Lisbon, Feb. 10, 2025 (Lusa) - The greater Lisbon region woke up on Monday morning to a strange smell in the air "with acrid/olive-like characteristics", similar to what happened last year, due to a south-easterly wind, according to an air quality researcher.
"Today we had a situation very similar to what happened last year, around this time, when we all woke up to this perception of an acrid/olive-like odour, which we believe may have its source in the olive pulp processing plants located further south, namely in the Alentejo area," researcher Sofia Teixeira told Lusa.
According to the specialist from the air quality department of the Faculty of Science and Technology at Universidade Nova de Lisboa, the perception is due to "very specific" meteorological conditions, in this case, "south-easterly winds, which immediately disperse the air masses and odour compounds to a more northerly area, such as Lisbon and the Tagus Valley".
Sofia Teixeira also explained that there was the addition of another phenomenon "of thermal inversion between midnight and nine in the morning, which resulted in what we call the helmet effect, in which these compounds are trapped in lower layers of the atmosphere and we can easily detect this smell with our noses, which was causing us some discomfort".
According to the Portuguese Environment Agency (APA), the situation of "weak dispersion in the atmosphere, combined with the occurrence of a weak wind from the southeast quadrant" led to concentrations of odourous compounds in the Greater Lisbon region, a situation that "improved in the afternoon", but which could "occur again tomorrow morning, but with less intensity".
According to the APA, the "continuous and real-time" monitoring of air quality at the network's stations "does not reveal any problems in terms of the pollutants measured with health effects", guaranteeing that it is "continuously overseeing air quality".
For the researcher, the concern is "only for the inconvenience" of the smell and the questioning of what you can do outdoors because you are perceiving the bad odour, however, she believes that the members of the public who are most exposed to the emitting sources should be studied.
"I think that would be important. We should study the communities that live or are most exposed, which are those that are close to these sources of odour. It would also be important for us to have some kind of regulation or guide that could guide academia, citizens or even the industries themselves on what can be done about this issue of odours," she stressed.
Sofia Teixeira pointed out that in Portugal there is "no framework in the air quality regulations" on this issue of odours, unlike other European countries that already have specific regulations on this matter, which could help minimise these impacts.
At the moment, as there is no legal obligation, the researcher said that "it's only through goodwill that some strategies or measures can be created to adjust production when the wind is blowing from a certain direction".
"But it's a bit down to goodwill and not what's in the regulations, or in a guide, or what has been studied and thought out for the type of industry in question, like other situations that happen in terms of air quality," she emphasised.
RCP/AYLS // AYLS
Lusa
