Heavy Metals Accumulation In Roadside Soil And Vegetation Along A Major Highway In Libya

Abstract

Levels of some heavy metals in soil and vegetation along a major highway in Libya were determined by Atomic Absorption Spectrophotometry. The concentrations of Pb, Cd, Ni, Zn, Cu, Cr and Mn in soil and vegetation all decreased with distance from the road, indicating their relation to traffic. The concentrations of the metals also decreased with depth in the soil profile indicating that the source of the metals was aerial deposition from motor vehicles. Inter-relationships between metals in the soil were highly significant (p < 0.05) suggesting a common source for these metals. Pb and Zn were found to be deposited more than the other metals. Average values for citrus limon leaves were generally 30 -65 % of those for Olea europaea leaves. In most cases, between 20-40% of the metals was removable by simple washing with water, indicating that a significant, but not predominant fraction of the metals is in the form of easily-removed particulate matter. Discussion of the results of this study is based on statistical treatment of the data.

Heavy metals concentration in teak (<i>Tectona grandis</i> Linn. F.) and topsoil at roadside in University of Benin, Benin City, Nigeria

“…This research outcomes in which the concentrations of all the detected heavy metals in samples of topsoil close to the road were higher than those for topsoil at increasing distance from the road appeared to be in line with those for some similar studies, such as Voegborlo and Chirgawi (2007); Bai et al, (2008), Nakayama et al, (2011) and Aslam et al, (2013), where similar observations of this kind, concerning heavy metals, were linked to levels of traffic density and distance of topsoil from roads regularly used by motorised vehicles powered by petroleum fuels. The main medium through which these pollutants are released from these vehicles, according to studies, is their exhaust gases after the combustion of the different types of fuels by the different vehicles.…”

“…These heavy metals, particularly lead, have been reported in publications to be almost always present in topsoil and tissues of plants polluted by exhaust from automobiles after fuel combustion in vehicular engines (Gratani et al, 1992;Bahemuka and Mubofu, 1999;Renberg et al, 2000;Yaman et al, 2000;Andrews and Sutherland, 2004;Finster et al, 2004;Yakupoglu et al, 2008;Ikenaka et al, 2010;Aslam et al, 2013). Certain chemical compounds, known to contain lead, were added to gasoline in the past and currently in parts of the world as anti-knocking agent (Wheeler and Rolfe, 1979;Hafen and Brinkmann, 1996;Turer and Maynard, 2003;Iqbal and Shazia, 2004) although, efforts are increasing towards ensuring the reduction in the maximum permitted quantity of lead in fuels (Voegborlo and Chirgawi, 2007). For instance, it was reported that lead content in gasoline was markedly decreased in the United Kingdom after the introduction of the regulations requiring the reduction in the lead content from 0.64 g/l in 1966 to 0.14 g/l in 1986.…”

Heavy Metals Accumulation in Soil and Mango Leaf and Their Effects on Soil Microbial Population along Road Sides in Southwest, Nigeria

“…The change in the metal concentrations with distance from the edge of the road was not consistent as reported by different authors. These results agreed with that of Voegborlo [19] who reported clearly defined gradients of lead contamination beside roadways, and less-defined gradients of other metals including cadmium, chromium, copper, nickel, vanadium, and zinc. Variations in the concentration of heavy metals in soil profiles are normally not consistent and readily interpreted because a number of factors can influence the level of metals in a soil profile and these include nature of parent material, the organic matter content environmental factors and chemical properties of the soil as well as the metal solubility.…”

The Effect of Industrial Heavy Metal Pollution on Microbial Abundance and Diversity in Soils — A Review

“…Moreover, grease used in vehicles may also be the source of cadmium pollution along roads [44]. Nickel emission results from this metal being added in gasoline and atmospheric abrasion of nickel-containing parts of automobiles [45]. The changes in the concentrations of lead, nickel, cadmium, copper and zinc in roadside soils are frequently attributed to traffic density [46].…”