© Ahmedabad Municipal Corporation
Researchers are studying interventions, such
as drinking water stations, to see if they help
reduce deaths during heat waves in India.
By Shana Potash
An unprecedented and deadly heat wave struck the Indian city of Ahmedabad in 2010, killing hundreds of its most vulnerable citizens. Scorching temperatures reached a record 116 degrees Fahrenheit. The local government saw it as a wakeup call.
With global climate change predicted to fuel more frequent and intense heat waves, Ahmedabad's leaders made it a priority to develop South Asia's first action plan to protect people from extreme heat. The science-based approach aims to raise public awareness; build capacity of health professionals; provide early warning for dangerous heat; initiate measures to reduce exposure; and collect data to show the impact of heat on health and mortality. Since the plan was enacted in 2013, fewer deaths have been reported during Ahmedabad's hottest days, according to a preliminary analysis. Now, other cities are following Ahmedabad's lead.
The research guiding the adaptation effort was partially funded by the National Institute of Environmental Health Sciences (NIEHS), with additional support from Fogarty. An international team of investigators and local officials examined the burden of heat-related illnesses and considered how to better manage future heat waves. "We need to prepare now," says Dr. Dileep Mavalankar, a co-investigator and director of the Indian Institute of Public Health in nearby Gandhinagar. "You cannot build the well once the fire starts." Dr. Mavalankar, who earned a doctorate of public health from Johns Hopkins University, also worked as a visiting fellow at NIH in 1990-91.
Ahmedabad - located in the hot, dry northwest region of India - has a population of 7 million, many of whom live in slums. Extreme heat wasn't seen as a major health hazard and long-range forecasts for it didn't exist. That's changed. "One really important shift by virtue of this project was from 'it's always been hot here in India,' to 'we can do something about this,'" says Dr. Kim Knowlton, a co-investigator and senior scientist at the Natural Resources Defense Council.
During the lethal 2010 heat wave, there were 43 percent more deaths compared to the same time frame in other years, the researchers discovered. That amounts to an excess of 1,344 deaths from all causes. Scientists analyzed mortality and weather data to characterize the impact of the heat spike and identify temperatures at which mortality rises. The findings were used to set the temperature thresholds for the warning system that triggers alerts. The seven-day forecasts that initially gave the city time to prepare were from a partnering institution, Georgia Tech. The team now consults with India's national weather service, which has expanded its forecasts to help Ahmedabad and other jurisdictions plan for extreme heat.
Through a combination of surveys, focus groups, site visits and data analyses, investigators identified factors affecting vulnerability to heat and studied the health system's ability to handle heat emergencies. Special attention was given to patients of emergency medical services and to people highly exposed to the elements - slum dwellers with limited access to electricity and water, and construction workers and traffic police who work outside. Assessments led to interventions such as health care provider training, the establishment of drinking water stations, billboard postings of heat stress prevention tips, educational pamphlets, media alerts and text messages.
Public health messages on extreme heat, written in Gujarati and
placed on auto rickshaws, are part of Ahmedabad's heat action
Health effects of heat exposure range from rash, dizziness and fatigue to life-threatening heat stroke, which may cause delirium, seizures and even death. Extreme heat can contribute to heart attacks or kidney failure and leave survivors with an increased risk of mortality for years to come. Investigators learned that heat-related illnesses didn't necessarily occur to health workers making diagnoses, prior to receiving training on heat illness. High fever and altered mental state, for example, are signs not only of heat stroke but also malaria, which is common in the area. Training sessions were held to sensitize health professionals to the signs of heat-related illnesses and best practices for treatment.
Many of the interventions are low-tech, cost-effective and well suited for developing countries, investigators say. Emergency rooms and ambulances are now stocked with reusable ice packs. Sensitized by the campaign, a hospital administrator replaced the facility's black tar roof with heat-deflecting white tiles and moved the neonatal ward from the top floor to a cooler, lower floor.
Ahmedabad is serving as a model for other Indian cities that are developing their own heat response plans. "Increasingly, people are looking to the work we've done as an example of how to build resilience for climate variability and change," says principal investigator Dr. Jeremy Hess of the University of Washington. He emphasizes the importance of evaluation "to make sure the investments you're making are the right ones and that you're actually getting a more resilient population as a result."