One of Zambia's mining firms says it has managed to reduce its sulphur-dioxide emissions by 55 percent to mitigate the environmental degradation in some residential areas near the mine, the Zambia Daily Mail reported on Monday.

Mining companies in the southern African nation's Copperbelt province have been accused of polluting the surrounding areas, including rivers due to their poor environment management practices.

Last month, a local court fined one of the mining firms after it was found guilty of discharging toxics into a river which was a source of water supply for locals.

Some environmental activists were concerned about the high levels of sulphur-dioxide emissions in some townships of Mufulira district from the mining firms.

But environment watchdog, the Environmental Council of Zambia (ECZ), said Mopani Copper Mines (MCM) had managed to reduce sulphur-dioxide emissions by 55 percent from 100 percent it used to emit into the air.

"The discharge of sulphur-dioxide emission into the atmosphere by MCM in Mufulira has reduced by 55 percent. The mining company has installed an acid plant which is able to capture 55 percent of the gas. This is an achievement in terms of mitigating environmental degradation," ECZ northern region manager Patson Zulu was quoted as saying.

According to investigations, the townships near the mine had not vegetation because the soil contains high levels of sulphur dioxide while houses had cracks due to mining activities.

Zambia was Africa's top copper producer and the mining industry was responsible for 70 percent of the country's foreign exchange earnings.

The Zambian government has told the mining firms to play an active law to protect the environment by putting in place effective management policies. Foreign mining companies operating in Zambia include London-listed Vedanta Resources Plc, Equinox Minerals, Glencore International AG of Switzerland and Metorex of South Africa, Non-Ferrous Metals of China.