A Canadian team reports in this week’s Science that efforts to crack down on persistent organic pollutants (POPs) may have missed an entire set of them. Dioxin, PCBs, and DDT are considered among the most dangerous pollutants on the planet because they don’t break down easily, are highly toxic, and build up in the food chain. These chemicals persist in our body fat, and even miniscule amounts in food can add up over time and contribute to health problems such as cancer. More than 140 countries have endorsed the 2001 Stockholm Convention, which aims to banish a dozen POPs from the environment. The Convention’s target list is based on risk assessments of these POPs accumulating in fish food webs. But that assumption, the authors argue, could be missing chemicals that fish remove from their bodies but that mammals and birds don’t, due to their different respiratory physiology. One-third of the 12,000 or so organic chemicals on the market in Canada fit this new category. . . Whoa. Here comes Silent Spring, Summer, Fall & Winter. JULIA WHITTY