Doctor says results of his study ‘outdated’, shows no link between HFO and cancer rates

Consultant paediatric oncologist Victor Calvagna has denied his dissertation had shown a link behind the fossil fuel used at the Delimara Power Station (DPS) and cancer rates, after his study was cited by many as proof that the power stations as it is in the present time is a hazard to the public because it increases the risk of cancer.

"I categorically deny this conclusion and there is no way that one can extrapolate the findings in my dissertation to the DPS," Calvagna said in a statement he issued to the media.

"My dissertation does not show a link with the fossil fuel used at the DPS and cancer rates."

Calvagna said his study had focused on the rates of cancer in the vicinity of Magthab landfill and the Marsa Power Station (MPS), two sources of environmental pollution, and how those rates vary with increasing distance from them.

"The results of this study showed that there were no statistically significant changes in the rates of cancer as one moved away from the Maghtab landfill. The same can be said for the Marsa Power Station except for the rate of change of lung cancer cases," Calvagna said.

His study however showed there was a "statistically significant decrease in lung cancer cases" as one moved away from the power station in Marsa.

He explained that what happened at the power station in Marsa could not be attributed to the one in Delimara as the primary source of fossil fuel used to fire the turbines at the MPS from 1974 to 1995 was and not heavy fuel oil (HFO).

"To make matters worse the coal was stored in the open air at the Menqa wharf where it was exposed to the elements with the result that particulate matter was distributed by the prevailing wind to the immediate surroundings," Calvagna said.

 "If one had to conclude that the MPS was the sole cause of the excess of cancers seen in that area than, because of the long latency period associated with the development of these cancers - 20 to 40 years - one had to incriminate coal as the fossil fuel most likely to have resulted in this excess."

Calvagna added that one also had to keep in mind that the area around the MPS is heavily industrialised, vehicular traffic is high, and the incinerator from St Luke's Hospital was in use at the time.

"These are all sources of environmental pollution that together may raise the relative risk of a person living in that area to develop lung cancer. The situation in Delimara and neighbouring Marsaxlokk is completely different."

Calvagna said the populations of the inner harbour area and Marsaxlokk may also differ in their smoking history, deprivation status and occupational history: "All of these are important in influencing the relative risk of cancer."

Moreover, he adds, the chimneys of the MPS were of inadequate height and were prone to fumigate and downwash smoke onto neighbouring densely populated areas. "The chimneys at Delimara are of suitable height and help to reduce environmental pollution by dispersal into the atmosphere," he said, adding that the two power stations were incomparable.

He reminded that it was only in 2002 that electrostatic precipitators at the MPS were refurbished. Until done, they had been ineffective in removing particulate matter.   

"This was never the case at the DPS. The MPS was not equipped with systems to reduce the emission of sulphur dioxide, oxides of nitrogen, ozone and carbon monoxide as is the DPS."

Calvagna insisted that the results of his study were now outdated and do not apply to the present situation. Since joining the EU in 2004 Malta had to stringently comply with the Air Quality Standards Directive.

"As a result Enemalta has had to commission a system of continuous monitors of emission data from every chimney of both the Marsa and the Delimara Power plants. The emissions have to be below stipulated EU levels and the emissions from each chimney can be monitored real time by the public on the Enemalta website. In addition, at the time of the above study the MPS supplied 52% of the electricity demand of Malta, Now, with the new 144MW extension of the DPS, the MPS supplies only 20% of the islands electricity demand," he said.