Black, gritty dust that covers roofs and yards in Tarxien and surrounding localities remains a mystery as Enemalta insists it is not emitted by the Marsa power station.
It is not clear what is causing this dark dust, however, the Malta Environment and Planning Authority was carrying out tests and results were expected in the coming weeks, a spokesman said.
Hopefully, the results will answer the question residents have been scratching their heads over: What is this dust?
Following two years of inconclusive tests, Mepa will be comparing dust collected from roofs to samples taken from the power station's chimneys. This comparison follows a string of complaints by residents in areas around Marsa.
Earlier this week, Tarxien mayor Paul Farrugia called on the authorities to stop the power station from releasing the dust he said was detrimental to residents' health.
Mr Farrugia said the power station's emissions had been held in check for the past years. However, a few weeks ago, the dust reappeared and was covering yards and roofs in Tarxien and surrounding localities.
Following his statement, residents in other localities also voiced their concerns and described the dust as "gritty". Complaints came in from Fgura, Paola, Żejtun and Żabbar.
Enemalta said yesterday it regularly monitored dust emissions from the power station's chimneys.
Emissions remained consistent over the past six months and were well within the stipulated limits, it insisted.
Moreover, the spokesman said the dust from the power station's chimneys was fine, not "gritty". "If there were any heavy particles, they would drop close to the chimney not be carried towards Tarxien... As anyone can see, just by looking at the chimneys, there are no clouds of black smoke being emitted by us," Enemalta said.
A Mepa spokesman said the authority had been trying to determine the nature of the dust for about two years. However, results were always inconclusive. Now that fresh complaints had been made, it would be taking samples from roofs and the chimneys to compare the chemical make-up.
Asked why no clear results had been obtained for so long, the spokesman explained it could be because the dust was caused by a number of different pollutants. However, he stressed, this was not necessarily the case given the inconclusive results.
He added that, according to Mepa's air quality monitoring station in the area, there had been no significant increase in emissions recently. Mepa kept the health authorities updated on the matter.
In view of an EU health directive, the Marsa power station will have to be shut down by 2015. The time limit set is aimed at stemming emissions of hazardous substances that can adversely affect people's health.