Global Ecological Problems and Issues

Cooking energy is one of the basic necessities of the people. According to recent studies people can better utilize the energy and nutrients of cooked than of uncooked food. Two times more vegetable food or 50 per cent more meat is required to provide the same amount of nutrition for humans if the food is consumed without softening it first through the process of cooking.

Cooking energy is an important equality and democracy issue. It is also an issue where it is easy to see that inequality and lack of democracy are hurting everybody, and not only the poor.

A growing percentage of people can cook their food with electricity, natural gas or kerosene. However, about three billion people in the world use wood, straw and cow dung as the source of their cooking energy. About one quarter of the people who use fuelwood in cooking live in India.

Most people that use biofuels can only afford very primitive and poorly designed cooking stoves. Hundreds of millions of them cook their energy with a stove consisting of only a few stones. Such stoves have a very low thermal efficiency: they often waste 90 per cent of the energy content of the wood, while the best available designs only waste between 10 and 20 per cent. Thus they are a factor contributing to the loss of forests, other vegetative cover and biodiversity.

Also, the cooking technologies that the poor are forced to use produce huge quantities of small particles and other substances that are dangerous to peoples health. The mothers and children of the poor families receive the highest exposures of these harmful substances, but in the densely populated urban or semi-urban areas also the more well-off families are affected. Thousands and millions of small stoves producing large amounts of pollution can make the air very toxic for everybody living in the cities and other densely populated areas. In Kolkata at least 60 per cent of the people are suffering from chronic respiratory illnesses like bronchitis because of the air pollution produced by traffic, factories and cooking stoves.

The soot particles, carbon monoxide and nitrogen oxides produced by the cooking stoves also contribute to the problem of global warming. Nitrogen oxides produce ozone, which is a strong greenhouse gas and the carbon monoxide emissions slow down the break-down of methane in the atmosphere.

Studies have linked woodfuel smoke to an impressive number of ailments. They include acute respiratory illnesses like bronchitis and pneumonia (both among children and elder people); lung cancer and a number of other cancers; chronic lung ailments like asthma, chronic obstructive lung disease and emphysema (and the heart problems that are often related to such lung diseases); tuberculosis; severe coronary heart disease; adverse pregnancy outcomes like an increased risk of low birth-weight, stillbirth or neonatal death; eye diseases and anaemia.

A survey carried out in Jumla, a cold mountain district of Nepal, where the average indoor smoke levels are very high, reported an infant mortality rate of 490 per thousand, 335 of which were due to acute respiratory illnesses. The very high infant mortality rate in the area is most probably caused by woodfuel smoke. Studies made in western India have estimated that the exposure of pregnant women to fuelwood smoke increases the risk of stillbirths by 50 per cent. In Nepal 15 per cent of non-smoking women suffer from chronic bronchitis.

According to the World Health Organization the smoking of pregnant women doubles the chance of the children to be born under-weight. This, in turn, increases the babies' risk of dying during their first year of life by three or four times. There is no reason why the exposure to smoke from cooking would not cause similar damage to the unborn children as the smoking of cigarettes.

According to one estimate particulate air pollution from the woodfuel smoke is, in India, at least partially responsible from 900 000 to 3 600 000 deaths, annually. Another study has estimated, that outdoor air pollution in the Indian cities is responsible for 40 000 to 50 000 deaths, annually, while the smoke from the cooking stoves kills 2,2 million people in a year. If the mortality rates among the other three-quarters of the people who use similar fuels in their cooking are somewhat similar, the impact of the fuelwood smoke is one of the most important health problems in the world.

In China, where much of the cooking is done by small, flueless stoves burning mineral coal instead of charcoal, mineral coal is probably causing similar adverse health effects than the cooking of biofuels in open stoves has been reported to do. In spite of all this, it has been estimated that more than 99 per cent of the world's air pollution research and control expenditures concentrate in reducing outdoor air pollution - which is responsible for less than 40 per cent of the total worldwide human exposure to particulates.

One solution to the problem is to spread smokeless chulhas: if the stoves are equipped with a flue (chimney) through which the smoke can escape, exposure to smoke is greatly reduced. Such cooking devices can be made of clay or mud to reduce the cost, so that even the poorest families can afford them. Another simple solution is to improve the ventilation of the kitchen. According to Indian scientists a roof hatch with a size of one square metre that can be opened when food is being prepared can reduce the exposure to smoke by almost 90 per cent.

To increase the production of good-quality fuelwood might also be one of the easiest and cheapest ways to improve the situation. The worst alternative is to burn cow dung and very small branches and sticks. When the burning temperatures are low a lot of different toxic compounds are produced. Also the agricultural production suffers, because the cow dung would have a great value as fertilizer.

Proper firewood produces less smoke and less toxic compounds than cow dung or small sticks. Also, some trees are better suited for firewood than some other species. Their wood burns cleanly and produces only little smoke. Unfortunately, it is the poorest that are forced to use the worst firewood: the better fuelwood is often too expensive for them. The more extensive growing of high-quality firewood would be a partial solution to the problem.

In Finland studies have shown that it is very important to burn wood that has been properly dried. The dangerous particulate and carbon monoxide emissions from wood that has been drying in the sun over two summers are roughly one hundred times smaller than the emissions from burning wet wood. In the tropics the sun is much hotter than in North Europe, and the wood dries with a much faster speed. However, even in the tropics it takes some time before the fuelwood has lost most of its moisture content. Also the poor families should be given a chance to store, legally, larger amounts of woodfuel so that they can dry it properly before burning it. This will also reduce the amount of wood needed for cooking because a smaller percentage of the wood's energy content is wasted on evaporating the moisture. Nowadays the poor families often have to burn the wood almost immediately after cutting or collecting it.

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