Young people during the heatwave last July in Barcelona Quique García (EFE)
The heatwave made July a black month for pollution in Barcelona. It’s not that high temperatures alone increase pollution: the point is that the heat and lack of wind preventing spread and African dust are exacerbating transport emissions, which are already increasing after the pandemic halted mobility and activity had recovered. This is what the monthly report of the information portal Contaminacio Barcelona points out: “In July, compared to 2021, a significant increase in pollution was registered for all evaluated pollutants”, that is nitrogen dioxide (NO2, 38.9 micrograms per cubic meter in the stations nearby). traffic), PM10 particles (32.5 micrograms in the same stations) and ozone (the negative health value was exceeded at one or two measuring stations for a total of ten days).
There is also another significant fact: in July there were eleven days of preventive warnings for high exposure to PM10 (particulate matter), “one day more than all registered if you add the years 2020 and 2021”. In six months, the city has already accumulated 35 days of warning, more than three times the amount in two full years, when there were only 11 days of warning, the report said.
July, coinciding with the heat wave, was a particularly negative month in terms of ozone pollution, a gas that, in contact with polluting emissions, produces particles that affect health, especially in the respiratory tract. For ten days, the value considered negative for health (an average of 120 micrograms per cubic meter for eight hours) was exceeded at one or two measuring stations in the city. So far this year, the levels have been exceeded 35 times, including 20 times in July, the report reports. The Fabra Observatory station has recorded 17 passes and the Vall d’Hebron station has recorded nine.
CSIC researcher Xavier Querol underscores the idea that the pollutant levels achieved in July were not due to the heat but “the combination of a heatwave and the return of air, vehicle and cruise traffic”. “In a heatwave without emissions, there would be no pollution,” he clarifies. However, it emphasizes that it is important to understand that the effects of heat waves are not limited to the increase in temperature, which leads to greater mortality and fire risk.
Ozone pollution is created by a chemical reaction when gases such as nitrogen dioxide or volatile compounds are oxidized, both of which are present from traffic in cities, Querol explains: “Ozone oxidizes pollutants and it creates more particles, which add up to African dust in the heat wave.” . If not dispersed above, these particles will accumulate and “burn” and aggravate breathing problems”. The particles produced, he adds, went up the course of the Besòs river towards the Montseny massif and reached Vic, a plain where there are usually large concentrations of ozone (due to the emissions rising from the Barcelona area and also due to of the ammonia it contains is manure from pig farms).
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The researcher clarifies that despite the negative data, the ozone measured this year is far from the indicators of the heat waves of 2003 or 2015, when traffic emissions were higher than the current ones. “It’s reduced because we put our batteries in,” he says happily.
Beyond the July records, the Contaminació Barcelona report warns of last year’s increase in pollution. The NO2 values in the four measuring stations close to traffic averaged 40 micrograms per cubic meter over the last 12 months (they are 39.4 micrograms). 40 is the maximum set by European legislation, but the World Health Organization (WHO) is more demanding, lowering it to 10. Of the four monitoring stations, the average over the last 12 months does not comply with the law, exceeding 40 micrograms in the Eixample at 43.5 micrograms each Cubic meter. The report calls this station “the mine canary,” which warns of unbearable levels, “the situation on the city’s busiest streets.”
Over the past 12 months, PM10 particles have shown an upward trend, exceeding WHO reference levels but below those set by European legislation. Regarding the concentrations of smaller particles, PM2.5, the report warns of a further increase and due to their impact on health requires a larger network of monitoring stations and updated data (the last one is from March).
From the city council, the councilor for climate emergency, Eloi Badia, evaluates the report that “the data must be analyzed in a longer context”. Aware of the pollution problem and that the data is deteriorating as the city returns to normal mobility after the pandemic, the Council points out, pointing out: “The City Council is aware of the situation and is proceeding with the measures that they minimize. Just this week we started work on the Superilla del Eixample, an ambitious project to drive cars out of the city and improve air quality.”
Grants for installing windows to isolate floors from traffic or nighttime noise
Barcelona City Council will subsidize the installation of soundproofing windows in residential buildings in areas with the greatest noise pollution at night or due to traffic. The subsidies, which are estimated at a total of one million euros this year, can be applied for from September, the climate emergency council Eloi Badia announced on Thursday. They pay up to 3,000 euros per floor, they have to apply for entire districts. The reason for this is that the replacement of windows is done in an entire facade to comply with the Urban Landscape Ordinance.
Families living in the special regime acoustic zones (ZARE), those affected
B. by traffic noise (zones C3, such as the streets of Aragó or Balmes) and also the recently created zones with noise pollution at night (ZATHN).
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