Effect, carcinogenic synergic

As many metal compounds exert a rather weak mutagenic effect, their carcinogenic action cannot be explained by this effect alone. However, in several cases, indirect genotoxic effects - namely synergism with known mutagens - may be one reason for their tumorigenicity. 

Some materials cause genetic changes that can cause cancer (carcinogen), mutation (mutagens), and birth defects (teratogens). These effects are often hard to document due to latency periods and synergisms. 

Tobacco smoke. Tobacco smoke produces particulate matter that acts as an adsorption site for toxic vapors)26 In addition to particulates, tobacco smoke produces more than 4000 individual toxic compounds, including 43 known carcinogens. 27 Many of the toxic effects of tobacco smoke that have been established empirically cannot be ascribed to individual compounds in that smoke. With more than 4000 different toxins, the number of mixtures possible is incalculable. Numerous examples of synergism between tobacco smoke and other toxicants have been identified. These include tobacco smoke and asbestos or other mineral fibers, I28 29 alcohol, I30 31 organic solvents, 32 biological... 

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