Enemalta this evening defended itself from allegations of responsibility for black dust, believed to be soot, found over the southern parts of Malta and pointed out that public reports indicated that dust samples collected from Fgura by MEPA did not contain nickel or vanadium, clearly indicating that its source did not relate directly to the power station.

Reacting to a press conference by Opposition environment spokesman Leo Brincat, Enemalta said Mr Brincat had referred to a study conducted in 2000 that attempted, without any definitive conclusion, to determine causes of black dust in certain parts of Malta.

"The study is hardly relevant to today's situation. Over this time the fuel used by the Marsa power station has been improved and emissions have been reduced by about 80% since then. In addition all stacks at the power stations have since been equipped with continuous emissions monitoring equipment."

Enemalta said that Mr Brincat had failed to mention that there were numerous other possible sources of black dust such as the combustion of fuel, other than at the power station, such as the Marsa incinerator, vehicular traffic, ships ferrying in and out of the harbours, bakeries and industrial boilers among others.

The spokesman also failed to explain why there appeared to be no correlation between wind patterns and the finding of this dust, especially when considering that the Marsa power station's operation was not intermittent.

"Mr Brincat is also wrong when speaking about the new plant in Delimara. The dust collected from the filters of the new plant will be collected directly in containers and exported for disposal or recycling. 95% of this dust is non-hazardous," the corporation said.

"The references made to the Delimara extension, that is yet to be developed, with black dust experienced intermittently over the past several years, is baseless."