Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

R Caggiano,S Sabia,S Trippetta

doi:10.5194/nhess-15-325-2015

Abstract

Abstract. The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy), about 30 km away from the study area along the north direction. The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6–12-month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6-month and 12-month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

Highlights

The growing interest aroused by atmospheric pollution is due to its impact on human health, air quality and global climate change (IPCC, 2013; Kulmatov and Hojamberdiev, 2010; Pope III and Dockery, 2006)
Principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts
The study presented highlights that the accumulation capacity of the lichens in relation to the analyzed trace elements is different and that the used lichen species are suitable for biomonitoring investigations

Summary

Introduction

The growing interest aroused by atmospheric pollution is due to its impact on human health, air quality and global climate change (IPCC, 2013; Kulmatov and Hojamberdiev, 2010; Pope III and Dockery, 2006). In this field, atmospheric particles play a key role because they may contain high concentrations of several trace elements known to have toxic effects on human health and environment. The monitoring of the trace element-related atmospheric pollution is a very complex problem due to a variety of reasons: the great number of potentially dangerous substances, the difficulty in estimating bioavailability, the large spatial and temporal variations of the pollution phenomena, the high costs of the recording instruments and the low sampling density of a purely instrumental approach (AchoteguiCastells et al, 2013; Wolterbeek, 2002)

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Conclusion