The use of
zinc in
metal alloys and medicinal lotions dates back before the time of Christ. Currently, most of the commercial production of
zinc involves the galvanizing of
iron and the manufacture of
brass. Some studies support the use of
zinc gluconate lozenges to treat the
common cold, but there are insufficient data at this time to recommend the routine use of these lozenges.
Zinc is an essential co-factor in a variety of cellular processes including
DNA synthesis, behavioral responses, reproduction, bone formation, growth, and wound healing.
Zinc is a relatively common
metal with an average concentration of 50 mg/kg soil and a range of 10-300 mg/kg soil. Meat, seafood, dairy products, nuts, legumes, and whole grains contain relatively high concentrations of
zinc. The mobility of
zinc in anaerobic environments is poor and therefore severe
zinc contamination occurs primarily near points sources of
zinc release. The recommended daily allowance for adults is 15 mg
zinc. The ingestion of 1-2 g
zinc sulfate produces
emesis.
Zinc compounds can produce irritation and corrosion of the gastrointestinal tract, along with acute renal tubular
necrosis and
interstitial nephritis. Inhalation of high concentrations of
zinc chloride from
smoke bombs detonated in closed spaces may cause chemical
pneumonitis and
adult respiratory distress syndrome. In the occupational setting inhalation of fumes from
zinc oxide is the most common cause of
metal fume
fever (
fatigue,
chills,
fever, myalgias,
cough,
dyspnea,
leukocytosis, thirst,
metallic taste, salivation).
Zinc compounds are not suspected
carcinogens. Treatment of
zinc toxicity is supportive.
Calcium disodium ethylenediaminetetraacetate (CaNa2EDTA) is the
chelator of choice based on case reports that demonstrate normalization of
zinc concentrations, but there are few clinical data to confirm the efficacy of this agent.