Jul 01, 2015
Heat waves are likely to rapidly increase as climate change progresses, says Dr Dileep Mavalankar.
New Delhi: India is reporting thousands deaths from various states due to heat wave in May 2015, the second highest reported in any heat wave in India. This number may go up still. But many people and agencies are not aware that heat-related deaths are many times more than commonly-identified heat-stroke deaths.
For example in 2003, Europe had a major heat wave which killed 70,000 people. Of those, direct heat stroke deaths were very few; most were deaths of older people with some chronic disease who died due to overheating of the body and failure of heart, circulation, lungs or kidneys.
India has weak registration of deaths, recording of cause of death and analysis of cause of deaths. This limits our ability to estimate the total number of deaths due to heat waves. What is widely reported are very obvious cases of “heat stroke,” which happen due to direct exposure to heat on roads or at work. In such cases people die within hours of heat stroke. These are called direct heat stroke or Exertional heat stroke. When body temperature goes above 104 °F it can lead to brain damage and the chance of death is very high – about 30-40 percent. Other more common and but more insidious is indirect heat stroke or non-exertional heat stroke.
This happens among elderly or people with chronic health conditions like heart, lung or kidney diseases, which worsen by very hot temperature. They may also have dehydration and electrolyte imbalance in blood. Such cases may happen at night or within one or two days of the heat wave. They may die if not treated properly. In India we do not keep track of such heat-related deaths as most of the times doctors do not correlate heart or kidney failure that killed the patient to a heat wave.
For example only 76 heat stroke deaths reported by 5 major city hospitals in Ahmedabad during 2010 heat wave. If you add other major hospitals the number may go up to 150 deaths due to heat stroke. Against this our analysis of the death registration data of the city showed 800 additional deaths from a all causes in the week of the health wave and overall about 1300 additional deaths in May 2010 as compared to baseline expected mortality for the city in May. Thus there is gross under reporting of heat related mortality even in cities. Under reporting of deaths in rural areas are even more.
The registrar of births and deaths (RBD), a statutory officer in each city and state, and Registrar General of India (RGI),an officer of the home ministry, should be publishing daily or weekly mortality numbers by cause in cities, states and country at least during heat waves and epidemics. This is not happening. Health departments and disaster management agencies could be keeping track of increases in mortality in the population, and correlate it to environmental factors on daily, weekly and monthly basis. They should also develop early warning systems to prevent such mortality.
Following major Plague epidemics, London developed a system called “Bills of Mortality” way back in 1660s to count and analyze all deaths happening in the city by cause and alerting the citizens of epidemics. In India today we do not have such system of daily reporting of death by cause to pick up epidemics or increase in mortality due to events like heat waves early. Cause of death and calculation of area-specific death rates is like compass to a ship’s captain. Without such compass, one cannot navigate our health system in as sea of disease and disasters.
Heat waves are likely to rapidly increase as climate change progresses. We need to assess on daily basis the total mortality associated with heat waves and not only report “heat stroke” deaths – which are a mere tip of the ice berg. Not reporting deaths does not make them go away.
Ahmedabad city municipal corporation has developed South Asia’s first Heat Action Plan in 2013,with a coalition of local and international scientists and policy experts from the Indian Institute of Public Health, Gandhinagar, Natural Resources Defense Council, Mount Sinai hospital, and Emory University USA – the Ahemdabad heat Action Group. Georgia Institute of Technology's CFAN group provides a pioneering daily 7-day forecast for Ahmedabad.This plan has helped it to reduce mortality and morbidity in heat waves. If Ahmedabad can do it, other cities and districts in India can do it too. It is a question of political will. It is much easier than sending rocket to Mars and will also cost much less, but will save thousands of lives in future heat waves.
Dr Dileep Mavalankar is Director at the Indian Institute of Public Health, Gandhinagar.