Dissertation is quoted out of context - Dr Calvagna
Dr Victor Calvagna disagrees with the quoting of his dissertation, as being proof that the Delimara Power Station is a hazard to the public because it increases the risk of cancer. The dissertation has been used by sectors of the local media and political parties to back their points on the issue.
However, Dr Calvagna feels that there is no way that one can extrapolate the findings in the dissertation because of a number of reasons.
The findings in the dissertation relate to two point sources of environmental pollution, the Maghtab landfill and the Marsa Power Station. In his dissertation Dr Calvagna looked at the rates of cancer in the vicinity of these two point sources 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 and the same can be said for the Marsa Power Station, Dr Calvagna concluded.
The data cannot be extrapolated to the Delimara Power Station, Dr Calvagna thinks, because the primary source of fossil fuel used to fire the turbines at the Marsa Power Staton during the years of study was coal and not heavy fuel oil as is at the Delimara Power Station.
Furthermore the coal was at the time 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.
Moreover, Dr Calvagna stressed, if one had to conclude that the Marsa Power Station was the sole cause of the excess of cancers seen in that area than one had to incriminate coal as the fossil fuel most likely to have resulted in this excess.
However, even this conclusion may be biased since the area around the Marsa is heavily industrialised, 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 Marsaxlokk is completely different.
Furthermore the differences in the populations of the inner harbour area and Marsaxlokk as compared to the ones used in the study importantly influence the relative risk of cancer.
Dr Calvagna lists other differences that exist between the two plants. The chimneys at the Marsa Power Station 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.
The Marsa Power Station was not equipped with systems to reduce the emission of sulphur dioxide, oxides of nitrogen, ozone and carbon monoxide as is the Delimara.
Dr Calvagna concludes that the results in his study are now outdated and do not apply to the present situation because 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. In addition, at the time of the above study the Marsa Power Station supplied 52% of the electricity demand of Malta, while now due to the extension of the Delimara Power Station, the Mara plant supplies only 20% of the islands electricity demand.