"HOUSTON — The nation's oil and chemical plants are spewing a lot more pollution than they report to the Environmental Protection Agency — and the EPA knows it.

But the federal agency has yet to adopt more accurate, higher-tech measuring methods that have been available for years.

Significant changes will not be seen for at least two more years, even though an internal EPA watchdog called for improvements in 2006 and some of the more sophisticated measuring devices have been used in Europe since the 1990s.

Records, scientific studies and interviews by The Associated Press suggest pollution from petrochemical plants is at least 10 times greater than what is reported to the government and the public.

Some European countries employ lasers, solar technology and remote sensors to measure air pollution, while the U.S. relies to a large degree on estimates derived from readings taken by plant employees using hand-held "sniffer" devices that check for leaks in pumps and valves."

Ramit Plushnick-Masti reports for the Associated Press with John McFarland April 22, 2010. [2]