Effects of Lead Poisoning

Virtually no part of the body is immune from the effects of lead. Lead in the body dismpts energy metabolism at the cellular level, interferes with neural cell function in the brain, disrupts the formation of heme and in the nervous system, inhibits communication and decreases nerve conduction velocity. Even at relatively low exposures, lead s neurotoxic effects can cause decreased intelligence, short-term memory loss, reading under-achievement, impairment of visual-motor function, loss of auditory memory, poor percepmal integration, poor classroom behavior, and impaired reaction time. 

The mechanism by which lead affects the human body is extremely complex, as demonstrated by Landrigan and Needleman (1991) in Civil Action No. 87-2799-T, U.S. District Court for the District of Massachusetts in 1991. On an atomic level, lead has no biologic value and competes with metals that are essential to the human body, such as zinc, iron, and calcium. When lead inserts itself into the binding site of proteins, such as enzymes, in place of these essential metals, it distorts the biomolecules and their functions. For example, in certain membrane channels, lead occupies calcium s place, thereby blocking the flow of calcium within cells or across cell membranes. Since calcium is a very important regulator, this lead-calcium interaction affects memory storage and cell differentiation in the nervous system. 

Lead inhibits certain neuronal pathways in the brain and disinhibits others. As a result, the system is less able to store information, draw on past information or memory, or inhibit responses to environmental stimuli. Lead effects the peripheral nervous system, the nerves that control the muscles and organs of the body outside the brain, by stripping off the coating, known as myelin, that ensheathes the system. This disrupts the propagation of electrical 

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Occupational disease is not a new phenomenon. Ample historical evidence exists recounting the effects of lead poisoning, chronic respiratory problems associated with mining, and hazards of manufacturing (including traumatic injury)-... 

Hu-Howard. Knowledge of Diagnosis and Reproductive History among Survivors of Childhood Plumbism. American Journal of Public Health. 81 (Aug. 1991) 1070-1072. Source for third-generation effects of lead poisoning. 

Rummo JH. 1974. Intellectual and behavioral effects of lead poisoning in children. Chapel Hill, NC University of North Carolina. University Microfilms, Ann Arbor MI, Publication No. 74-26-930. 

The child pictured in Figure 1.1 working in a lead battery recycling factory in Bangladesh illustrates the global implications of toxicology. This child will suffer from the effects of lead poisoning for a lifetime and will not be able to reach his intellectual potential. 

All the surface processes on automotive catalysts which have been tested for the effects of lead poisoning are affected by the access of lead to the catalyst surface. The effect will differ, though, for different surface processes. Oxidation of hydrocarbons has been found repeatedly to be more vulnerable than oxidation of carbon monoxide to lead poisoning (10, 19, 25). The initial oxidation activity of noble metal catalysts, never exposed to poisons, is higher for CO than for hydrocarbons (54). Therefore, it is best to use the effect of lead on hydrocarbon oxidation for assessing the susceptibility of a given oxidation catalyst to this type of poisoning. 

Lead is widely destributed in the environment, especially in industrial and urban areas, and it is readily absorbed into the mammalian body where it exerts a number of undesirable physiological effects. Its most dramatic action is the inhibition of human red cell 5-aminolaevulinic acid dehydrase activity71), but it also depresses the activities of many enzymes having functionsl -SH groups. Attempts to remove lead from the body using agents such as dimercaptopropanol can result in the formation of lipid-soluble lead complexes that may be carried to the brain and exacerbate the effects of lead poisoning. 

Karp inski FE, Rieders F, Girsh LS Calcium disodium versenate in the therapy of lead encephalopathy. J Pediatr 42 687-699, 1953 Kirkconnell SC, Hicks LE Residual effects of lead poisoning on Denver Developmental Screening Test scores. J Abnorm Child Psychol 8 257-267, 1980 Kotok D Development of children with elevated blood lead levels a controlled study. J Pediatr 80 57-61, 1972... 

Thurston DL, Middelkamp JN, Mason E The late effects of lead poisoning. J Pediatr 47 413-423, 1955... 

Certain factors are analyzed to determine their effects on automotive catalyst activity. At operating gas velocities, spherical catalysts were more active than monolithic catalysts at comparable catalyst volumes and metals loadings. Palladium was the most active catalyst metal. Platinum in a mixed platinum palladium catalyst stabilizes against the effects of lead poisoning. An optimum activity particulate catalyst would contain about 0.05 wt % total metals on a gamma-alumina base with a platinum content of 0.03-0.04 wt % and a palladium content of 0.01-0.02 wt %. A somewhat thick shell of metals located near the outer surface of the particle provides better catalyst activity than a shell type distribution of metals. 

To determine which of the effects of lead poisoning are reversible and which are permanent. 

Agbo, S. (1997). Effects of lead poisoning in children. In Proceeding at a workshop on vehicular emission and lead poisoning in Nigeria. Friends of the environment, pp 20-28. 

Tenconi LT, Acocella G (1966) Study on the Chemotherapy of Experimental Lead Poisoning. 1. Effects of Lead Poisoning on the Tryptophan to Nicotinic Acid Metabolism in the Rat. Acta Vitaminologica 20 189... 

Kotok, D., Kotok, R. and Heriot, J. T. (1977). Cognitive evaluation of children with elevated blood lead levels. Am. J. Dis. Child., 131, 791 Krall, A. R., Pesavento, C., Harmon, S. J. and Packer III, R. M. (1972). Elevation of norepinephrine levels and inhibition of mitochondrial oxidative phosphorylation in cerebellum of lead-intoxicated suckling rats. Fed. Proc., 31,665 (abstract 2537) Krall, V., Sachs, H., Rayson, B., Lazar, B., Growe, G. and O Connell, L. (1980). Effects of lead poisoning on cognitive test performance. Perceptual Motor Skills, 50, 483... 

This document outlines the medical monitoring program as defined by the occupational safety and health standard for inorganic lead. It reviews the adverse health effects of lead poisoning and describes the important elements of the history and physical examinations as they relate to these adverse effects. Finally, the appropriate laboratory testing for evaluating lead exposure and toxicity is presented. 

Byers RK, Lord EE (1943) Late effects of lead poisoning in mental development. Am. 

Children are more susceptible to the effects of lead poisoning than adults. Lead is more dangerous to children because ... 

Byers, R.K., Lord, EJi., 1943. Late effects of lead poisoning on mental development. Am. J. Dis. Child. 66, 471-494. 

As with the vascular pathology, the most pronounced neuronal and glial effects of lead poisoning ai e seen in the cerebellum. Cerebellar weight and total cell number ai e reduced" and the size and morphology of Purkinje cell bodies cire abnormal."" " The intemeuron circuitry of the cerebellum is also altered, since the dendritic development of the Purkinje cells, which form the only efferent elements of the cerebellar cortex, is markedly disturbed by lead exposure. Press observed a decrease in the rate of Purkinje cell maturation in lead-poisoned rat pups from about 5 d onwards such that, at 10 d, the leaded cells retained more perisomatic processes than controls and the den-... 

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