Heavy metals

Soil contamination by heavy metals, such as cadmium, lead, chromium, copper, zinc, mercury and arsenic, is a matter of great concern.

Heavy metals are present naturally in the soil, but their levels are increased by:

• industry (non-ferrous industries, power plants, iron, steel and chemical industries);

• agriculture (irrigation with polluted water, use of mineral fertilisers)

• waste incineration;

• combustion of fossil fuels; and

• road traffic.

Pollution of agricultural soils by heavy metals may lead to reduced yields and elevated levels of these elements in agricultural products, and thus to their introduction into the food chain.

Heavy metal deposits on grassland soils remain predominantly in the top few centimetres and are directly ingested with soil by grazing animals.

Heavy metals are toxic and inhibit the soil's microorganic activity. Their concentration in the soil can remain for decades or even centuries.

Reduction of heavy metal emissions is the most direct way to decrease the atmospheric deposition of these elements and their build-up in the soil. Despite the great increase in traffic, for example, a reduction in lead emissions has been achieved through incentives to use unleaded petrol.

Nevertheless, emissions of heavy metals from industrial plants in Central and Eastern Europe are still prevalent.

Implementing complex measures that reduce soil acidification could more efficiently reduce heavy metals. On agricultural land, heavy metal quantities can be decreased by using low-metal content resources for fertilisers, replacing inorganic pesticides with organic products, and other similar methods.