Health

22 April 2010

Health defined as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity, is affected by climate change both directly and indirectly. People are exposed directly to changing weather patterns and indirectly through changes in the quality of water, air and food, and changes in ecosystems, agriculture, industry, human settlements and the economy. These direct and indirect exposures can cause death, disability and suffering.

WHO has identified five major health consequences of climate change. First, the agricultural sector is extremely sensitive to climate variability. Rising temperatures and more frequent droughts and floods can compromise food security. Increases in malnutrition are expected to be especially severe in countries where large populations depend on rain-fed subsistence farming. Malnutrition, much of it caused by periodic droughts, is already responsible for an estimated 3.5 million deaths each year.

Second, more frequent extreme weather events mean more potential deaths and injuries caused by storms and floods. In addition, flooding can be followed by outbreaks of diseases, such as cholera, especially when water and sanitation services are damaged or destroyed.

Storms and floods are already among the most frequent and deadly forms of natural disasters. The burden of climate sensitive diseases would be greatest for the poorest populations. Women and children in developing countries are particularly vulnerable to death and illness following natural disasters.

Third, both scarcities of water, which is essential for hygiene, and excess water due to more frequent and torrential rainfall will increase the burden of diarrhoeal disease, which is spread through contaminated food and water. Diarrhoeal disease is already the second leading infectious cause of childhood mortality and accounts for a total of approximately 1.8 million deaths each year.

Fourth, heatwaves, especially in urban “heat islands”, can directly increase morbidity and mortality, mainly in elderly people with cardiovascular or respiratory disease. Apart from heatwaves, higher temperatures can increase ground-level ozone and hasten the onset of the pollen season, contributing to asthma attacks. Stratospheric ozone depletion and the resulting higher concentration of UV rays in the lower layers of the atmosphere also results in cataracts and cancers in humans.

Changing temperatures and patterns of rainfall are expected to alter the geographical distribution of insect vectors that spread infectious diseases. Of these diseases, malaria and dengue are of greatest public health concern.

Increased Incidence and frequency of malarial outbreak will lead to higher percentage of women being affected with anaemia and an increased maternal mortality.

Global warming poses serious challenge to the health sector and hence warrants emergency health preparedness and response. This entails the proper and timely use of early warning systems, heat wave alerts, boil water alerts etc from the local governments. Also the primary healthcare centres should always be prepared and ready to deal with outbreaks of diseases.

An important aspect of health education is communicating best practices to the communities through various media. This includes training people to deal with emergencies and disasters and promoting behavioural change communication - use of pit latrines, hygienic water storage, washing hands and other hygiene practices.

Protection of health from climate change has to be a part of a basic, preventive approach to public health. There should be strict laws for water quality regulation. A Health Management Information System (HMIS) which monitors the outbreak of diseases should be put in place. Various vector control programmes should be undertaken to control the outbreak of diseases.