From The New York Daily News: a Bronx mother of two is planning to sue New York City to force it to clean a school building contaminated with polychlorinated biphenyls (PCBs). Naomi Gonzalez says she plans to file a notice of intent to sue over what she says is the city's refusal to remove caulk contaminated with PCBs from her children's school, Public School 178 in the Bronx. Lab tests commissioned by The Daily News found PCB contamination was more than 2,000 times higher than the threshold for toxic waste. Tests of nine public school buildings last year revealed high levels of PCBs at six of them. The highest levels were found at Manhattan's PS 199, measured at 225,000 parts per million. Anything with more than 50 ppm of PCBs is considered toxic waste under federal law.