New Delhi: Risk of an emergency visit to a hospital for a heart problem could be six times higher on hot and humid days, compared to hot days with low humidity, according to an analysis of over 3.4 lakh such visits during 2014-2019 in Dhaka, Bangladesh.
Researchers from Tulane University in the US and Bangladesh’s National Institute of Cardiovascular Diseases modelled the emergency visits made during summer months against historical data of temperature and humidity in Dhaka.
Findings published in the journal Science of The Total Environment reveal that while heat alone can heighten the risk of a heart-related emergency by 4.4 per cent, on most humid days — with relative humidity peaking at 82 per cent — the risk rose to 26.7 per cent.
“(The study’s) findings show we need to consider heat and humidity together when we discuss any kind of climate change policy,” said first author Mostafijur Rahman, an assistant professor of environmental health sciences at Tulane University’s School of Public Health and Tropical Medicine.
Under continued global warming, the number of hot and humid days in a year is projected to increase, with tropical countries said to be more vulnerable.
Humid conditions — high moisture in the air — hampers one’s ability to sweat and bring down the body’s temperature, forcing the heart to pump harder.
The findings could help develop solutions in Bangladesh and similar countries, where exposure to high heat and humidity can drive up the risk of heat-related illness, the authors said.
“There are billions around the world — from Southeast Asia to Africa — who are directly impacted by rising temperatures but have little access to air conditioning,” Rahman said.
The authors wrote, “The effect size of heat increased linearly with increasing (relative humidity) and culminated in a six-fold increase in excess risk on the most humid days (relative humidity ranges between 82 per cent and 97 per cent) as compared to days with normal humidity (between 34 per cent and 69 per cent) [excess risk 26.7 per cent vs 4.4 per cent].”
“Hopefully, governments will be spurred to develop systems to warn cities of dangerous heat and humidity. For average citizens, it’s important to develop habits to beat the heat: stay hydrated, stay indoors, wear breathable clothing, and consider visiting air-conditioned public places like malls or libraries,” Rahman said. PTI>
