The explosion of LPG distributor and petrol that occurred last Friday in Rome has actually generated dioxins: This is what emerged from the surveys of Arpa Lazio (the regional agency that deals with environmental protection), which monitored the air quality following the fire that arose in via dei Gordiani, where a concentration of dossine-teq equal to 1 pg/m was detected3. The stake of plastics, therefore, caused the spread in the air of toxic substances.
In particular, the monitoring made between 4 and 5 July also found 0.1 ng/m3 by benzo (a) Pirene And 530 pg/m3 of polyclorobifenili (PCB).
At the moment, however, the situation seems to be back under control, also thanks to the intervention of the firefighters: the concentration of dossine-teq went down to 0.1 pg/m3, with the values of Benzo (a) pyrene than minors of 0.1 ng/m3. The agency is still analyzing the data relating to the remaining quantities of PCB and, in the meantime, the Prosecutor has opened an investigation to clarify the dynamics of the accidentfor which the hypothesis of a human error was opened during the exhaust operations of LPG From a tank to a tanker.
What the Arpa data on air quality mean
Following fire or serious explosions, theHARP It always intervenes to monitor air quality and evaluate the possible presence of polluting substances such as polycyclic aromatic hydrocarbons, PCBs or dioxins. At that point, the data are provided to the local authorities who, based on the results, evaluate which security measures adopt to protect the population.
This monitoring is carried out thanks to the use of a sampler which, in the case of the fire that broke out in Rome on 4 July, detected the following values:
- 1 pg/m3 of dioxins – teq (concentrations of equivalent toxicity)
- 0.1 ng/m3 by benzo (a) Pirene
- 530 pg/m3 PCB
But what do these data mean? The harp specified that, as regards the dioxinsthere is no regulatory reference: in the guidelines for air quality, however, the WHO estimates the concentrations of dioxins – teq in an urban environment around 0.1 pg/m3 (even if this value can vary according to the local environmental characteristics), while a value greater than 0.3 pg/m3 It indicates the presence of a source of localized emission.
These dioxins can be generated in the event that the fire also involves Plastic materials (PVC)metals that act as a catalyst (primarily copper) and particular temperature conditions. In general, however, with the term “dioxin” a group of 210 chemical compounds Polyclorinated aromatic, divided into PCDD dioxins and Furani PCDF.
On the basis of the results, therefore, the harp was able to confirm that the fire He actually generated dioxins.
Instead looking at the value of polycyclic aromatic hydrocarbons (IPA), generally the Benzo (a) pyrene It is the only compound for which the law provides for a limit value, set at an average annual concentration of 1 ng/m3. However, since it is an annual average, the agency specified that this value cannot be compared directly with the measured value following the fire in via dei Gordiani.
Also as regards the Polyclorobifenili (PCB) There are no regulatory limits: the WHO guidelines simply indicate that concentrations measures in the environment area can swing Between 3 pg/m3 (in non -industrial sites) e 3,000 pg/m3 (in industrial sites or urban areas). In the case of Rome, the value has reached a maximum of 530 pg/m3 PCB.
The current situation: recommendations to citizens
At the moment, however, the concentrations seem to have returned to the norm, also thanks to the intervention of the firefighters. In the survey between 5 and 6 July, the value of dossine-teq went down to 0.1 pg/m3while the concentration of Benzo (a) Pirene is <0.1 ng/m3. PCB values, on the other hand, are still in the monitoring phase.
In any case, after the first data provided by the agency, the Municipality of Roma Capitale provided a series of indications to citizenship, including:
- The ban on stopping near the area affected by the fire and, if necessary, exit only by using the devices of FFP2 protection.
- The obligation to deactivate ventilation systems (air conditioners, controlled mechanical ventilation, aspiring hoods) to avoid the entry of the unhealthy external area.
- The ban on using vehicles in the surrounding areas: Circulation with open windows or active ventilation systems can increase the risk of inhalation of irritants.
