BIOLOGICAL MONITORING OF EXPOSURE TO CADMIUM, A HUMAN CARCINOGEN, AS A RESULT OF ACTIVE AND PASSIVE SMOKING

Cadmium (Cd), a known human carcinogen is one of the components of tob acco and also has many industrial uses. Smoking Cd-contaminated cigare ttes at work may cause an increase in blood levels and toxicity of Cd. For a population of nonexposed workers, we compared blood Cd and urin e cotinine (Cot) levels as biological markers of exposure to cigarette smoke of active smokers (AS) and passive smokers (PS) with those of u nexposed nonsmokers (UNS) in 158 workers. The mean Cd in AS (0.097 mu g%; ie, 0.097 mu g/100 mt whole blood) tons significantly higher. than in UNS (0.085 mu g%), and was very close to the mean Cd levels in PS (0.093 mu g%). Mean Cd levels in exposed past smokers (0.105 mu g%) wa s higher than in nonexposed past smokers (P < 0.05) and in AS. The mea n Cot level was significantly higher in AS than in PS or in UNS. Incre ased smoking was associated directly with increased blood Cd and urine Cot. Our results supported and proved quantitatively that exposure to cigarette smoke is harmful to both AS and PS, as we show that in both cases there is an increase in blood Cd. According to our results, exp osure to cigarette smoke via active and background (UNS). We conclude that exposure to cigarette smoke is a confounder to be taken into acco unt when carrying out epidemiological studies and surveillance program s on workers exposed to Cd at work.