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Global Warming and Diseases
Our Earth is suffering from global warming. It is not only affecting the weather but also pattern of human diseases.
(Posted on 8 June 2006)
George was having a debate with his old rival in the medical school, Peter, at a reunion dinner over the issue of global warming.
"Scientists in the United Nations have agreed that the earth's temperature would rise by 2 to 2.5oC by the end of this century. The glaciers would melt. People would die like flies." George said, quoting studies on the 2003 heat waves in Europe and a recent review in The Lancet.
"Scaremongering!" Peter said. "A warmer climate would mean a shorter winter. Less people would die from extreme cold." Peter works in the casaulty. He knows that death rate is higher in winter.
George argued that insects are cold blooded animals. A hotter climate and a prolonged summer would increase their reproductive and biting rates. "A higher temperature would increase the risk of diseases transmitted by insects," he said.
Philip joined the discussion. He is a microbiologist. The malaria parasite, he said, requires an average temperature of above 16oC to develop inside a mosquitoes' body. Higher temperature means malaria and other diseases transmitted by mosquitoes such as dengue fever and encephalitis would be more common. A hotter and wetter weather would also favor disease-carrying pests such as ticks and rats, whose breeding-grounds are often in areas warm and damp.
"Food poisoning would also increase and even cholera may return. Blooms in marine phytoplankton may also result in red tides that cause diarrhea and paralytic diseases." Philip warned additionally. Increases in temperature of coastal waters can lead to more water-borne infections because the bacteria causing these diseases can survive freely in warm sea water.
"Wait a minute," Peter said. "The risk of these infectious diseases is more related to a society's hygienic standard and public health measures. It's the economy that's more important. Singapore is in the tropics but their people enjoy long life expectancy."
"No, see how Hurricane Katrina has devastated New Orleans in America." George retorted. "As the ocean is getting warmer, tropical storms can pick up more energy and become more powerful. Established health infrastructure can be damaged in a short time with natural disasters and human migration. Moreover, inequality exists no matter how well the economy is doing. During the summer heat waves of 2003, over 20,000 people died in Europe. Studies carried out in France found that the sick elderly aged over 75 who live in social isolation are at greatest risk, especially those who have lost autonomy and are living directly below the roof. Other vulnerable high risk groups include infants, the poor and homeless, and those with chronic or mental illnesses, alcohol consumption, prolonged physical exertion, and on certain chronic drugs."
"But with a thriving economy, the society can provide air-conditioners to high risk individuals." Peter argued.
"That would mean even more energy consumption, more carbon dioxide, and more air pollution," Philip said. "Elevated carbon dioxide levels can promote spore production of fungi. Dust particles can help deliver these allergens deep into our airways." Some scientists have in fact attributed the rise in incidence of asthma to global warming and environmental pollution.
"Higher temperature and stagnant circulation would also increase the concentrations of ground-level ozone and worsen smog. This would hurt those with cardiac and respiratory problems." George said. He is now perspiring all over his forehead in the heated argument.
"You should be concerned. You certainly look vulnerable to heat waves," Peter pointed at George's sweating forehead and joked. Nevertheless he finally agreed with the rest of the group that it's high time we took steps to combat global warming. Peter has a three-year-old girl with asthma.
Source: Quality HealthCare
