Updated 5.52pm with ERA explanation below - Air quality monitors recorded no spike in pollution during last month’s landfill fire, raising concerns about the system’s accuracy.   

But the Environment Authority (see below) insisted that there was no pollution because of meteorological conditions. It also stressed that its monitors are well calibrated. 

Government sources said a request for the air quality readings had been made by the Environment Ministry after waste from black and grey bags had caught fire at the Wasteserv plant in Magħtab. 

The fire had prompted a public health hazard alarm with large swathes of the island put on alert by the health authorities about the possible impact of the fumes.

The government sources said they were surprised how no special air monitoring had been carried out in the area after the fire, which had covered several localities in a dark cloud. They were even more concerned about how the established monitoring centres had shown normal readings for the entire day.

“The concern is that if there is a major air pollutant in the central area of the island, this would not be recorded. If a fire of this magnitude can happen and there is no record, what about other sources of pollution? Are our readings for air quality a real picture of what is going on?” one source asked. 

Results of batches of tests have not yet been passed over to the government

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Another source said one batch of air pollution readings had in fact registered a spike, however, when the wind direction was factored in it did not appear that the source was the Magħtab fire after all.  Further testing for colourless volatile pollutants, the sources added, had been ordered. However, the results were not yet available.

The public had been urged to wash all fruit and vegetables before consuming, processing or cooking them, following the major blaze.

Soil samples had been taken from the worst-affected neighbourhoods. Samples of ash that rained down ­were also sent for testing, however, the results of both these batches of tests have not yet been passed over to the government.

Shortly after the fire, the Environment and Resources Authority had said it would be engaging “international experts” to conduct a series of tests to check, among other things, for dioxin and furan levels.

“These persistent organic pollutants will be tested for because they are usually present when plastic burns at a low temperature,” ERA had said.

Environment Authority explains

In an explanation following publication of this article, the Environment and resources Authority explained that the plume from the fire was ejected to such a height that it was clearly visible from all over Malta and Gozo. Due to the meteorological conditions on the day of the incident, there was very little mixing in the vertical direction with the air closer to the ground.

"This means that the effect of the plume on the air being monitored at ground level concentrations were likely to be insignificant."

It said the increase in pollutant concentrations recorded by ERA’s monitoring stations,was indeed recorded during the morning rush hour and was not any different from the peaks recorded on days preceding the incident.

It stressed that its instruments are in line with the requirements and standards requested by the European Union, regularly checked, calibrated and upgraded.