The "normal" lead content in human blood is about 0.40 part per million (that is, 0.40 g of lead per million grams of blood). a value of 0.80 part per million (ppm) is considered to be dangerous. how many grams of lead are contained in 6.0 × 103 g of blood (the amount in an average adult) if the lead content is 0.62 ppm?