Are sea vegetables safe?

I am excited about the health benefits of seaweeds [high in protein and vitamins], especially wakame, hijiki and kombu. But could these sea vegetables be affected by the same contaminants that poison the fish supply, and are "organic" ones available? —Theresa Pound

Pesticide residues can contaminate sea vegetables, along with sewage, oil, fertilizers and other chemicals that run off into the sea. But you won't find the elevated levels of dioxins, PCBs or mercury in sea plants as in fish, in whose body fats these pollutants collect and accumulate over time.

Oganic seaweeds are available. To qualify, according to the Organic Crop Improvement Association, a certifier approved by the U.S. Department of Agriculture, a seaweed's harvesting waters and sediment must be free of "significant comtamination from residential, municipal, commercial or industrial waste . . . ," although water testing is not required. Ask before you buy if seaweed beds are in clean water or near towns or industry, and if it is harvested using motorboats or rowboats.