In its March/April issue of 1998, the Ecologist magazine carried an article by Martin Walker which attributed to me bizarre beliefs about the causes of cancer that I do not hold and impugned my scientific independence.1 At the time, I chose to ignore this inaccurate article. With hindsight, however, this may have been unwise as the article has continued to be circulated and has, I understand, been referred to as if the contents were reliable by a member of one of the Chief Medical Officer of Health's advisory committees. It seems, therefore, necessary to put on record the incorrectness of some of the statements.

These include the following:

(1) “From 1979 to the end of his career, Sir Richard also received a very substantial yearly reward for research into cancer from General Motors.” This is untrue. In 1979, I received from President Carter one of three prizes for cancer research, which are donated annually by General Motors and given to different people each year. I have received no other money from General Motors and none of my research has been funded by General Motors.

(2) The statement that I have “always refused to accept the connection between man-made radioactivity and cancer” but have “always seen, for reasons best known to himself, natural radiation as a major cause of leukaemia and other cancers” is untrue. On the contrary, I have never distinguished between the effects of man-made and natural radioactivity (as, dose for dose, there are not any) and much of my research has been to assess the risk of cancer from man-made radioactivity.

(3) A question “why have Doll and his colleagues always insisted that only very high levels of man-made radioactivity were harmful?” is answered simply. They have not. On the contrary, I was one of the first (with Court Brown) to demonstrate an approximately linear relationship between (man-made) x irradiation and the risk of leukaemia and to suggest that the relationship held down to very low doses and I have consistently held to this view ever since. With Dr Sarah Darby and others, I have published one of the few papers providing any evidence of a possible leukaemogenic effect of radioactive fallout.

(4) “Doll's refusal to accept that any man-made chemicals can cause cancer and other serious health problems” does not accord with my tabulation of 20 chemicals as established causes of human cancer in Peto's and my paper on the avoidable causes of cancer (Doll and Peto, 19812) most of which are man-made nor with the results of my own research demonstrating the carcinogenic effect in humans of five chemicals or groups of chemicals, three of which were man-made.

(5) “Doll does not accept that air pollution of any kind may be regarded as a cause of lung cancer or of any other diseases of the respiratory tract” does not accord with my consistent belief that air pollution has been an important cause of chronic obstructive lung disease and my published estimate that, in previous decades, it may have been responsible, in conjunction with cigarette smoking, for about 10% of lung cancers in some big towns.

(6) “For Sir Richard Doll, . . ., the cancer rate is not increasing—nor indeed could it increase because lifestyles are becoming healthier” is another bizarre statement that in no way reflects anything I have ever said or could have said. Whether “the cancer rate” is increasing is a question of fact and I have repeatedly drawn attention to the recent increase in the age-standardised incidence of most of the cancers Walker lists as having increased (and, of course, to the decrease in the age-standardised incidence of several others, which he doesn't list). I have never thought or implied that lifestyle was the only cause of cancer nor that all aspects of lifestyle were getting healthier.

(7) “He (Sir Richard Doll) tells us too, against all the evidence, that the continued, unregulated and untested introduction of chemicals into our food, can do the land, the farmers, and ultimately the consumers, nothing but good” is equally bizarre. I have never said anything like this and believe the precise opposite.