Urinary excretion of copper and zinc among cigarette smokers

The urinary levels of cadmium (Cd), zinc (Zn) and copper (Cu) were measured among 11 adult male non-smokers and 38 adult male cigarette smokers to investigate the effect of cigarette smoking on the urinary excretion of Zn and Cu in relation to urinary Cd level. The results indicated that among non-smokers, the urinary levels of Cd, Zn, and Cu were: 1.17-5.24 (3.73 +/- 1.23) microg Cd/gm urinary creatinine, 66.73-156.13 (109.28 +/- 30.27) microg Zn/gm urinary creatinine, 83.17-195.65 (126.72 +/- 41.46) microg Cu/gm urinary creatinine, respectively. The cigarette smokers were classified into two groups according to the level of urinary Cd. The first group contains 13 cases with urinary Cd levels within the normal range of non-smokers, and the urinary levels of both Zn and Cu were observed to be also within the normal range of non-smokers (2.14-4.98 (3.85 +/- 0.97) microg Cd/gm urinary creatinine, 69.40-150.59 (97.61 +/- 21.39) microg Zn/gm urinary creatinine, 85.33-137.42 (96.11 +/- 13.60) microg Cu/gm urinary creatinine, respectively]. The second group contains 25 cases with elevated urinary Cd levels (5.44-40.37 (14.08 +/- 9.69 microg Cd/gm urinary creatinine]. The latter group was further subdivided into two subgroups according to the urinary levels of Zn and Cu. The first subgroup contains 15 cases with urinary levels of both Zn and Cu within the normal range of non-smokers [5.44-13.58 (7.74 +/- 2.11) microg Cd/gm urinary creatinine, 69.54-133.46 (96.95 +/- 22.91) microg Zn/gm urinary creatinine, 93.06-191.90 (133.7 +/- 32.80) microg Cu/gm urinary creatinine, respectively]. The second subgroup contains 10 cases with elevated urinary levels of Zn and/or Cu [13.81-40.37 (23.57 +/- 8.74) microg Cd/gm urinary creatinine, 141.53-511.11 (284.76 +/- 132.45) microg Zn/gm urinary creatinine, 193.06-705.48 (388.49 +/- 158.66) microg Cu/gm urinary creatinine, respectively). In the latter subgroup it was noted that only one case showed elevated levels of urinary Cd and Zn but not Cu, while another case showed increased urinary Cd and Cu levels but not Zn. The results of the present investigation suggest that urinary Cd, at a certain level, may be accompanied by increased urinary excretion of both Zn and Cu among cigarette smokers.