Climate change threatens health

Melanie Gosling: The Cape Times, 10 August 2012

South Africa already has a heavy burden of disease, and climate change is set to make it worse. While many may be aware that warmer temperatures may lead to the expansion of areas affected by diseases such as malaria, they may be less aware that climate change may exacerbate a range of other health problems, such as diarrhoea, or depression. UCT professor Jonny Myers, director of the university's Occupational and Environmental Health Unit, said climate change would affect the fundamental requirements for health: safe drinking water, clean air, sufficient food and secure shelter. These changes would have both direct and indirect health effects.

In a paper published by the SA Medical Journal, Myers presented a model which aims to help identify the most important health risks associated with climate change and show the causal links. Some of the climate change health impacts will be the direct result of "extreme weather events", such as heat waves, fires, hurricanes, droughts and floods, and others are indirect results from crop failure, from damaged infrastructure, for instance water pipes, and from displacement of communities and conflict. Myers said there was evidence that high temperatures caused excessive deaths among the elderly population with chronic lung and heart disease. Cardiovascular problems were more common in hot temperatures. Waterborne diseases are affected by changes in rainfall patterns which affect river flows. This can lead to a spread of diarrhoeal diseases, including cholera, as well as hepatitis A and E.

There is an increased risk of malnutrition from impaired agriculture or from the loss of rural livelihoods, and an increased risk of respiratory illnesses from air pollutants. Cardiovascular system diseases, such as heart attacks and strokes, worsen as a result of air pollution, and renal disease is associated with heat waves

In southern Africa, the vector-borne diseases dengue fever and tick-borne encephalitis and plague are predicted to increase with climate change. Worsening climate and environmental conditions will lead to an increase in migration and refugees, causing social tensions and violence. Indirect health consequences of climate change include anxiety, depression and post-traumatic stress disorder from displacement, loss of family, disabling injuries and loss of livelihoods. Drug and alcohol abuse are more prevalent among displaced people and those subjected to extreme environmental or climate stress.