The citizens of six Portuguese cities are breathing air with pollution levels in excess of the fresh air standards set by the World Health Organisation.
Half of the dozen Portuguese cities analysed in 2014 by the WHO failed two tests of airborne pollution and one municipality failed both.
In the Algarve, Albufeira and Faro exceeded the 10 micrograms per cubic metre limit stipulated by WHO for fine particles, or PM2.5.
If the evaluation had been made using the less demanding European Union limit of 25 micrograms per cubic metre for PM2.5 the Algarve would have been in the clear.
Air pollution is caused by particles that can enter the respiratory tract, and are, according to the WHO, a health risk that increases mortality from respiratory infections, cause diseases such as lung cancer and cardiovascular problems.
The WHO database gathers information on 3,000 cities from 103 countries and when these figures are compared with 2008, the air pollution in urban areas has increased overall by 8%.
As for second test for inhalable PM10 with a limit of 20 micrograms per cubic metre, Albufeira only just avoided being listed with its 19 micrograms per cubic metre.
However, according to the European rules for PM10, where the limit is a higher 40 micrograms per cubic metre, all Portuguese cities tested by WHO would have passed the test.
Francisco Ferreira of the Faculty of Science and Technology at the Universidade Nova de Lisboa, an expert on air quality, warned that these values were obtained in measuring stations in city outskirts so city centres inevitably would have had higher readings due to traffic or industrial activity.
The expert said that "in several countries, including Portugal, the pollutant that is becoming more problematic is nitrogen dioxide" with the Algarve showing no unduly high levels.
The Algarve has little industry so its air pollution comes from vehicle emissions with the number of cars increasing dramatically in the summer season as tourists flock to the region.
