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[CAIRO] Two groups of Egyptian scientists have reported that algae can remove toxic heavy metals from soils and potentially clean up oil spills by 'feeding' on them. They hope that such algae could provide a cheap, eco-friendly way of removing toxic pollutants from the environment.

The researchers presented their findings at an international conference on environmental challenges facing Egypt, held in Cairo in the first week of June.

Rawheya A. Salah El-Din from Egypt's Al-Azhar University described how, when grown in the presence of lead, cadmium and cobalt, a type of algae called Microcoleus steenstrupii removed between 75 and 81 per cent of the three heavy metals. The alga is native to Egypt and was isolated from salt marshes there.

High concentrations of these metals caused reduced germination rates and plant height in both beans and wheat. But Salah El-Din reported that adding algae to the soil stimulated plant growth and retarded accumulation of the toxic metals in the plants' tissues.

Presenting a separate paper, Gamila Hussein — a biologist at the Water Pollution Research Department of the National Research Centre in Cairo — described how a number of other microscopic algae species that occur in the River Nile can grow on crude oil. They break down the oil and release carbon dioxide and water, but retain two key classes of polluting chemicals, called n-alkanes and polycyclic aromatic hydrocarbons.

According to Hussein, these algae have potential to decontaminate areas affected by oil spills. In contrast, conventional clean-up methods are costly, difficult to implement and result in industrial waste.

Yahia Abdel-Jaleel Mahmoud, a microbiologist at Egypt's Tanta University, told SciDev.Net that these research findings are "important steps in the identification of a natural, simple, effective, fast, cheap, safe, and long-term technology for reducing heavy metal pollution and the remediation of crude oil contaminated sites".

He suggests that genetically modifying the algae might enhance their ability to bind with and break down toxic chemicals found in oil. And he highlights the importance of such approaches in the Middle East. For example, approximately eight million barrels of oil were spilled during the 1991 Gulf War, and oil spills resulting from destruction of oil tankers, wells and pipelines are still frequent in Iraq.