Smelter area studies

Smelter area studies Landrigan et al Smelter area... 

The above smelter area studies, particularly the more recent, better... 

Figure 4 shows an isomap of the lead pollution in the first smelter area of the Dallas Lead Study. The round symbol in the center represents the smelter. The lines are isopleths of lead in soil in pg/g. Note the cluster of closed isopleths encircling the smelter. The large number of concentric isopleths encircling the smelter shows a steep gradient or rapid change in a short distance between a low (200 ig/g) outside and a high (3,000 pg/g) inside. 

Very enhanced concentrations of some elements, especially Pb, Cd, Zn, Sn, Sb, As were found in the feather samples from the vicinities of all the studied zinc smelter areas (Znl, Zn2, Zn3) (Figs. 2 and 3). Some of them were at least a dozen and sometimes scores of times higher than, e.g. those in the samples from the surroundings of the Pel or Fe2 steelworks, and lignite-fired power plants ppl or pp2, so far considered... 

Table I indicates the sample size and population estimates of preschoolers by study area and stratum. Though all strata for the Dixie site are shown, at the Dixie site the configuration and location of the major traffic artery in relation to the smelter site did not allow analysis of the contribution of vehicular traffic to soil lead. The contribution of the smelter to soil lead levels was possible at the RSR site and the reference site.

Implications for Source Studies. The results discussed above Indicate the need for measurements of a number of elements In studies of particles both from sources and In ambient air. Measurements of Na, Pb, Ca, As, Mn and V are very Important for use In receptor models. Aluminum and Fe are quite useful, but not essential If many other llthophlle elements are measured (e.g., SI, Tl, Sc). Likewise, Zn Is useful, but could be replaced by elements such as Sb and Cd. However, AI, Fe and Zn can usually be measured more easily than their surrogates. Iron and elements such as Cr, Mn, Co and N1 will be Important In areas that have Iron and steel Industries and elements such as Cu, Zn, Pb and other chalcophlles In areas that have non-ferrous metal Industries. Sources of the unexplained Mn, Cr, Cu, Nl, K and Mg In Washington need to be Identified. Thus, we have a set of about 15 elements that should be measured as a minimum, plus others that may provide additional useful Information, e.g., Br, Ba, Cd, Sb. Note that It Is not sufficient to measure a given element only In particles from the dominant source of the element. For example, motor vehicles are the major source of Pb In most areas however, significant amounts are released by refuse Incinerators and non-ferrous smelters. Thus, If the CEB Is to determine the correct source strength for the motor—vehicle component, Pb contributions from the other, less Important sources must be known. 

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