Bloomberg / Vienna/new Delhi November 12, 2008, 0:05 IST French authorities made headlines last month when they said as many as 500 sets of radioactive buttons had been installed in elevators around the country. It wasn't an isolated case. Improper disposal of industrial equipment and medical scanners containing radioactive materials is letting nuclear waste trickle into scrap smelters, contaminating consumer goods, threatening the $140 billion trade in recycled metal and spurring the United Nations to call for increased screening. Last year, US Customs rejected 64 shipments of radioactive goods at the nation's ports, including purses, cutlery, sinks and hand tools, according to data released by the Department of Homeland Security in response to a Freedom of Information Act request. India was the largest source, followed by China.