative workers are most at risk of dehydration due to the fact that they regularly perform heavy physical work in hot and humid weather conditions, which significantly increases sweat output.

In addition, many workplaces require the wearing of personal protective equipment (PPE), which further reduces the body's ability to lower its temperature, which in turn speeds up the sweating process.

Those working in high temperatures and high humidity where there is also poor airflow - such as underground mine workers - are also at high risk. Workers in cold climates are also at risk of dehydration, as cold weather can reduce thirst by around 40%, even when the body needs fluids. In addition, cold conditions mean that when the body is dehydrated, the brain sends weaker signals to the kidneys about the body's need to retain fluids. 

This phenomenon is explained by the fact that peripheral blood vessels exposed to the cold begin to constrict, causing the blood to give off less heat to the environment, which in turn means that the brain is less likely to detect the onset of a dehydrated state and therefore less likely to release thirst-stimulating hormones and retain fluids in the body.

It appears that the body is likely to lose significant amounts of fluids in cold weather. This is because when we inhale cold air - which has less humidity than warm air - it is first heated up inside us and then, before being expelled outside, 'saturated' with moisture, and another portion of dry and cold air takes its place.

Stress simulation studies of construction workers have shown that 4.1 litres of sweat are secreted when working a 10-hour shift at 15-20°C. In comparison, this amount increases to 4.7 litres at 30-35°C. In addition, approximately 40% higher concentrations of sodium in sweat were found during exertion at lower temperatures due to the lack of heat acclimatisation in the subjects.