Analysis of major pollutants and physico-chemical characteristics of PM2.5 at an urban site in Rome

Carla Fanizza; Barbara De Berardis; Federica Ietto; Maria Eleonora Soggiu; Roberto Schirò; Marco Inglessis; Marcello Ferdinandi; Federica Incoronato

doi:10.1016/j.scitotenv.2017.10.168

Analysis of major pollutants and physico-chemical characteristics of PM2.5 at an urban site in Rome

Sci Total Environ. 2018 Mar:616-617:1457-1468. doi: 10.1016/j.scitotenv.2017.10.168. Epub 2017 Oct 23.

Authors

Carla Fanizza¹, Barbara De Berardis², Federica Ietto³, Maria Eleonora Soggiu⁴, Roberto Schirò³, Marco Inglessis⁴, Marcello Ferdinandi⁴, Federica Incoronato³

Affiliations

¹ INAIL, DITSIPIA - Via R. Ferruzzi 38-40, 00143 Rome, Italy. Electronic address: c.fanizza@inail.it.
² Italian National Institute of Health (ISS), Centre of Innovative Technologies in Public Health, Viale Regina Elena 299, 00161 Rome, Italy.
³ INAIL, DITSIPIA - Via R. Ferruzzi 38-40, 00143 Rome, Italy.
⁴ Italian National Institute of Health (ISS), Department of Environmental and Health, Viale Regina Elena 299, 00161 Rome, Italy.

PMID: 29074245
DOI: 10.1016/j.scitotenv.2017.10.168

Abstract

Air quality data from a one year study at an urban roadside location in Rome are reported for major pollutants. Continuous concentration data of carbon monoxide, ozone, nitrogen dioxide, aromatic hydrocarbons and natural radioactivity were measured in the urban air of Rome from January 2016 to January 2017. Moreover, PM_2.5 mass concentration and physico-chemical characteristics of single constituent particles are herein reported. Gaseous pollutants, except ozone, and PM_2.5 showed maximum concentrations in December due to high atmospheric stability. O₃ and NO₂ trend analysis showed photochemical smog episodes in June and September. In September, during a photochemical smog episode the aromatic hydrocarbons contribution to ozone formation was experimentally proven. Pearson's coefficient among aromatic hydrocarbons and the ratio Toluene/Benzene (T/B) showed that pollutants were under the influence of vehicular traffic. Physico-chemical characterization of PM_2.5 single particles, carried out by field emission scanning electron microscope combined with energy dispersive X-ray spectroscopy, displayed the presence of particle diversity from natural and anthropogenic origin. Four principal components in the PM_2.5 were identified: carbonaceous particles, Ca-sulphates, soil dust and building structure particles, metal particles. The principal source of carbonaceous particles in this urban area consists of the motor vehicle exhausts and the heating systems in winter. Traces of S and sometimes S, Na, K were detected on varying percentages of carbonaceous particles. These data suggested that the carbonaceous particles act as vehicles for strong acids, prevalently H₂SO₄ and alkaline metal sulphates. A Saharan dust contribution to PM_2.5 was found in different periods. Metal particles included iron oxide particles, metals oxide particles and Fe-rich metal compounds. The identification of chemical composition of individual particles provide useful information to determine their origin and formation processes.

Keywords: Elemental composition; FESEM/EDX; Gaseous pollutants; PM(2.5) pollution; Photochemical smog.