Perhaps the most widespread and least publicized form of drug abuse, inhalant abuse is only now beginning to gain the attention and concern of middle school administrators, who are becoming increasingly aware of its extent and the damage it can cause. The National Institute on Drug Abuse defines inhalants as "breathable chemical vapors that produce mind-altering effects." Some of the most commonly abused substances are adhesives, aerosols, anesthetics, cleaning agents, and solvents. The 1999 Monitoring the Future study showed that 1 in 10 eighth graders, 1 in 15 tenth graders, and 1 in 20 twelfth graders had used inhalants in the preceding year. Use by African-American students appeared to be least prevalent. Among eighth graders, females consistently had a slightly higher annual prevalence rate, a trend that did not hold for the higher grades. The low cost and easy availability of inhalants make them attractive to some students. In addition, inhalants can be used quickly, with no specific paraphernalia, and with little risk of detection. Figure