Rome, pollution and lockdown. Magnetic analysis on PM filters

Caption
Magnetic hysteresis measurements on PM filters of the Lazio region. On the left, an almost undisturbed filter from a rural area, on the right, a filter from an area with intense vehicular traffic. The samples are related to the same day.

Caption
Magnetic hysteresis measurements on PM filters from the Lazio region. On the left, an almost pristine filter from a rural area, on the right, a filter from an area with intense vehicular traffic. The samples are for the same day.

Automotive magnetic emissions doubled on average in the period following the first lockdown (March 9 - May 18, 2020), as emerged from the magnetic analyzes carried out on the daily filters of the air quality control units in the areas of Rome with the greatest impact from vehicular traffic. This is the result of a study conducted by the National Institute of Geophysics and Volcanology (INGV) and the Regional Agency for Environmental Protection of Lazio (ARPA Lazio).
The work, recently presented at the General Assembly of the European Geosciences Union (EGU), is the result of the Convention stipulated between the two Organizations regarding the magnetic characterization of PM, and has further highlighted that non-exhausted emissions from vehicle brake abrasion constitute the main source of metallic pollutants in the urban area.

The results obtained in areas with intense vehicular traffic were compared with those relating to rural areas characterized by modest anthropic impact which, however, did not show significant magnetic differences between the lockdown and post-lockdown periods.

The impact of the lockdown on the concentration of atmospheric dust has been widely debated, since its generalized reduction has not been found, unlike what has been observed for gaseous pollutants and, in particular, for nitrogen oxides.
In fact, the weather conditions, the transport of natural dust from the Caspian Sea and the Sahara, which during the lockdown period caused concentrations even higher than 100 µg/m3, i.e. double the legal limit, as well as phenomena of resuspension of previously deposited dust to the ground, can cause high levels of atmospheric dust not directly linked to the primary sources of pollution.
In this sense, the magnetic analyzes carried out on the PM filters have provided original information useful for the differentiation between atmospheric particulate matter of natural and anthropic origin, particularly effective for recognizing the different contributions due to vehicular traffic emissions and for determining the impact of the measures more drastic than lockdowns on air quality.

This study fits into the context of the magnetic monitoring and biomonitoring of air quality developed at the Paleomagnetism Laboratory of INGV, aimed at providing useful tools for interpreting data on air pollution and, in perspective, functional to measures to be undertaken to reduce the environmental impact of man-made emission sources.

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Rome, pollution and lockdown. Magnetic analyzes on PM filters.

The concentration of the magnetic fraction of PM10 doubled on average in the period following the first lockdown (9 March - 18 May), as emerged from the magnetic analyzes performed on the daily filters of the automated air quality control units in the areas of Rome with the greatest impact from vehicular traffic. This is the result of a study conducted by the Italian National Institute of Geophysics and Volcanology (INGV) and the Regional Agency for Environmental Protection of Lazio (ARPA Lazio).
This work, recently presented to the General Assembly of the European Geosciences Union (EGU), is the result of the agreement stipulated between the two institutions regarding the magnetic characterization of the PM. It also highlighted that non-exhaust abrasion emissions from vehicle brakes are the main source of metal pollutants in urban contexts.

These results, obtained in areas with intense vehicular traffic, were compared with those relating to rural areas characterized by modest anthropic impact which, on the other hand, did not show any significant magnetic difference between the lockdown and post lockdown periods.

The impact of the lockdown on the concentration of atmospheric dust has been widely debated, as its generalized reduction has not been found, unlike that observed for gaseous pollutants and, in particular, nitrogen oxides.
In fact, the weather conditions, the transport of natural dust from the Caspian Sea and the Sahara, which during the lockdown period caused concentrations even higher than 100 µg / m3, ie double the legal limit, as well as resuspension phenomena of dusts previously settled on the ground, they can cause high levels of atmospheric dust not directly linked to pollution.
In this sense, the magnetic analyzes carried out on PM filters have provided original information, which is useful for the differentiation between atmospheric PM of natural and anthropogenic origin. This differentiation is particularly effective for recognizing the various contributions due to vehicular traffic emissions and for determining the impact of the more drastic lockdown measures on air quality.

This study is part of the magnetic monitoring and biomonitoring of air quality developed at the INGV Laboratory of Paleomagnetism, aimed at providing useful tools for the interpretation of data on atmospheric pollution and, in perspective, functional to the remedies to be undertaken to reduce the environmental impact of anthropogenic emission sources.