Mercury and Lead Toxicity
MERCURY TOXICITY
dental amalgam source
pts with ideopathic dilated cardiomyopathy had 200,000 more mercury than controls
Minamata-Hg compounds dumped into bay--people in town began to develop strange symptoms, numbness in lipms and lips, difficulting seeing or hearing, shaking (tremors) in arms and legs, difficulty walking, brain damage.
http://en.wikipedia.org/wiki/Minamata
http://en.wikipedia.org/wiki/Minamata_disease
Children were born in town with severe deformities, gnarled limbs, mental retardation, deafness and blindness
LEAD TOXICITY
lead absorption causes Zn, Ca, Fe def
children absorb 4-5x more lead
for adulst inhalation primary source, for kids ingestion
lead storage: 85% bones, 10-15% teeht
predominantly excreted by kidneys
lead binds sulfhydryl groups, denatures proteins, affects calcium metabolism, affects membrane pumps (Na/K), affects CNS/PNS, decreases active vitamin D production
clinical effects:
hypochromic microcytic anemia with basophillip stilling
incr zinc protoporphyrin and free erythrocyte protoporphyrin because Pb inhibits Fe being placed in heme molecule: no ferrochetalase
CNA in kids: decr IG, learning disabilities, delayed motor and emotional development
PNS in adults, can be misdiagnosed as MS
lead "colic" pulling sensation on umbilicus
lead line on gums
lead line at empiphysis in children
sources of lead
pica: food, dust, crayons
water
parental occupation
kids absorb more lead when exposed and more likely to get cns sx
BBB more permeable first 3 yrs of life
for adults: mining, batteries, ammo, pipes, cans, gasoline, shooting galleries, homemade whiskey, leaded crystals, hair dye, contaminated mineral supplements
SOURCE
SSL's pathology 1 notes, 2010