VietNamNet Bridge - The waste sludge may not only contains lead, but other heavy metals as well. Scientists have warned the problem would be very serious if the sludge reaches the environment.

 

 

The waste sludge may not only contains lead, but other heavy metals as well.

The lead & zinc waste tank in Pac Mieu Town of Bao Lam district in Cao Bang province unexpectedly broke down on January 5, releasing hundreds of thousands of cubic meters of water and waste sludge into the Gam River, having seriously polluted the river.

Vu Ngoc Luu, chair of Bao Lam district, said late last week that the damages caused by the incident remain unclear.

VnExpress quoting Pham Khang from the Nature & Environment Protection Association as saying that there is not only lead, but other heavy metals as well in the waste sludge, therefore, it would be very dangerous if the sludge is widely spread out in the environment.

If the lead concentration found in the sludge is not high, people should scoop up the soil and throw it away. They should also be warned against using water and examining food before use.

“Heavy metals, if mixed into water and soil, will cause the environment, harm living beings, including humans,” Khang said, adding that the damages the incident caused can only be measured depending on the volume of waste sludge and lead & heavy metal concentrations.

Explaining the possible effects to humans, Phung Chi Sy, an environment expert from the Hanoi University of Natural Sciences, warned that the sludge, lead and zinc, when reaching the environment, would be accumulated in vegetables, shrimp and fish which would harm people who eat the food. Meanwhile, the sludge, when mixed into water, would also harm people if they use the water for washing.

However, Sy reassured the public saying on Dai Doan Ket that the problem would not be too serious if the waste sludge only contains lead sulfite, because the substance is not soluble, and therefore, it can be collected with machines.

“Lead would be less dangerous if it is in the powder form,” he said.

Tran Hong Con from Hanoi National University agreed that if this is the sludge from the mineral ore exploitation process, the situation would not be serious, because the lead exists in lead sulfite, and is not soluble. If this is true, Con said, water pollution won’t occur.

However, Con warned that it would be dangerous if additional chemicals were used to make refined lead ore with higher concentration, while the danger levels would be different depending on the kinds of chemicals and the technologies applied.

When asked about the solutions to fix the tank breaking incident, Sy said that it will take long time to do this. If the lead concentration found in the sludge is not high, people should scoop up the soil and throw it away. They should also be warned against using water and examining food before use.

Dai Doan Ket