Japanese shares dropped 1.8 per cent Monday as investors were concerned about the health of the US economy and export-oriented issues were pulled down by a strong yen. The benchmark Nikkei Stock Average lost 166.28 points, or 1.86 per cent, to 8,784.46 while the broader-based Topix index was down 13.96 points, or 1.81 per cent, at 755.82. Exporters such as Sony Corp, Canon Inc and Toyota Motor Corp fell sharply as the yen rose against major currencies, according to a report of the German Press Agency \"DPA\". Sony plunged 4 per cent, Canon dropped 2.5 per cent and Toyota plummeted 2.62 per cent. A strong yen makes Japanese goods more expensive overseas and hurts repatriated earnings. On Friday, the Dow Jones Industrial Average plunged 2.2 per cent after US unemployment held steady at 9.1 per cent for August and was virtually unchanged since July. On currency markets at 3 pm (0600 GMT), the dollar traded at 76.72-74 yen, down from Friday\'s 5 pm quote of 76.83-84 yen. The euro traded at 1.4148-4149 dollars, down from 1.4232-4234 dollars Friday, and at 108.55-59 yen, down from 109.34-36 yen.