Copper is a widely available metal that is associated with both acute and chronic poisoning. Although essential to life, acute overdose with copper salts produces severe gastrointestinal (GI) and systemic effects that may be life threatening. This clinical syndrome and the underlying mechanism is similar to that noted with iron poisoning. Regardless of the means of exposure, patients with acute copper poisoning require expeditious identification and empiric therapy.
Copper is available naturally, either as native copper (elemental copper) or as one of its sulfide or oxide ores. Important ores include malachite (CuCO3·(OH)2), chalcocite (Cu2S), cuprite (Cu2O), and chalcopyrite (CuFeS2 or Cu2S·Fe2S3). Chalcopyrite, a yellow sulfide ore, is the source of 80% of the world's copper production. The smelting, or separation, of copper ores began about 7000 years ago; copper gradually assumed its current level of importance at the start of the Bronze Age, around 3000 B.C. Smelting begins with roasting to dry the ore concentrate, which, in more modern times, is further purified by electrolysis to a 99.5% level of purity. The sulfide ores have a naturally high arsenic content, which is released during the extraction process, posing a risk to those who perform copper smelting.
Although acute copper poisoning is uncommon in the United States, the historical role of copper as a therapeutic agent remains noteworthy. Copper sulfate was used in burn wound debridement until cases of systemic copper poisoning were reported.63 Interestingly, in one report, each wound debridement procedure was associated with an 8% to 10% decrease in the hematocrit. In the 1960s, copper sulfate (250-mg dose containing 100 mg copper ion) ironically was recommended as an emetic agent, typically for use in children after potentially toxic exposures.70 It was recognized for its rapidity of onset and effectiveness, and it compared favorably with syrup of ipecac. However, copper-induced emesis was rapidly identified to be a highly dangerous practice, and this use was generally discontinued,64,78,118 although fatal cases from this use still occur.78 Copper salts are administered in religious rituals as a green-colored "spiritual water" containing 100 to 150 g/L of copper sulfate as an emetic to "expel one's sins."7,117
A growing body of knowledge links copper to the promotion of both physiologic and malignant angiogenesis.59 In this latter case, copper may enable tumor expansion, invasion, and metastasis. Additionally, copper binding to amyloid fibers in the brain of patients with Alzheimer's disease may lead to local oxidative damage and cause the characteristic neurodegeneration.25,39 Copper is also similarly implicated in the pathogenesis of both Parkinson's disease and autism.28,131
Acute or chronic copper poisoning may occur when the metal is leached from copper pipes or copper containers. This occurs frequently when carbon dioxide gas, used for postmix soft drink carbonation, backflows into the tubing transporting ...