Chemical carcinogens are generally activated enzymatically to electrophiles that form covalently bound carcinogen-DNA adducts. Detoxifying enzymes are competing with the activating enzymes for these procarcinogenic chemical substrates. Wide person-to-person variations in these two types of enzymatic activities are found. Repair rates of DNA damage caused by carcinogens also vary among individua...

depends upon: (a) concentration of caffeine; (fc) time of addition of caffeine; (c) length of exposure; and (d) carcinogen used. The addition of caffeine to cells treated 1 hr previously with carcinogen resulted in the potentiation of toxicity. Toxicity increased with caffeine concentration and length of exposure to carcinogen-containing medium. With 50 ¿ig caffeine per ml medium for 2 days cl...

An approach is presented to the assessment of carcinogen risks in which the dominant effect of carcinogen exposure is life shortening and the impact falls both on those individuals who would have gotten cancer without the carcinogen exposure as well as the new cancer cases. This analysis is based on the interaction of age-specific tumor incidence rates and population survival in terms of age-sp...

background: welding can produce dangerous fumes containing various metals especially carcinogenic ones. occupational exposure to welding fumes is associated with lung cancer. therefore, welders in gas transmission pipelines are known as a high-risk group. this study was designed to determinate the amounts of metals cr, ni, and cd in breathing zone and urine of welders and to assess the possibil...