Mutagenic activity in urine samples from female tobacco habitues.

Since high incidence of oral cancer in India is associated with smokeless tobacco usage, mutagenic exposure of subjects habituated to a pyrolysed tobacco product, masheri (M) and tobacco-containing betel quid (Q) was evaluated in the present study. Urinary cotinine was estimated to ascertain tobacco exposure and urine mutagenicity to Salmonella typhimurium TA98 and TA100 was used to assess mutagenic burden. Urinary cotinine levels were higher in MQ users than in M users. Urine mutagenicity was evident in control samples only upon treatment with S9, beta-glucuronidase or acidified nitrite. However, greater exposure of users to mutagens resulted in additional direct mutagenicity to TA100.