The real time air quality monitoring network is complemented by a passive diffusive tube network. The Environment and Resources Authority (ERA) has deployed 100 NO2 tubes and 100 volatile organic compounds (VOC) tubes throughout Malta and Gozo. The tubes are exposed for a period of 4 weeks (for a total of 13 exposure periods in one year) after which they are sent to a laboratory for analysis.  The annual averages can then be interpolated to provide pollution maps as follows:

NO2 levels in Malta 2014

NO2 levels in Malta 2015 

NO2 levels in Malta 2016 

NO2 levels in Malta 2017  

NO2 levels in Malta 2018

NO2 levels in Malta 2019

Benzene levels in Malta 2014

Benzene levels in Malta 2015 

Benzene levels in Malta 2016 

Benzene levels in Malta 2017 

Benzene levels in Malta 2018 

Benzene levels in Malta 2019