Six weeks after the attacks that reduced the World Trade Center to a pile of rubble in lower Manhattan, dust and fires from Ground Zero are releasing toxic chemicals and metals into the air in quantities far greater than initially reported. Although U.S. and New York EPA officials have consistently downplayed the environmental hazards, government reports obtained by the New York Daily News show that the air and soil at Ground Zero contain levels of dioxins, PCBs, benzene, lead, chromium, and other toxins that often far exceed federal standards. The potential health effects for workers in the area and New York residents are unknown, but Paul Bartlett, an expert on PCBs and dioxins at Queens College, called the information “troubling” and said Ground Zero should be declared a Superfund site.