The author statistically reviews the common forms of cancer in humans in relation to the British population. He then discusses the relationship between these cancers and the chemicals in the environment, with particular reference to those chemicals used in industry such as dyes, additives, solvents, as well as foods and pharmaceuticals. Natural carcinogens are also discussed in brief, including those derived from fungi, and the synergistic effects of some chemicals on weak carcinogens to enhance their action is also brought out. Formaldehyde as a carcinogen is investigated in the light of more recent studies, its possible carcinogenicity in combination with other chemicals is briefly mentioned. -- AATA