Community-based randomized double-blind study of gastrointestinal effects and copper exposure in drinking water.
We assessed gastrointestinal effects in 1,365 adults exposed to either < 0.01 (controls), 2, 4, or 6 mg copper/L of drinking water for 2 months in a randomized, double-blind community-based study. The risk of symptoms increased with increasing Cu exposure and decreased with time. The best model by counting-process analysis included Cu concentration and sex. The risk of symptoms remained significantly higher in women than in men during weeks 1-4 for all concentrations tested; at week 1 comparison with the < 0.01-mg/L group showed that differences became significant in women at 4 mg/L [relative risk (RR) = 1.53; 95% confidence interval (CI), 1.02-2.05), and in men at 6 mg/L (RR = 1.9; 95% CI, 1.02-2.79). At week 2 for men and week 4 in women, the Cu concentration required to obtain significant differences on symptom report was > 6 mg Cu/L. We conclude that exposure to Cu in drinking water results in gastrointestinal symptoms, which are modulated by Cu concentration, time, and sex.
Araya
Magdalena
M
Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile. maraya@uec.inta.uchile.cl
Olivares
Manuel
M
Pizarro
Fernando
F
Llanos
Adolfo
A
Figueroa
Guillermo
G
Uauy
Ricardo
R
D000328:Adult; D003300:Copper / Q000506:poisoning*; D004311:Double-Blind Method; D005260:Female; D005767:Gastrointestinal Diseases / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology; D018570:Risk Assessment; D012737:Sex Factors; D014881:Water Supply
D003300:Copper