Salmon Not Safe?
Note that "salmon containing toxic chemicals" translates to farmed salmon. The story specifically says farmed Atlantic salmon, but it should be noted that some species of Pacific salmon are also pen-raised and fed 'fish chow' -- basically ground-up fish that have concentrated environmental contaminants like dioxins and PCBs.
Honestly, it's all very confusing, as most cost-benefit analyses and health risk assessments are. (Tell me again, how many glasses of wine per day are supposed to be good for me? Is that white or red? And, wait, what if there's alcoholism in the family?) To further complicate matters for the consumer, the extent of toxicity in salmon varies considerably and has much to do with where the salmon are raised. Farm-raised Chilean salmon, for example, is said to have fewer toxins than salmon reared in pens in Scotland and British Columbia.
The Star article restricts its focus to health risks, but pen-raising salmon is also a bad deal environmentally speaking, for a wide variety of reasons. And that, at least, should help simplify your choice at the fish market. As a rule of thumb, if you want healthy salmon -- healthy for both you and the environment -- buy wild. And, for those who think you can't afford it, here's a tip: consider canned salmon, the vast majority of which is wild pink salmon. It's cheap and has less mercury than tuna.