For mercury the highest concentration obtained for this study was recorded in Nampa tuna fish (0.2 lg g1 wet weight). An adult who weighs 60 kg must consume about 1500 g of the Nampa tuna (150 g per can) which is about ten (10) cans per week in order to accumulate 300 lg of mercury in a week which is the limit set by FAO/WHO Expert Committee on food additives. This means that for the other species of fishes which have lower concentrations more than 10 cans per week will have to be consumed in order to accumulate that much of mercury in an adult which is highly unlikely for an individual. Moreover the eating habits of Ghanaians are such that the consumption rate of canned fish is quite low even though data on the rate of consumption of canned fish in Ghana is
unavailable. For cadmium the highest concentration obtained for this study was recorded in Rising star tuna fish (0.45 lg g1). An adult who weighs 60 kg must consume about 933 g of the Rising star tuna fish (155 g per can) which is about six (6) cans per week
in order to consume 420 lg of cadmium the limit set by the joint FAO/WHO Committee (2004). Even though it is possible for one to consume six (6) cans of the tuna each week, most Ghanaians prefer taking their fish in other forms such as fried, salted etc. So the rate of consumption of canned fish is low even though data on the rate of consumption of canned fish in Ghana is unavailable.The highest lead concentration was recorded in B.B. sardine (1.44 lg g1 wet weight). A 60 kg adult must consume about
1042 g of the B.B. sardine (215 g per can) which is about five (5)cans per week in order to accumulate 1500 lg of lead concentration which is the limit set by the joint FAO/WHO Committee (2004) for 60 kg weight of an adult. Again, it is possible for one to consume that much of can fish per week but the eating habits of Ghanaians as discussed before is such that the consumption rate of canned fish is quite low even though data on the rate of consumption of canned fish in Ghana is unavailable.