W. Norman Aldridge

Abstract

Norman Aldridge was fascinated by the interaction of chemicals with living systems. He firmly believed that understanding how and why chemicals exert their toxic effects was fundamental to safety evaluation for chemicals used in the workplace or environment. He loved research with “an insatiable urge to make sense of things,” but also loved to apply the results to real-life issues. He encouraged his students, postdoctoral fellows, and visiting scientists from around the world to do the same. From the age of 16, Norman worked as technician in a dye works. His interest in toxicology started during World War II at the U.K. Chemical Defence Establishment at Porton, where he worked as an assistant to the renowned physiologist Professor Sir Charles Lovatt-Evans on practical problems of protection against chemical warfare agents. He proved himself a careful investigator, and in part-time study, he obtained a B.Sc. in chemistry and physiology. Norman cited Lovatt-Evan’s dictum, “I don’t think it will work, but you try it,” as a formative influence on his attitude, and subsequently it rubbed off onto many of his own students and colleagues. In 1947 John Barnes, who was also at Porton at that time, was appointed director of the Medical Research Council’s new Toxicology Unit located at Carshalton, Surrey. Barnes’ remit was broad: “Do something” to help face health problems that might arise as the postwar chemical industry burgeoned. He recruited Norman as the unit’s first scientific staff member. Over the next 40 years, Norman worked on the mechanism of toxicity of chemicals, including beryllium, organophosphorous compounds, acrylamide, organotin and organolead compounds, and pyrethroid insecticides. He drew visitors from all over the world but never built an “empire” —preferring to train, encourage, and liberate his students. In his early work, Aldridge established much of the basic enzymology on the interaction of organophosphorus esters with esterases. He classified these into A, B, or C esterases according to whether organophosphorus esters were hydrolyzed by them, were inhibited, or did not interact either way. With Elsa Reiner, Aldridge worked on the interaction of carbamate esters with acetylcholinesterase. Together they wrote a textbook entitled Interaction of Esterases with Esters of Organophosphorous and Carbamic Acids(Elsevier, North Holland, 1972), which is still a standard text. Aldridge initiated the search for the esterase that was thought to be associated with peripheral neuropathy caused by certain organophosphorus esters. He supported and encouraged Martin Johnson in his studies, which led to the discovery of what is now called