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Air quality is better than ever before
The quality of the air we live and breathe in, constantly evolves. It’s a complex theme that only seems to make mainstream news headlines when there is a problem, i.e. when a limit or warning threshold is exceeded. Measurement trends over the past few decades in Flanders show that the average annual concentrations of almost all air pollutants (ozone aside as it’s a special case) have decreased considerably. More importantly, the number of lost years of healthy life due to exposure to particulate matter (per population) has dropped by a factor of one and a half in the period 2005-2016. These facts seldom reach the news. Would a more nuanced interpretation of the full impact of the interaction of particulate matter, soot, ozone, sulfur and nitrogen (di)oxide on human health be too complex and, therefore not appealing enough?
Citizen science, according to the rules of science
In Antwerp, the launch of the wide-scale project ‘CurieuzeNeuzen’ has cast citizen science into the limelight. VITO can only applaud this development. Nevertheless, an ambitious project such as CurieuzeNeuzen not only offers opportunities, it also presents significant challenges. The involvement of twenty thousand volunteers has generated an enormous amount of high-resolution data. Data that scientists in other research projects can only dream off. This wealth of data must of course be validated, processed and communicated according to the rules of art (or better: of science). Only then can the participation of citizens in such projects be deemed worthwhile and may we begin to talk about the real successes of citizen science.
Each pollutant is unique
If you were to ask us who or what the main source of air pollution is, we could not provide a simple answer. When looking for the sources of air pollution, we must first make a clear distinction between the different pollutants. Anyone familiar with this subject knows that it is not easy to make a link between general air quality and individual sources.
In the case of sulfur dioxide for example, the main offenders are emissions arising from a few sites with heavy industry. On a map showing nitrogen dioxide concentrations, it’s the urban agglomerations and the road transport network that stands out. Not to mention the concentrations of ammonia, which only appear as hotspots in regions with intensive livestock farming (West Flanders, the north of the provinces of Antwerp and Limburg).
The dispersion of pollutants is strongly influenced by the weather, for which national boundaries do not play a role. The weather ensures for example, that (an estimated) three quarters of the total amount of particulate matter in the air of Flanders is imported: it blows in from our neighbouring countries.
Air and climate: two sides of the same coin
Climate and air quality are closely connected. An optimal environmental policy includes measures that are beneficial to both air quality (everywhere) and to the fight against climate change. Their relationship is complex and sometimes you have to look for the right win-wins.
- We know that sulfur dioxide, which can cause serious environmental and health damage, reflects the sunlight. As a result, the gas has a cooling effect and is therefore positive for the climate.
- Another example of this complexity is the decline of the diesel car in the vehicle fleet. As a result of the decrease of the number of diesel vehicles on our roads, less nitrogen (di)oxide and soot will be released into the air. Which is good news for the air quality. In the short term this trend will result in more petrol cars and thus higher CO2 emissions. A paradox with which not only policymakers are struggling, but also individual citizens who want to purchase a new car.
- Electric cars offer an answer in this transition, but they will not automatically solve the air quality problem.
