|MadSci Network: Environment|
?Aaron You asked if there is a difference between wood smoke and the smoke from burning leaves. Leaves and wood are both composed almost entirely of carbon, oxygen, hydrogen and nitrogen. When burned, leaves and wood give pretty much the same profiles in their smoke, except for whatever secondary products they may contain. The two most studied leaf smokes are tobacco and marijuana. They are very similar, except for the different drug found in each. The pollutants found, and the health and environmental problems of both leaf and wood burning are the gaseous products of combustion, water vapor, carbon monoxide, oxides of nitrogen volatile organic compounds and polycyclic aromatic compounds. The other major component is the fine particulates. All of these compounds can irritate the lungs, block the small air passages in the lungs and the volatile organic compounds and polycyclic aromatic compounds are carcinogenic (cause cancer). Many communities have banned open leaf burning and the EPA has adopted design standards for new wood burning stoves to reduce air pollution. Admin note: The wood that is burnt is generally stored for several months to dry it out. Dry wood burns at a higher temperature than damp wood and more of the carbon is converted to carbon dioxide. As a result, less particulates (which present a health risk) are produced. The burning of leaves is a seasonal affair and the leaves are not generally dried prior to burning. If leaf burning is allowed, it is possible to get many people adding a lot of particulates to the air in the same locality at the same time. This is not great for your health. In addition, it represents a waste of organic material, which could easily be converted to fertiliser through composting and returned to the soil. Instead, leaf burning adds carbon to the atmosphere which furthers global warming. Wood burning also creates carbon emissions, but at least it is being burnt for a better purpose than the leaves. Richard Kingsley, Mad Sci Admin
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