Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter.

Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter C) on an yearly and a monthly basis.

A PM10 chemically characterized nation-wide dataset for Italy. Geographical influence on urban air pollution and source apportionment.

Urban textures of the Italian cities are peculiarly shaped by the local geography generating similarities among cities placed in different regions but comparable topographical districts. This suggested the following scientific question: can different topographies generate significant differences on the PM chemical composition at Italian urban sites that share similar geography despite being in different regions? To investigate whether such communalities can be found and are applicable at Country-scale, we propose here a novel methodological approach. A dataset comprising season-averages of PM mass concentration and chemical composition data was built, covering the decade 2005-2016 and referring to urban sites only (21 cities).

Seasonal and Spatial Variations of the Oxidative Properties of Ambient PM in the Po Valley, Italy, before and during COVID-19 Lockdown Restrictions.

This study describes the chemical and toxicological characteristics of fine particulate matter (PM) in the Po Valley, one of the largest and most polluted areas in Europe. The investigated samples were collected in the metropolitan area of Milan during the epidemic lockdown and their toxicity was evaluated by the oxidative potential (OP), measured using ascorbic acid (OP) and dithiothreitol (OP) acellular assays. The study was also extended to PM samples collected at different sites in the Po Valley in 2019, to represent the baseline conditions in the area.

Seasonal and Spatial Variations of PM and PM Oxidative Potential in Five Urban and Rural Sites across Lombardia Region, Italy.

Oxidative potential (OP) of particulate matter (PM) is gaining strong interest as a promising health exposure metric. This study investigated OP of a large set of PM and PM samples collected at five urban and background sites near Milan (Italy), one of the largest and most polluted urban areas in Europe, afflicted with high particle levels. OP responses from two acellular assays, based on ascorbic acid (AA) and dithiothreitol (DTT), were combined with atmospheric detailed composition to examine any possible feature in OP with PM size fraction, spatial and seasonal variations.