Global warming and kidney diseases
A mystery kidney that disease killed more than 20,000 people in Central America over the course of a decade had set alarm bells ringing in several tropical countries, including India. Those killed had similar profiles: they were young, their work involved hard labour and they worked long hours in the sun.
Now, a group of doctors in India have come together to re-establish the fact that the world could be witnessing its first human epidemic which is directly linked to global warming. The researchers have identified parts of the country (Andhra Pradesh, Tamil Nadu, Odisha, Goa and Maharashtra) with suspected sites of heat stress-associated nephropathy – caused by dehydration and heat.
Dr Georgi Abraham, a Chennai-based nephrologist, who was part of the research team, said global warming was not even in their mind when they started the study. ‘We just wanted to investigate why certain pockets had such high kidney ailments despite people not having diabetes, high blood pressure or obesity -the usual risk factors for kidney diseases.’
After they ruled out metabolic factors and possible presence of toxins, a study in Latin America gave the team its break – many sugarcane farmers in Nicaragua were hospitalised with chronic kidney diseases, which after probing was found to be linked to the practice of burning sugarcane during harvest.
‘The high temperature caused the workers to sweat and they weren’t drinking enough water,’ Abraham said. ‘The heat and dehydration took a toll on the kidney.’
In India, a team from JIPMER, undertook a similar study on salt pan workers in Puducherry and found the same result – increased creatinine levels, signifying impaired kidney functioning or renal disease. (Creatinine is a chemical waste product in the blood that passes through kidneys, which filter it before the body eliminates it in urine).
‘The impact isn’t immediate. Every day we noticed some degree of kidney damage and muscle breakdown because of the heat,’ said Dr Vivekanand Jha, professor of Nephrology at the George Institute for Global Health in New Delhi, who was part of the team. ‘That’s when we decided to look at global warming as a possible cause of this mysterious ailment.’
The study reiterates the significance of water intake especially during strenuous activities undertaken outdoors for long hours in the sun. Employers should provide water, shades to rest and frequent breaks to mitigate this risk. Occupational Health Physicians employed in the organized construction industry should take the first major step.
