miscellaneous chemical carcinogens
Last reviewed 01/2018
Chemical carcinogenesis can come in a variety of forms which are not directly related to occupation or medical treatment:
- natural result of presence of organism or its product:
- some strains of Aspergillus flavus stored on grains or peanuts produce a toxin for hepatocytes - aflatoxin B1; in Africa and the Far East, the concentration of aflatoxin in the diet correlates with the incidence of hepatocellular carcinoma
- Helicobacter pylori produces a chronic gastritis that has been linked to the eventual development of gastric carcinoma
- dietary influence:
- provide substrates for the formation of carcinogens, e.g. nitrites and nitrates
- increasing the duration of carcinogen contact with stem cells by changing the dietary composition, e.g. low-residue diets which prolong transit
- varying the proportion of selenium and vitamins C and E in the diet, so influencing the amount of free radical production and hence gene damage
- pollution:
- air: when air pollution was more severe at the turn of the century, lung cancer was concentrated in urban areas
- water: weak relationship between the presence of halogenated hydrocarbons and pesticides and bladder cancer