Rhinitis-related symptoms are on the decline in young teenagers, a study has found, possibly due to the Marsa power station being phased out and higher quality fuel used in cars.

The incidence of rhinitis – whose symptoms include sneezing and a blocked or runny nose – fell by a third in 2012 when compared to similar studies carried out in 1995 and 2002.

In girls, the prevalence fell from 55.7 per cent in 1995 to 28.8 per cent and in boys from 49.2 per cent to 33.16 per cent. These figures, however, are still considered high.

Martin Balzan, a consultant respiratory physician at Mater Dei Hospital who led the EU-funded study named Respira, said the decline in rhinitis-related symptoms could be attributed to the fact that the Marsa power station was being phased out and to the better quality of fuel for cars compared to 10 years ago. The study, which looked into the respiratory health of children, was launched in March last year and involved more than 1,000 11 to 14-year-old students at secondary schools in Cospicua, Ħamrun, Żejtun and Mosta. It included questionnaires, clinical tests and air-monitoring at schools and homes.

The research found asthma-related symptoms among boys had gone up slightly, although it is not sure whether this is related to increased prevalence or better diagnosis.

In monitoring the air, the study found a high presence of suspended particulate matter, referred to as pm2.5, which is the fine dust seen in sunlight.

“Wherever we went, the pm2.5 was high especially when children enter classrooms,” said Dr Balzan. “We found high levels of pm2.5 and nitrogen dioxide both outside and inside schools, to varying degrees at all schools.”

“We found a high concentration of heavy metals in the outdoor areas in Ħamrun and Cospicua but insignificant levels in Mosta. The likelihood is that this came from the Marsa power station,” said Dr Balzan. ­­­“We have also found large amounts of sulphur which is emitted from power stations and car diesel, but Enemalta is meant to be buying low-sulphur diesel,” he added.

When contacted, Philip Borg, manager of the Petroleum Division, said Enemalta used low-sulphur fuel oil for power stations.

He said there was a time when the corporation used fuel oil with 3.5 per cent of sulphur content but by 2005 this had already decreased to one per cent and nowadays both power stations used fuel oil at 0.7 per cent.

A spokeswoman said all of Enemalta’s emissions were below the limits stipulated in EU directives.

When it came to car emissions, Ing. Borg said fuel was bought according to a set standard and both Malta’s diesel and petrol had ultra-low sulphur content.