Two American authors argue that effort now and in future should concentrate on banning production of all POPs, not debating the exact risks to human health from residues in food.

Recent data show that since bans and controls on the use of POPs such as dieldrin, amounts in human breast milk have fallen over the years. What is also clear is a historical pattern to the discovery of the detrimental effects of well known POPs suspected of being harmful. The effects of PCBs and their true toxicity to the developing human fetus have been appreciated only after decades of research in a succession of increasingly sensitive animal models and is now established at a millionth of the dose determined in the earliest animal model. Similarly, it has taken the US Environmental Protection Agency 20 years to conclude that dioxin is so toxic that no safe level exists. Recent results have shown that dieldrin residues in fat in women are linked to risk of breast cancer, with only slightly larger amounts increasing the risk of the cancer, of aggressive tumours, and of dying.

The historical angle, therefore, provides all the evidence we need: if new compounds are persistent, lipophilic, and accumulate in tissues and the environment then we should act now to rid our environment of them, the authors say. The first candidates should be polybrominated diphenyl ethers, widely used as flame retardants, and synthetic musks.