Hidrológiai Közlöny 1971 (51. évfolyam)

1. szám - Dr. Bolberitz Károly: Természetes vizekben előforduló mikroszennyező anyagok fajtái és hatásai

Hidrológiai Közlöny 1971. 1. sz. 31 The kinds and effects of micro-pollutants encountered in natural waters Dr. BOLBERITZ, KÁROLY Department Head Public Health Institute, Budapest The most important problem in pollution control is that of micro-pollutions. Recent attention has been directed towards this problem for two reasons, of which the first is that of quantities. Substances known long ago to be present in low concentrations in waters draining from industrial regions, such as phenole derivates, mineral oil, heavy metals originating from metál plating shops, etc., occur now with increasing frequency at an increasing number of places. Even if it is assumed that such unwanted and dangerous wastes are treated with good efficiency, practically this operation is never perfect, small quantities of the polluting material, called micro-pollution is always left behind. Under such conditions it is of considerable interest to know the number of sources and especially the volume of wastes originating in a particular area or along a watercourse where such micro-pollution has been observed. At present both the number of sources and the volume of wastes show an increasing trend, the direct consequence of which is that pollutants, which were considered harmless not long ago present already a hazard to public health and will even more so in the near future. The same applies to certain pollutants originating from transportation, but alsó from households, which are encountered with growing frequency over growing areas. The other reason is related to quality. A shift towards extremes is made possible, and is even favoured by the rapid advances of science and technology. Engine speeds have increased tremendously in the machine industry and transportation, extreme temperatures and extraordinary pressures are becoming common in power stations and in the chemical industry, mention must be made of the metals melting at very high temperatures, liquid gases approaching the absolute zero temperature, alloys approaching the hardness of diamond, plastics resisting practically all chemical effects, or photographic material of phantastic sensitivity. In the chemical industry, which is of paramount interest in this respect, this striving for extremes has resulted in the production of chemicals that are as specific and as effective as possible. The first signs of this process became apparent in the pharmaceutical industry, whence it spread to the production of plastics and detergents, while it culmiated in recent decades in the research and production of a variety of substances used for weed and pest control (pesticides). Concerning micro-pollutions, these latter are of primary importance, being substances of extreme biological effects, since they may altér fundamentally even in micro-concentrations, the natural balance prevailing in the environment, they may accumulate within the humán organism and become thus detrimental to health. . Of course, the vast strides of science and technology in the directions outlined before, and the utilization of the result in industry, transportation, agriculture, everyday life, etc., is accompanied by considerable advantages, which would be very difficult to sacrifice and which are almost prerequisites to humán existence on Earth. Reference is made in this context to agricultural production, which could produce only a fraction of the present output without pesticides, herbicides and fungicides and last, but not least fertilizers. Without rodent control vast crops would be lost annually. Mosquito control has effectively checked the spreading of malaria in civihzed areas, but insect control has played similar roles all over the World. The advantages offered by the advances of science cannot be sacrificed, these enabling us to ensure the essentials for the exploding population and to offer the comforts of civilization to it. However, all these qualitative and quantitative measures of interference in the order of Nature entail effects of an opposite sign, unwanted consequences as well. The majority of the substances that are harmfull even in micro quantities is discharged directly together with the wastes into the recipient watercourses, while others will enter indirectly through the ground, or groundwater and may even be carried by precipitation. Somé pollutants are introduced on purpose into waters, for instanee chemicals for mosquito- and aquatic plánt control, but sometimes very large quantities may be introduced into the water, soil, or atmosphere by accident. In these eases micro-pollution may turn into disastrous macro-pollution. It follows from the foregoing paragraphs that the greater the quantities produeed from these dangerous substances and the wider the fields in which they are used, the graver and of longer duration the resulting pollution of surface waters will be and the greater the hazards which they represent. Confronting these facts with the necessity of relying increasinglv on surface waters for domestic supply it will become readily evident, why the problem of micro-pollution assumes a growing significance from day to day. In spite of the great interest, which this subject is receiving all over the World, no uniform definition has been formulated as yet for the concept of micro-pollution. In ray belief the interpretation by the sense of the word is most correet in this respect, according to which this group comprises all pollutions and pollutants, that is foreign substances of detrimental effect, which may adversely affect, either directly or indirectly, even in concentrations of the order of micro-grams/litre, the enjoyability of drinking water, or which may be detrimental to health if the water is consumed for extended periods of time. For this definition the source of pollution