Rising heat stress poses grave occupational health risk for workers in Tamil Nadu: Study

As global temperatures continue to soar due to climate change, the consequences of heat stress on outdoor workers like those who slog in salt pans are immense, a new study has said, emphasising the need for adaptation strategies and improved healthcare access to protect vulnerable individuals.

Between 2017 and 2020, 352 workers were studied in seven salt pans in Tamil Nadu and workload for different job roles and classified heat stress levels were evaluated. Key indicators such as pre-and post-shift heart rates, core body temperatures, urine characteristics, sweat rates, and kidney function parameters were measured.

The Study was conducted by a team led by Dr Vidhya Venugopal of Sri Ramchandra Institute of Higher Education and Research, who is also a co-Investigator of the UK NIHR Funded Global Health Research Centre that is focussing on the intersection of non-communicable diseases and environmental change.

The study found that every participant had either a heavy or moderate workload, and an alarmingly close to 90 per cent of workers were found to be working above the recommended limits of heat exposure.

The wet-bulb globe temperature (WBGT), a composite measure of environmental factors affecting human thermal comfort, consistently surpassed safe levels in the saltpans, particularly during summer months.

“The workers reported symptoms of heat strain, dehydration, and urinary tract infection symptoms, likely due to excessive sweating, lack of toilet access and limited water consumption during their shifts,” the study said.

Of particular concern is the impact of heat stress on kidney health, the study said, adding heat stress has been linked to various kidney-related issues, including acute kidney injury, kidney stones, chronic kidney disease, and urinary tract infections.

"We have compelling evidence that heat stress poses significant health risks for these workers. Urgent action is needed to implement adaptation strategies and improve healthcare, sanitation access and welfare facilities to protect the vulnerable individuals,” Dr Vidhya said.

The study underscores the fact that these workers experience prolonged exposure to high temperatures without sufficient access to adaptation strategies such as shade, rehydration, and rest breaks. Furthermore, many are hesitant to report symptoms of heat stress due to fear of job loss or retaliation. The risk is further magnified for undocumented workers who lack access to healthcare.

The study also highlights the urgent need for comprehensive measures to address heat-related risks for vulnerable workers.