Spatial Series and Multivariate Analysis in Assessing the Essential (Cu and Zn) and Toxic (As, Cd, Cr, Co, Hg, Ni and Pb) Metals Linked with Health Risk and Ecological Effects of Atmospheric Deposition by Using Bryophyte Moss as Bioindicator

Abstract

Toxic metals are among the main threats to environmental pollution as they pose risk to the human health via different exposure pathways and to the environment. This chapter is focused on spatial series and multivariate analysis in assessing the toxic metals linked with health risk (As, Cd, Cr, Co, Hg, Pb, Ni and Zn) and ecological effects of atmospheric deposition by using mosses as bioindicator. It is based on the concentration data onto eight elements in moss samples collected during the 2015 moss biomonitoring survey conducted at the same time with the European moss biomonitoring. The elements under investigation were determined by ICP-AES and CVAAS (only Hg) analytical techniques performed in the Institute of Chemistry, Faculty of Science, Ss. Cyril and Methodius University, Skopje, North Macedonia, and Faculty of Natural Sciences, University of Tirana, Albania. Hypnum cupressiforme (Hedw) spp. have been used as bioindicators of trace toxic metals in atmospheric deposition in Albania. The spatial analysis of each element performed by a space series model, adapted to the time-series linear model, was used to investigate the spatial distribution of the elements. It may visualize the areas characterized by a high concentration level of the toxic elements, particularly of As, Cd, Cr, Hg, Ni and Pb, that are classified as human carcinogens. Multivariate analysis is used to identify the most probable sources of the elements in moss samples. Significant differences were found in the concentrations of As, Cd, Cr, Co, Hg, Ni and Pb in moss samples, and diverse patterns for different elements were found by presenting diverse geographical variabilities in moss metal concentrations. Good correlations were found between the concentration data and the normalized concentration data that indicate higher effects of anthropogenic sources of these elements compared to the natural one. High Ni and Cr contents were found in all territory of Albania. The highest Ni and Cr contents were found in the eastern part that could be classified as highly polluted zone mostly by geological and anthropogenic emission sources. The elements Cr, Ni and Hg exceeded the corresponding median values of European moss. The spatial analysis of the elements (linear model) is possible to identify the areas with a high concentration of certain metals which could suggest for being under control. Wide ranges of metal concentrations were found for As, Hg, Cd, Pb, Ni, Co, Cr and Zn which are characterized by high variations (CV% > 75%). The highest content of Cr, Ni and Co was found in the eastern part of the country. The anthropogenic factors and soil dust associated with the windblown fine mineral dust particles were pointed as another possibility of local emitting factors affecting the accumulation of these metals in mosses. The median value of CR (1.36 × 10−6) is higher than the carcinogenic target risk value (1 × 10−6) and lower than the Cr unacceptable value (CR > 1 × 10−4).KeywordsAtmospheric depositionTrace metalsMoss biomonitoringAir qualityICP-AES analysisHealth riskMultivariate analysisSpatial analysis