Suppose a city’s water supply has 0.2 ppb (1ppb=10-3 mg/L) of polychlorinated biphenyls (PCBs) in it. Using the PCB oral slope factor (7.7 (mg/kg-d)-1 and the EPA recommended exposure factors

Suppose a city’s water supply has 0.2 ppb (1ppb=10-3 mg/L) of polychlorinated biphenyls (PCBs) in it. Using the PCB oral slope factor (7.7 (mg/kg-d)-1 and the EPA recommended exposure factors given in Table 6.14 below, (a) would be the individual lifetime cancer risk for an adult male residential consumer?(b) In a city of 1 million people, use this risk assessment to estimate the number of extra cancers per year caused by the PCBs in the water supply. “Extra” cancers refers to cancers caused by PCBs (as opposed to other causes such as smoking, etc.)(c) Assume the average cancer death rate in the United States in 193 per 100,000 per year. How many cancer deaths would be expected in a city of 1 million? Do you think the incremental cancers caused by PCBs in the drinking water would be detectable?