These substances join a list of 12 other so-called persistent organic pollutants, or POPS, that are prohibited under a 2001 international treaty known as the Stockholm Convention. UN Environment ...

The protocols limit the emissions of sulphur oxides, nitrogen oxides and persistent organic pollutants. In 1999 the Gothenburg Protocol was signed by 49 countries of the Northern Hemisphere and ...

With the discovery of PCBs' environmental toxicity, and classification as persistent organic pollutants, their production was banned by United States federal law in 1978, and by the Stockholm ...