Author(s)

M. Momeni

Abstract

One of the harmful pollutants which affects sensitive ecosystems and indirectly finds a way into Man’s food cycle is lead. The factors involved in this process are: geographical features; certain industrial units; the heavy traffic of petrol-consuming vehicles along the streams of water. The Zayandehrood River is a major water source for the Esfahan region and it is obvious that any change in its ecology leads to a profound impact in the area as well as the life style of over three million inhabitants who entirely rely on this vital water source. This paper presents research into the variation of lead in a seven-year period (1997-2004). Using the experimental method, we have taken samples from different places of the river. Here, the changes in the lead of the water have been measured in the laboratory and the factors involved in the process have been discussed and analyzed as well. Based on some research performed, despite the omission of lead from petrol in 2001, the lead content of the river is insignificant – about 0.01 milligrams in a liter, while it rises to 96 milligrams a kilo in the sludge of the river bed. We come to the conclusion that the greatest part of the lead contamination of the river is the immediate result of the factory waste dumped in it or the waste materials which find their way into the river. To decrease or minimize the lead content of this sensitive ecosystem, this research also introduces some guidelines, the most important of which are: - To prevent the concentration and development of factories in the Zayandehrood Mid-basin. - To remove certain factories from the city limit, and, most importantly, - To direct all factory waste-materials to a duct to be purified thoroughly before dumping in Gavkhoni Marsh. Keywords: Zayandehrood, variation, lead, pollutant, ecosystem, industry, vehicles, river sludge.

Keywords

Zayandehrood, variation, lead, pollutant, ecosystem, industry, vehicles, river sludge.