Zs. P. Komáromy szerk.: Studia Botanica Hungarica 16. 1982 (Budapest, 1982)

Hably, Lilla: The relation between Pb-pollution along mainroads and the trace element-composition in soil and vegetation (Examination of section rectangular to M3 mainroad)

S T U D I A XVI. BOTANICA HUNGARICA (Antea: Fragmenta Botanica) 1982 p. 5-40 The relation between Pb-pollution along mainroads and the trace element-composition in soil and vegetation (Examination of section rectangular to M 3 mainroad) By L. HABLY (Received November 30, 1981) Abstract: The thesis treats the lead pollution along mainroads and the trace element composition of Zn, Mn, Cu in the upper two meters of the soil as well as in vegetation living on it. It reveals a novel connection between pH, carbonate content, organic material content and soluble trace-element content. It shows not only the environment- polluting effect of the road, but also the regularity of the phenomena. The examinations were carried out in the Department of Petrology and Geochemistry at the Faculty of Sciences of Eötvös Loránd University in the course of 1980-81. Introduction On of the greatest problems of our time is environmental pollution. A significant role is played in this by lead, coming from the exhaust fumes of cars. Lead is harmful to every living being including humans. This metal gets into the atmosphere predominantly in the form of Pbtetraetile and Pb-tetrametile. The petrol used in Europe and in Hungary contains 0,4 g Pb/1. In Australia the Pb content of petrol is almost twice as much: 0.78 g Pb/1. It is obvious that pollution there is considerably higher, and the big industrial towns of Britain and of the USA are only slightly less polluted (Birmingham: 1700 ppm, Manchester: 940 ppm, USA: 1800 ppm on the average, considering dust alongside roads). It has been proved that this pollution may cause serious nerve and arterial diseases even a degeneration of muscles (BONTA et al. 1969). Its toxic effect has been detected in the simplest living organisms, in bacteria, and in plants of higher order. One per cent of lead caused fifty per cent inhibition in bacteria and fungi. In flowering plants (young barley) 35 mg/kg proved to be the highest critical level (DAVIS & BECKETT 1978). In fully developed plant tissues 10-30% Pb-level has been shown. Considering that lead accumulates in living organism i.e. it is not discharged from time to time even small quantities are extremely dangerous. It is an appaling fact that our normal daily diet contains 220-280 ug lead (DAY 1977). According to the data of the World Health Organization, the oral intake of lead by an adult person is even higher: 430 ug/day. To lead inhaled usually less significance is attributed in spite of its high adsorption. Thus, along roads, but mainly in cities that can play a significant role, too. Data from Australia show that the quantity of lead in dust along busy roads reaches 3100 ppm, medium traffic produces 1400 ppm, and alongside less busy roads it is 830 ppm. Even green belts contain considerable Pb-level. Thus in city playgrounds 700 ppm was measured, while in suburban areas only 40 ppm. The leadcontent in the dust of some busy roads reaches 5000-6000 ppm (DAY 1977). The effect of lead is