Lead Damage

As mentioned, extraction techniques and related tools are mainly designed for leads in normal condition. Any damage to the lead, due to its characteristics or failure (subclavian crush, loss of insulation, wire protrusion) or to previous ineffective attempts at removal, may heavily impact the transvenous removal procedure, often requiring unconventional approaches. In the following paragraphs the most common situations are addressed. 

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Piomelli S, Seaman C, Zullow D, et al. 1982. Threshold for lead damage to heme synthesis in urban children. Proc Natl Acad Sci. 7 3335-3339. 

S.Piomelli, C.Seaman, D. Zulow, A.Curran, and B.Davidow (1982), The threshold for lead damage to hemo synthesis in urban children, Proc. Nat. Acad. Sci., 79, 335. 

These radioactive isotopes are solids that can collect on dust. When the dust is inhaled, the radioactive solids remain in the lungs. High-energy alpha particles from the polonium and lead damage the DNA of lung cells, sometimes causing cancer. 

Removing all pollutants from water would be difficult and expensive, but concentrations below the MCE and MCLG are considered harmless. Lead damages kidneys, and chronic exposure to even tiny amotmts may cause damage to the nervous system. The MCLG of lead is 0 the EPA maintains that no amount of lead should be consumed for an extended time. The MCL of lead is 0.015 ppm, but consumption of even low levels of lead in water is not recommended. Both the MCLG and MCL of mercury are set at 0.002 ppm. 

CHRONIC HEALTH RISKS fetal damage may occur from exposure of the mother to tetramethyl lead damage to kidneys may cause effects on cardiovascular system and central nervous system. 

The mechanisms by which lead damages the developing brain probably involve multiple molecular, biochemical and cellular processes, including neurotransmitter release, second messenger signaling pathways, immediate-early and delayed gene expression, and neural network plasticity (Minnema et al 1986 Dressier et al 1999 Kim et al., 2000 Wilson et al 2000). 

Lead damaged by previous unsuccessful removal attempts After an unsuccessful transvenous lead extraction (TLE), leads could be seriously damaged. Coil or insulation fracture irreversibly modifies the lead body structure, reducing the procedural success and increasing procedure complexity and complications. Intravascular leads When no part of the lead can be approached outside the vascular system, a crossover to the transfemoral or transjugular approach is mandatory. 

Lead damage Coil is lengthened or any stylet cannot be inserted Dilating sheath with high-encjgy dilatation may induce venous tears or complete lead fracture Transjugular approach... 

Other health effects (total number of people affected) Lead damage to children (CDC 1994)... 

OTlaherty, E.J., Hammond, P.B. and Lemer, S.I. (1982) Dependence of apparent blood lead half-life on the length of previous lead exposure in humans. Fund. Appl. Toxicol, 2, 49-54 Pinchin, M.J., Newham, ]. and Thompson, R.P.J. (1978) Lead, copper and cadmium in teeth of normal and mentally retarded children. Clin. Chim. Acta, 85, 89-94 Piomelli, S., Seaman, C., Zullon, D., Currin, A. and Davidow, B. (1982) Threshold for lead damage to heme synthesis in urban children. Proc. Natl. Acad. Sci. USA, 79, 3335-3339 Piomelli, S., Rosen, J.F., Chisolm, J.J., Jr and Graef, J.W. (1984) Management of childhood lead poisoning. ]. Pediat., 105, 523-532... 

FIG. 30 Component placement, a) A BGA component being placed onto its corresponding PCB attachment pads, b) Peripheral-leaded devices (SOICs and QFP) being inspected by an upward looking camera prior to placement. The camera inspects the components for both feature location and lead damage. (Courtesy of Universal Instruments Corporation). 

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