Question

I have always enjoyed eating tuna fish. Unfortunately, a recent study of the mercury content of canned tuna found that chunk white tuna contains 0.68 ppm Hg and chunk light tuna contains 0.15 ppm. The U.S. Environmental Protection Agency recommends no more than 0.1 µg Hg/kg body weight per day. I weigh 64 kg. How often may I eat a can containing 6 ounces (1 lb = 16 oz) of chunk white tuna so that I do not average more than 0.1 µg Hg/kg body weight per day? cans/week

If I switch to chunk light tuna, how often can I eat one can?
can(s)/week

Answer 1

As per your body weight you can metabolise = 0.1*64
= 6.4 µg Hg per day

If we consider white chunk tuna,
One can of 6 ounces contains 0.68 ppm
= 0.68*6*0.0295 [ppm = mg/L, 1 ounce = 0.0295 L]
= 0.120 gm Hg
= 120 µg Hg

One can can be consumed over a period of = 120/6.4
= 18.75 days
Per day consumption = 6/18.75
= 0.32 oz

If we consider chunk light tune,
One can of 6 ounces contains 0.15 ppm
= 0.15*6*0.0295 [ppm = mg/L, 1 ounce = 0.0295 L]
= 0.02655 gm Hg
= 26.55 µg Hg

One can can be consumed over a period of = 26.55/6.4
= 4.148 days

Per day consumption = 6/4.148
= 1.446 oz