Mikhail Gorbachev major campaign to limit alcohol consumption, which Gorbachev—who believed it would improve health and work efficiency—oversaw. His wife keenly supported the measure. As a result, crime rates fell and life expectancy grew slightly between 1986 and 1987. The reform had significant costs to the Soviet economy, resulting in losses of up to $100 billion between 1985 and 1990. Gorbachev later considered the campaign to have been an error. In April 1986 the Chernobyl disaster occurred; in the immediate aftermath, officials fed Gorbachev incorrect information to downplay the incident. As the scale of the disaster became apparent, 336,000 people were evacuated
Mikhail Gorbachev carried out only personnel shifts rather than structural change. Andropov encouraged Gorbachev to expand into policy areas other than agriculture, preparing him for future higher office. With Andropov's encouragement, Gorbachev sometimes chaired Politburo meetings. In April 1983, Gorbachev delivered the annual Lenin's birthday speech; this required him re-reading many of Lenin's later writings, in which the first Soviet leader had called for reform, and encouraged Gorbachev's own conviction that reform was needed. In May 1983, Gorbachev was sent to Canada, where he met Prime Minister Pierre Trudeau and spoke to the Canadian parliament. There, he met and befriended the Soviet