Lead smelter studies

A study of 151 children ages 3-6 years old living near a lead smelter in town in Romania found a significant relationship between PbB concentration and NAG activity in the urine (Verberk et al. 1996). The mean PbB concentration among the children was 34.2 pg/dL. NAG activity was found to increase... 

The information available regarding the association of occupational exposure to lead with increased cancer risk is generally limited in its usefulness because the actual compound(s) of lead, the route(s) of exposure, and level(s) of lead to which the workers were exposed were often not reported. Furthermore, potential for exposure to other chemicals including arsenic, cadmium, and antimony occurred, particularly in lead smelters, and smoking was a possible confounder (Cooper 1976 IARC 1987). These studies, therefore, are not sufficient to determine the carcinogenicity of lead in humans, and the following discussion is restricted to the most comprehensive of these studies. 

In a historical cohort mortality study of 1,990 primary lead smelter workers, an SMR of 2.04 for mortality from renal cancer was calculated (Selevan et al. 1985). The cohort consisted of workers who had worked at least 1 year, with at least 1 day of employment at the smelter between 1940 and 1965. The cohort had been heavily exposed to lead and in 1976 the PbB levels averaged 56.3 pg/dL. Exposures to cadmium and arsenic were generally minor. A follow-up study of this cohort was conducted from 1977 through 1988 (Steenland et al. 1992). Analysis of the follow-up study revealed an excess of kidney cancer, particularly in the high-lead group (SMR 2.39). Although, as the authors indicate, the study is... 

Factor-Litvak P, Graziano JH, Kline JK, et al. 1991. A prospective study of birthweight and length of gestation in population surrounding a lead smelter in Kosovo, Yugoslavia. Int J Epidemiol 20 722-728. 

PAH are formed by every high temperature reaction involving organic materials (10). There are a number of industrial processes where PAH can be identified in the workplace atmosphere. Well known examples are coke plants, ferroalloy plants, aluminum plants, secondary lead smelters and others (11,12). In some cases the harmful effect of these compounds has been indicated by epidemiological studies (12). 

Lead sulphide (galena - PbS) is another likely candidate for hydrometallurgical processing particularly in the United States where, apart from the problems of the sulphur dioxide emissions, the lead toxicity problem is making it very difficult for the lead smelters to operate their conventional pyrometallurgical process and comply with EPA and OSHA standards. The total amount of lead mined in the United States is about 600,000 tons per year which, if fully converted, would yield about 100,000 tons per year of by-product sulphur. The Bureau of Mines in Reno, Nevada, have an active pilot plant study to produce lead via a hydrometal-lurigal process (2). In this process the common lead mineral galena is dissolved in an acid brine solution of ferric chloride. 

In a cross sectional study representative sample of randomly selected 31 children with average age of 12.8 years and standard deviation of 0.47 years, from the Veles-polluted area were examined in June 2003. The examinees were living or learning in the vicinity of the Lead Smelter Plant in Veles, Republic of Macedonia. 

A recent study of cancer mortality was performed in a cohort of 4518 lead smelter and battery workers (Wong and Harris 2000). A nested case-control study of stomach cancer was undertaken in this cohort, showing a significant increase of stomach cancer. This finding, however, was not related to the... 

Wong O and Harris F (2000) Cancer mortality study of employees at lead battery plants and lead smelters, 7947-7995. Am J Ind Med 38 255-270. 

Most of these studies have shown that blood lead values are invariably increased by exposure, but little or no health hazard has been adduced. This may be due to the fact that minor effects (e.g. behavioural ones), have not usually been investigated. Lansdowne et al. (1974) linked proximity to a lead smelter in London with increase in blood lead levels. There was however no link between lead and any measure of mental capability that was investigated, and any observed differences that were found could be related to social factors. Hebei et al, (1976) compared distance from a Birmingham battery factory with 11-plus examination scores and found that children who lived near the factory since birth scored more than those with a low lead-load or living in unpolluted areas. They also reported that this difference remained when adjustments were made for social class, birth rank and maternal age. 

Glowiak, B., Zwozdiak, A. Zwozdiak, J. 1979. Studies of atmospheric pollution contributed by air-bome copper and zinc particulates around a copper smelter. Enciron. Protecting Enginiring 5 145-154. Harrison, R.M., Williams, C.R. 1983. Physico-chemical characterization of atmospheric trace metal emissions from a primary zinc-lead smelter. Sci. Total Environ 31 129-140. 

Concentrations of lead in outside dusts vary with their location and inputs. A summary of studies in U.S. EPA (1986, Ch. 7) shows that in rural environments at a time when leaded gasoline was in use, rural roadside dusts were on the order of 80—130 ppm, and urban roadways had dust levels in the range of 1,000—20,000 ppm. Interior household dusts in the United States can present an upper range of 5,600—16,(X)0 depending on source inputs to these dusts such as deteriorating lead paint (Angle and Mclntire, 1979 Clark et al., 1985) or lead smelter emissions (Landrigan et al., 1975). 

Kimbrough, D.E., Suffet, I.H., 1995. Off-site forensic determination of airborne elemental emissions by multi-media analysis a case study of two secondary lead smelters. EnviroiL Sci. Toxicol. 29, 2217-2221. 

Khoury, G.A., Diamond, G.L., 2003. Risks to children from exposure to lead in air during remedial or removal activities at Superfund sites a case study of the RSR lead smelter Superfund site. J. Expo. Anal. Environ. Epidemiol. 13, 51—65. 

Kordas et al. (2004) studied Mexican schoolchildren (N = 602) impacted by a lead smelter in Torreon, Mexico, for associations of PbB elevation (mean= 11.5p.g/dl) and test outcomes on various psychometric tests. The Spanish version of the Peabody Picture Vocabulary Test and the subtests of the WISC-R IQ Test were significantly inversely associated with concurrent PbB measurements. Cho et al. (2010) reported that concurrent PbB in 667... 

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