Pandemic restriction on movement leading to reduced pollution levels

Malta is currently experiencing a noticeable drop in pollution levels, which can most likely be attributed to preventive measures being taken in the battle against the COVID-19 pandemic.

When comparing the data from the Msida active air monitoring station (Data pre COVID-19 measures VS Data post COVID-19 measures) it is clearly shown that NO2 levels seem to have been reduced, most notably during the rush hour.

The Environment and Resources Authority (ERA) explained to this newspaper that a drop has most likely been a result of the reduced traffic in the area, however while this might be an easy conclusion to draw one should always note that such trends are to be studied over a longer time period.

A longer time frame is essential so that meteorological variations – among other variables – are considered, so as to provide a more accurate explanation for the reductions.

ERA has also urged the general public to show an interest in its initiatives, and to contribute towards the islands’ air quality in whatever way they can, both for the sake of the current generation and the ones that are yet to come.

ERA monitors ambient air, both actively and passively, by means of equipment set up in a number of sites around the Maltese Islands that checks for different pollutants according to the purpose of the monitoring location.

The findings are then used to develop policies to improve our air quality. The first type is ‘passive’ monitoring, which enables ERA to acquire trends on the basis of monthly averages. To get this information, ERA manages a network of diffusion tubes, which are small and practical monitoring devices that use an absorbent medium to indicate chemical presence in the air during the monitoring period.

Spread across rural and urban parts of Malta and Gozo, ERA officials replace these tubes every four weeks before they analyse the tubes in a laboratory. At the moment, there are 100 sites around the Maltese Islands whereby diffusion tubes monitor nitrogen dioxide (NO2) and volatile organic compounds (VOCs). Additionally, a smaller network of diffusion tubes spread across 24 sites monitors sulphur dioxide (S02).

The second type is ‘active’ monitoring, which is more advanced and necessitates the use of larger equipment. Through this, ERA is able to gather data in near real-time, with new information received every 15 minutes on average. Four such stations are strategically situated in different locations. One is in Msida, where traffic is at its heaviest, while another is in Żejtun, where it is set against an urban background. The third is in another urban site in Attard and, the fourth, in Għarb, Gozo, where it monitors air in a rural context away from polluting sources.

On top of this, ERA is currently in the process of setting up a fifth station, which will be placed in Xemxija. The idea behind this is to ensure better representation of the monitored zone, extending it from the outskirts of the main agglomeration in the harbour area all the way to north of the Island and Gozo.

These real-time stations are all in line with the requirements stated in the relevant EU legislations related to the monitoring of ambient air quality. As are the pollutants monitored, which are namely ozone (O3), S02, nitrogen oxides (NOx), carbon monoxide (CO), volatile organic compounds (VOCs), gaseous mercury (Hg), and particulate matter (PM10 and PM2.5). Meteorological variables are also monitored at each site, as these have an effect on air quality.

Moreover, throughout recent years, several measures have been taken to reduce concentrations of pollutants like benzene (C6H6) and SO2.

Environment Minister Aaron Farrugia said that this data is indicative of the impact human activity has on air pollution, and that it would be good for everyone to do their part to contribute towards cleaner air in the future.

“While this is not the time to be focusing on matters that are the result of such a devastating pandemic and, and while we do need to be focusing on the health of our relatives and protecting our economy, I am determined to see that after this period is over, everyone is made more conscious of the impact of human activity on our environment.

“We can use this time to educate our children more about how we can take care of our environment. As adults, we should work towards a cultural shift for less use of private cars, more remote work, and more efficient waste separation efforts,” he said.