Determination of cadmium in whole blood and scalp hair samples of Pakistani male lung cancer patients by electrothermal atomic absorption spectrometer.

A large number of epidemiologic studies have been undertaken to identify potential risk factors for cancer, amongst which the association with cadmium has received considerable attention. There is compelling evidence in support of positive associations between cadmium and risk of lung cancer. In present study we measured the concentration of Cd in whole blood and scalp hair samples of 120 male lung cancer patients (smokers) and 150 controls or referents (smokers and nonsmokers) from different cities of Pakistan. Both referents and patients were of same age group (ranged 40-70 years), socio-economic status, localities and dietary habits. The scalp hair and whole blood samples were oxidized by 65% nitric acid: 30% hydrogen peroxide (2:1) ratio in microwave oven. To check the validity of the proposed method, a conventional wet acid digestion method was used to obtain total Cd concentration in certified samples of human hair BCR 397 and Clincheck control-lyophilized human whole blood. All digests were analyzed for Cd concentration by electrothermal atomic absorption spectrometer (ETAAS). The results of this study showed that the average Cd concentration was higher in the blood and scalp hair of lung cancer patients at different stages as compared to controls (p<001). The smoker referents have high level of Cd in both biological samples as compared to nonsmoker subjects. These results illustrate that the patients who continued smoking after confirmed diagnosis of lung cancer have 34.2-67.26 and 22.4-57.3% more Cd in blood samples and scalp hair than lung cancer patients who cease smoking. This study is compelling evidence in support of positive associations between cadmium, cigarette smoking and lung cancer risk.