Heatwave in India – implications for workers

It’s rare that the concerns of ordinary workers makes the news in Europe, but over the past few days there have been reports in the British press about fatalities being caused by a severe heatwave in India.

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(Picture Source; www.commondreams)

According to the Guardian over 2,200 people have died

Andhra Pradesh has been hit the hardest, with 1,636 people dying from the heat over the past month and a half, a government statement said. A further 561 people have died in neighbouring Telangana, said Sada Bhargavi, a state disaster management commissioner.

Environmental conditions have been severe. The Guardian reports

Daytime temperatures hovered between 45C and 47C (113-116 F) in parts of the two states over the weekend, 3-7C (5-12F) above normal, said YK Reddy, a director of the Meteorological Centre in the Telangana state capital of Hyderabad.

The risk from heat stress depends not only on the environmental conditions but also on other factors, particularly

  • workload
  • clothing
  • individual susceptibility

Workers carrying out heavy work for prolonged periods in hot conditions are particularly at risk as they generate significant “internal” heat as well as absorbing it from the environment. Susceptible individuals include the elderly and people who are malnourished. Not surprisingly, then, the majority of the people who have died during the heatwave have been the elderly and manual labourers working outdoors.

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Agricultural workers in India (source Wikipedia)

There are over 3 million construction workers employed in India (the figure is likely to be higher if “informal” workers are included) and many millions more working in agriculture (almost 50% of the workforce). Construction and agriculture are also major industries in other hot countries in the developing world, and there have been reports of numerous heat related illnesses and fatalities linked to manual work in hot conditions in countries such as Qatar, where there has been a boom in construction due to preparations for the 2022 World Cup.

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Construction workers in Qatar (toehk under a Creative Commons Licence via New Internationalist)

The most effective ways to minimise the risks are to prevent exposure or to introduce engineering controls supplemented with work organisation and protective clothing. However engineering controls are impractical in most cases for outdoor workers in the developing world and the so the main way to minimise the risk of workers being adversely affected is to restrict the working time through work:rest regimes or “self pacing” and other administrative /management measures such as providing plenty of cool drinking water. In practice, most employers are unlikely to look favourably on this due to the impact on productivity and profitability. Subsistence farmers are unable to afford the technology available in the developed world (such as air conditioned cabs and automation) that could be applied to reduce their heat exposure and workload and need to work hard for long hours to have a chance of growing enough to survive.

Extreme events like the current heatwave in India are likely to become more frequent in the future due to climate change and it’s not just the developing world that will be affected. The populations of Europe and the United States are also likely to face exposure to heat extremes.

These events present challenges to occupational hygienists. First of all we currently don’t have an adequate method of evaluating the risk in these situations, particularly in the developing countries. The widely used WBGT index has serious limitations and the more complex Predicted Heat Strain Index is far too complex to be used in most situations. So work needs to be done to develop a suitable approach to risk assessment for the developing world. Secondly, given the scale of the problem, there’s a need to find appropriate, effective strategies to reduce and control exposures. Neither are easy tasks. However, some good work has been done on this in countries including India and Abu Dhabi and so the third challenge is persuading employers to adopt the guidance.

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Feeling the Heat

My second presentation at the Health and Wellbeing at Work event last Tuesday focused on managing heat stress in the workplace.

The risks from working in hot environments is often neglected, but there have been a number of fatalities, and some serious, but non-fatal incidents, in the UK recent years due to workers experiencing heat stress and strain.

My presentation covered

  • how the body is affected by heat
  • the factors that need to be considered when assessing the risk (and it’s not just the air temperature)
  • a structured approach to assessing the risk
  • an introduction to how the risks can be controlled.

I’ve uploaded my presentation to Slideshare, and here’s an embedded copy.

TLVs for heat stress

This week we’re running the BOHS module M201 Thermal environment and non-ionising radiation (including lighting). This is one of the optional modules and most hygienists will only come across problems related to these topics on rare occasions. Consequently, after the course, it can be difficult to keep up to date with new research and developments.

One of the important aspects of heat stress covered on the course are the standards used when evaluating the risk. There are no legal limits in the UK relating to work in hot environments, so most hygienists will turn to the threshold limit values (TLVs) set by the American Conference of Governmental Industrial Hygienists (ACGIH) for guidance when faced with a potential heat stress problem. In the past the TLVS have often been used to establish work:rest regimes for work in hot conditions, as restricting working time is a practical measure that can allow work to take place while minimising the risk to the employees’ health. Unfortunately the emphasis placed on this organisational measure, meant that other, more effective, approaches such as looking for ways to avoid work in stressful conditions and engineering controls to reduce heat stress at source or along the transmission path, could be neglected

The TLVs were, however, updated a few years ago and now place less emphasis on work:rest regimes, adopting a more thorough, structured approach to reducing and managing the risks from work in hot environments. ACGIH have produced a flow chart that summarises the new procedure (a copy can be downloaded from Professor Thomas E. Bernard’s website  here or click on the diagram below), but it is fairly complex can be difficult to follow at first.

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I’ve produced a summary presentation on the TLV, which includes some worked examples for use on our course which I’ve uploaded to Slideshare . I’ve embedded it below, but you can view it on the Slideshare site here,  from where it can also be downloaded, if you prefer.