Inflated rates of opioid addiction among anesthesiologists may be caused by chronic exposure to low doses of aerosolized anesthetic/analgesic agents in the operating room. Such secondhand exposure produces neurobiological sensitization to the reinforcing effects of these substances, making later addiction more likely. This article extends findings that fentanyl and propofol are detectable in the air of the operating room and demonstrates that fentanyl is also detectable on surfaces in the operating room. Secondhand exposure could, therefore, occur by inhalation and skin absorption. Additionally, data show that many physicians with opiate addiction have a family history of addiction, suggesting genetic vulnerability to the effects of secondhand exposure. Other new data demonstrate that the rates of marijuana and tobacco smoking are much higher among opioid-addicted physicians, suggesting that prior exposure to THC (the psychoactive component of cannabis) or nicotine might increase vulnerability to secondhand effects. Suggestions for reducing secondhand exposure in the operating room are discussed.