Copper contamination from domestic tap water with a descaler

Sir -- Drinking-water is potentially a major source of copper exposure because of the widespread use of copper pipes in household plumbing. We describe a patient who complained of abdominal pain and green hair. Examination revealed high levels of copper in the blood, urine and hair, which we were able to link to the installation of a household descaling device. A 32-year-old woman, with no history of substance abuse, who was not taking any regular medication and whose medical history was unexceptional except for sporadic self-limiting episodes of abdominal pain, requested medical advice for a patchy, non-homogenous green discoloration of the hair, especially of the temporal and occipital areas, that had begun two months earlier. Physical examination was normal; the natural hair colour was blonde. The analytical results included the following: copper in serum: 41 [micro]mol/l (normal range (NR): 11-23[micro]mol/l); copper in urine: 0.78 [micro]mol/24h (NR: [is less than] 0.6 [micro]mol/l); ceruloplasmin: 30 mg/dl (NR: 25-40 mg/dl); and copper in hair: 1392 [micro]g/g (NR: 41.7 [+ or -] 4-21.2 [micro]g/g). Microscopic examination of the hair showed some minor alterations of the cuticular layer of the shaft. The appearance of green hair coincided with a change of domicile. The patient had moved to a dwelling where all the water pipes were made of copper, and a descaler using a method of exchange resins had been incorporated into the household water system. Analysis of the water (pH, 7.2-7.4) from the kitchen and bathroom taps showed the following cation concentrations: copper, 1.2-1.95 mg/l; calcium, 5.8-8.6 mg/l; and magnesium, 3-4 mg/l. The copper concentrations were generally higher in water from the hot-water pipes than from the cold-water pipes. The mains water entering the house had the following cation concentrations: copper, 0.02 mg/l; calcium, 171 mg/l; and magnesium, 58 mg/l. The patient was treated only with shampoo containing D-penicillamine, the & scaler was disconnected, and the patient's hair recovered its original colour within two weeks. Three months after disconnection of the descaler, significant changes were found in the cationic concentrations of the household tap water: copper, 0.5-0.9 mg/l; calcium, 140-160 mg/l; and magnesium, 47-50 mg/l. Over the same period, the concentrations of copper in the blood and urine of the patient fell to 29 [micro]mol/l and 0.27 [micro]mol/l, respectively. Effects observed in humans following the consumption of water contaminated with copper have been gastrointestinal (vomiting, diarrhoea, nausea, abdominal pain and a metallic taste in the mouth), hepatic (micronodular cirrhosis) and renal (necrosis of tubular cells) (1, 2), and an exogenous pigmentation (green hair) from increased copper in domestic tap water or swimming pool water (3). …