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Unformatted text preview: Lecture 13 10/18/11 Case Studies in Metals • WILL BE ON EXAM! • Exam – same format, same length Metals • graph of quality of health (y-axis: bad health = bottom, good health = top) vs. dose of metal (x- axis) • Essential Metals- our bodies need these to work properly ◦ copper ◦ iron- use to carry hemoglobin ◦ manganese ◦ dose curve: too little or too much- BAD for your health. Optimum level in the center. • Nonessential metals- no useful functions in our bodies ◦ mercury ◦ cadmium ◦ as you increase dose, quality of health decreases - generally TOXIC Factors that Affect Metal Toxicity • level and duration of exposure • chemical form of metal – affects toxicokinetics • metal-protein complexes ◦ metals attack proteins (proteins are the targets!) • host factors ◦ lifestyle ◦ gender ◦ age-poverty ◦ immune status Endogenous Protection Against Metal Toxicity • metallothionein – PROTECTOR (thio refers to SULFUR – this is a protective protein in your body. If non-essential metals get too high, this protein will go after them, bind them, and protect you) ◦ high cysteine content (30%) ◦ high metal content (8-12 atoms/molecule) ◦ low molecular weight ◦ inducible at level of gene expression metals (Cd, Hg, Cu, Zn) ▪ you can increase its level to protect you ▪ but have to be careful to not get too much of it or else it will bind essential metals too! ◦ Function: ▪ metal detoxification ▪ metal homeostasis (metal metabolism) • Chelation Methods of Therapy for Metal Toxicity ◦ you can chelate metal to help excrete them too ◦ problem with chelators – they also bind essential metals ◦ chelators are given to children to bring down their lead levels Toxic Metals and the Legacies of Mining • Leadville, Colorado: The closing of the Climax mine in the 1980s was a major blow to the town's economy. In addition, the many years of mining left behind … ◦ Lead tailings (piles and piles of lead) ◦ Children had high blood lead levels – low IQs ◦ Leadville TOWN was designated a Superfund site ◦ Town is now 98% cleaned up and Superfund designation is about to expire ◦ The town has made major efforts to improve its economy by encouraging tourism • Sierra Nevada- Gold Mining ◦ remove gold from dirt by using mercury ◦ thus there is a legacy in the Sierras about Mercury poisoning ◦ high incidence of breast cancer in that region • Gypsy families in North Mitovica, Kosovo: the Roma children ◦ 100 million tons slag heap of lead, zinc, and arsenic from the Trepeca smelter ◦ This disaster in Kosovo referred to as the most major environmental disaster in Europe! ◦ These children have so much lead in them, they have depressed IQs, rotten teeth, etc....
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- Fall '11
- Lead poisoning, Mercury poisoning, blood lead levels, Daily Mercury Exposure