Japanese shares plummeted 2.2 per cent to this year\'s lowest level Tuesday after heavy losses on European markets as investors were concerned about a global economic slowdown. The benchmark Nikkei Stock Average lost 193.89 points, or 2.21 per cent, to 8,590.57, the lowest since April 2009. The broader-based Topix index was down 14.62 points or 1.93 per cent at 741.2, according to a report of the German Press Agency \"DPA\".