Cadmium accumulation in the lung, liver and kidney of mice and rats chronically exposed to cigarette smoke.

Cigarette smoking constitutes a major source of cadmium exposure via inhalation in man. To determine how smoke exposure affects the organ distribution and accumulation of cadmium, male C57B1 mice and Sprague-Dawley rats were exposed daily for 52-60 consecutive weeks to mainstream smoke from the University of Kentucky reference cigarettes (2R1) in a nose-only exposure system. Exposed mice and rats averaged blood carboxyhemoglobin values of 17.7 and 7.2%, and a daily total particulate matter (TPM) dose of 7.2 and 3.2 mg kg-1 body wt. per exposure, respectively. These results suggested effective inhalation of smoke by the animals. The tissues were acid digested and analyzed for cadmium by atomic absorption spectrometry. Cadmium levels 5-6- and 2-3-fold greater than control levels were detected in the lungs and kidneys, respectively, of exposed animals of both species. In contrast, the liver did not show increased cadmium levels in exposed mice or rats. The data suggest that low-dose chronic inhalation exposure to cigarette smoke leads to highest cadmium accumulation in the lung, followed by the kidney, with minimal effects on cadmium levels in the liver.