He was also one of the first people to develop the strategy of harm reduction. He has argued that harm reduction approaches to addictions, HIV or other public health concerns are instances of the traditional public health practice of tertiary prevention—prevention of deaths or disability that might otherwise occur due to a health problem. Duncan first applied this approach in his work with adolescent drug abusers in Houston, Texas in the early 1970s and soon afterward with heroin addicts. In 1983 he and Robert S. Gold published an argument for this approach, which they then called "cultivating drug use", using the word cultivating in its sense of the elimination of weeds and promotion of healthy growth.