Substance abuse is especially hazardous in the case of many workers involved with providing services to the public, such as pilots, truck drivers, public transportation operators, air traffic controllers, nuclear power-plant operators, and other occupations directly affecting public safety.
Although alcohol has been traced to very few commercial aviation accidents, there is evidence that drinking among pilots is more widespread than the accident statistics indicate.
Since 1983 only 16 accidents in the USA involved drug or alcohol abuse on the part of the pilot. None of the accidents involved a major airline.