Copper contamination from domestic tap water with a descaler
Santiago NoguéI; Pere SanzI; Pere MunnéI; Enrique GadeaII
IToxicology Unit, Hospital Clínic i Provincial de Barcelona, Department of Public Health, University of Barcelona, Spain
IIInstituto Nacional de Seguridad e Higiene en el Trabajo, Barcelona, Spain
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 mmol/l (normal range (NR): 1123 mmol/l); copper in urine: 0.78 mmol/24h (NR: <0.6 mmol/l); ceruloplasmin: 30 mg/dl (NR: 2540 mg/dl); and copper in hair: 1392 mg/g (NR: 41.7 + 21.2 mg/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, 7.27.4) from the kitchen and bathroom taps showed the following cation concentrations: copper, 1.21.95 mg/l; calcium, 5.88.6 mg/l; and magnesium, 34 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 descaler was disconnected, and the patients 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, 0.50.9 mg/l; calcium, 140160 mg/l; and magnesium, 4750 mg/l. Over the same period, the concentrations of copper in the blood and urine of the patient fell to 29 mmol/l and 0.27 mmol/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). For the case we have reported on here, the increased copper content was produced by a descaler which drastically reduced the concentrations of calcium and magnesium in the water, thereby converting the water into a corrosive agent which dissolved the copper in the pipes.
Although the concentrations of copper found in the domestic water supply were within those accepted by the Environmental Protection Agency (EPA) (1.3 mg/l) and WHO for drinking-water (2 mg/l, provisional) (47), the patient suffered abdominal pains, had green hair, and high concentrations of copper in her blood, urine, and hair. This would seem to indicate the need to revise the legislation regulating permissible copper concentrations in mains water supplies, as already proposed by Sidhu et al. (8), with a view to establishing the maximum permissible concentration of copper at 0.3 mg/l, given that various reports have been published describing chronic copper intoxications due to the ingestion of mains water containing copper concentrations within the limits accepted by both EPA and WHO.
1. Spitalny KC et al. Drinking-water-induced copper intoxication in a Vermont family. Pediatrics, 1984, 74: 11031106.
2. Müller-Höcker J et al. Different pathomorphologic patterns in exogenic infantile copper intoxication of the liver. Pathology, Research and Practice, 1998, 194: 377384.
3. Blanc D et al. [Green hair: a clinical, chemical and epidemiological study]. Annales de Dermatologie et de Vénéréologie, 1988, 115: 807812 (in French).
4. Fitzgerald DJ. Safety guidelines for copper in water. American Journal of Clinical Nutrition, 1998, 67 (suppl.): 1098S 1102S.
5. Guidelines for drinking-water quality. Vol.1: Recommendations, 2nd ed. Geneva, World Health Organization, 1993.
6. Guidelines for drinking-water quality. Vol.2: Health criteria and other supporting information, 2nd ed. Geneva, World Health Organization, 1996.
7. Guidelines for drinking-water quality. Vol.3: Surveillance and control of community water supplies, 2nd ed. Geneva, World Health Organization, 1997.
8. Sidhu KS, Nash DF, McBride DE. Need to revise the national drinking-water regulation for copper. Regulatory Toxicology and Pharmacology, 1995, 22: 95100.
Instituto Nacional de Seguridad e Higiene en el Trabajo
Dr Pere Sanz, Ronda General Mitre 39
08017 Barcelona, Spain