Air: particulate matter concentrations

Do particulate matter concentrations meet EU air quality standards?

Particulate matter (PM) consists of very small, suspended solid or liquid particles, deriving mainly from fuel combustion in transport and power generation, quarrying and construction dust, mechanically generated dust, tyre and brake abrasion, and aerosols of transboundary origin. It also includes natural sources such as atmospheric sea salt and wind-blown dust.

In 2009 Malta’s real-time monitoring stations indicated high levels of PM10, although they are partly from natural sources.

The EU daily limit value of 50µg/m³, which should not be exceeded more than 35 times a year (approximately 10 per cent of days measured), was exceeded on 57 out of 313 days measured (18.2 per cent of days measured) at Msida, the site most dominated by traffic.

The urban site in Żejtun recorded exceedances on 22 or 6.9 per cent of the days measured. At Għarb the threshold was exceeded on 10 per cent of days measured (14 out of 133 days), and the highest concentration for 2009, of 233.5µg/m³, was recorded in this locality.

Following analysis at Żejtun, it emerged that nearly all the exceedances at this station were due to natural sources. This enabled a revision of the Msida exceedances, whereby days with common exceedances due to natural sources at both sites were deducted, hence leaving Msida with 35 exceedances. There were more exceedances in 2009 than in 2008 due to improved data capture. Malta is in line with EU standards with regard to PM2.5.