Roughly one in four U.S. households have soil exceeding the new U.S. Environmental Protection Agency’s lead screening levels of 200 parts per million (ppm), halved from the previous level of 400 ppm, a new study found. For households with exposure from multiple sources, the EPA lowered the guidance to 100 ppm; nearly 40% of households exceed that level, the study also found. Roughly one in four U.S. households have soil exceeding the new U.S. Environmental Protection Agency’s lead screening levels of 200 parts per million (ppm), halved from the previous level of 400 ppm, a new study found. For households with exposure from multiple sources, the EPA lowered the guidance to 100 ppm; nearly 40% of households exceed that level, the study also found. Earth Sciences Environment Phys.org – latest science and technology news stories