POPs

are Persistent Organic Pollutants such as PCBs, DDT, Dieldrin and Dioxins. The text of a Protocol has been agreed under the UNECE Convention on Long Range Transboundary Air Pollution to control POPs emissions using process and product controls
Found on http://www.epaw.co.uk/EPT/glossary.html

POPs

Persistent organic pollutants, a group of PTBs which are capable of long-range transport and deposition; they are believed to be transported primarily in the atmosphere. These have global effects. Most are already banned in Western Europe but some are still in use in developing countries. The POPs include the following 12: PCBs, dioxins and furans,
Found on http://www.eurochlor.org/mainglossary

POPs

Probability of Precipitation.
Found on http://ggweather.com/glossary.htm
No exact match found