Levels, Chemical Fractionation, and Solubility of Lead in Roadside Soils of Caracas, Venezuela

Ethnobotanical studies of wild herbs of central Punjab, Pakistan

“…With the support of fertile land and a vast irrigation system majority of the land owners in Central Punjab use pesticides and herbicides to obtain higher yields, which create pollution and destroy vegetation in the adjoining areas. Pollution of gasoline containing heavy metals also causes damage to plants on road verges (Gracia-Miragaya et al, 1981;Gjessing et al, 1984). In all this situation people's awareness about the sustainable use and conservation of these species is primarily essential to control indiscriminate cutting and damaging process before many of these become non-existent.…”

Identification of heavy metal sources by multivariable analysis in a typical Mediterranean city (SE Spain)

“…This characteristic is typical of the traffic as source of these metals (Zhang et al 1990;Madrid et al 2002;Manta et al 2002;Imperato et al 2003). The combustion of tetraethyl and tetramethyl lead in gasoline was the main source which increased the levels of lead in soil (IPCS 1995); their use for cars started since 1923 (Alloway 1995); since the 1980s, there has been a significant reduction in lead pollution due to a decrease in its use as "anti-knock" agent in gasoline; however, due to its persistence in the soil, nowadays this source remains as one of the most important sources of pollution for this metal (García-Miragaya 1984;Albasel and Cottenie 1985;Liu et al 2003;Valerie et al 2004;Kartal et al 2006). In addition, the main roads and highways between the city of Murcia and surrounding cities are included in the areas with highest scores, which support the previous hypothesis.…”

Factors influencing metal bioavailability in soils: preliminary investigations for the development of a critical loads approach for metals

“…Whilst recognising the importance of precipitation in the partition of metals between the solid and solution phases, there are analytical and theoretical problems in extrapolating the concept of solubility products to precipitation reactions in natural soils. Furthermore, it has been shown that the concentrations of elements in the soil solution cannot be explained by solubility isotherms (Brümmer et al, 1983;Garcia-Miragaya, 1984). Natural soil-water systems are known to be much more complex than those in which solubility products are determined, namely solutions in equilibrium with pure compounds.…”

“…Metal solubility tends to increase at lower pH and decrease at higher pH values Alloway, 1995. ) (Tills and Alloway, 1983b;Garcia-Miragaya, 1984;Ram and Verloo, 1985;Sanchez-Camazano et al, 1994;Chuan et al, 1996;Thornton, 1996). This point is also demonstrated in Figure 4 using soils from a catenary sequence of six soils in N.Wales (Rieuwerts et al, 1998b).…”