Nonprofit The Mercury Policy Project of Montpelier, VT is one of the consumer groups striving to reduce the amount of mercury in the environment. The group tested 59 samples of foil-pouched and canned tuna from 11 different states for mercury levels and found that some samples were dangerously high. Fish is touted by representatives from the National Fisheries Institute for its omega-3 fatty acids, but a growing body of research indicates that popular species might be contaminated with carcinogens. While tuna may not be the most popular item on school lunch menus, The Mercury Project sees the risks as too great to not make changes. Some plant-based sources of omega-3s include flax, hemp, and chia seeds.