Luchtverontreiniging, een globaal overzicht van het studiegebied [Air pollution: a global survey of the field of study]

Air pollution is defined as any substance in the air which has a negative or damaging effect on human wellbeing. It is not a new problem: historical examples are cited from as early as 1257. Sources of pollution fall into two classes, human and nonhuman. The latter consist of dust, sea salt, volcanic ash, etc. Air pollution of human origin is further divided into radioactive and 'normal'. The sources of the latter are: home heating, public utilities, industry, motor vehicles, and agriculture. These are discussed in order. Home heating is generally done by means of fossil fuels, which, especially if burning is not complete, can be highly polluting. The use of natural gas, a much cleaner fuel, is on the increase. Public utilities include electrical generating stations, garbage incinerators, etc. NO and NO2 are characteristic pollutants from installations of this type. Industrial sources vary too widely for easy summary. Motor vehicles are heavy polluters, especially those using the gasoline engine, which is highly inefficient. Laws are being introduced requiring antipollution devices on automobiles; however, the effect of these devices is to raise burning temperatures in the engine, thus producing greater amounts of NO and NO2. In The Netherlands, greenhouse heating forms a significant source of pollution. Reactions between pollutants occur in the atmosphere; for instance, that between hydrocarbons and nitrous oxide, which results in substances which irritate mucous membranes and damage plants. Dispersion of atmospheric pollution is not yet completely understood, but is in general influenced by temperature lapse rate. Apart from accidents releasing poisonous gases into the air, the day to day effects of heavy air pollution are very detrimental, including increased chances of lung cancer. Also, pollutants which settle on grass may be eaten by grazing animals and thus arrive in the food chain. In measuring pollution, it is not the average level that is important, but rather the intensity of the peaks, and their duration. In conclusion, the legal situation in The Netherlands is summarized, with emphasis on the provisions of the 1972 Air Pollution Law.