Sir Richard Doll (1912-2005)

Credits:Corbin Grady Studio/Science Photo Library

Richard Doll was probably the most influential epidemiologist of the second half of the 1900s. Along with his colleague Austin Bradford Hill he published pioneering research that linked smoking with cancer and other serious diseases.

In the late 1940s, Doll joined a team led by Hill charged with investigating possible environmental causes for the increase in lung cancers across the country. Although pollution - possibly coal smoke or car fumes - was thought the most likely factor, close analysis of the statistics pointed to smoking as the problem. Hundreds of newly diagnosed cancer patients had been interviewed. Those whose diagnosis later proved to be wrong were found to be non-smokers, but those diagnosed correctly were almost invariably smokers.

Although their initial report of 1950 was met with scepticism, subsequent research could not be ignored. Doll would later affirm the linkage between smoking and coronary heart disease and nearly 20 more medical conditions. As well as smoking, he also investigated numerous other public health issues. These included the confirmation that even low levels of asbestos and radiation were dangerous to health. He also investigated the dangers of alcohol to the unborn baby and the potential side effects of the contraceptive pill.

Doll received many honours, including a knighthood, in his lifetime. But some controversy arose following his death when it was revealed that for several years he worked as a paid consultant for a number of leading chemical manufacturers. Some critics felt this amounted to a conflict of interests.