Months after residents of a Turtle Bay building found their apartments coated in a layer of dust, an environmental testing firm found "highly elevated levels" of a carcinogen inside the E. 47th Street condo tower. A toxic substance found in mortar called crystalline silica got into apartments while laborers did facade work at the L'Ecole building at 212 E. 47th Street, according to an attorney for tenants who have filed suit over the incident. "It was like there had been a snowfall," said Steven Rosenhaus, who suffered breathing trouble and eye irritation after his 20th-floor apartment was blanketed in the the powder. According to the Post, building management has denied any wrongdoing in court documents.