Cleaning Big Cities' Air "Not Rocket Science," Expert Says

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John Walke is director of the clean-air program at the Washington, D.C.-based National Resources Defense Council, an environmental advocacy group. He says technologies exist to clean the air in the U.S. and abroad.

According to Walke, existing pollution-control technologies include:

• So-called scrubbers, which typically use chemicals or water to remove sulfur from gases produced in coal-fired power plants.

• A process known as selective catalytic reduction, which relies on the use of chemicals like ammonia to start a reaction that removes nitrogen oxides from tailpipes and smokestacks.

• Baghouses—cloth bags used to filter gas streams3which can remove particulate emissions from smokestacks.

• High-temperature incinerators that can destroy toxic pollutants.

"It's not rocket science," Walke said. "Of course there are sophisticated variations on the basic technology, but those four have more or less been in use for the last 10 to 20 years and in some cases much longer."

Use of all these technologies simultaneously is important for combating air pollution, Walke added. Each technology targets a different kind of pollution, he said—there is no "single silver bullet."

But Walke says that political will for implementing such technologies is lacking.

"Merely requiring uncontrolled [coal-fired power] plants to adopt technologies that have been around for 10 to 20 years would solve air-pollution problems in this country, at least as far as smog and soot are concerned," he said.

The utilities industry has long fought such legislation, saying that refitting existing plants with modern pollution-control technologies would be prohibitively expensive, as would building new, more efficient plants.

For example, building new oil refineries would take up to ten years and cost three billion U.S. dollars, according to the National Petrochemical and Refiners Association.

"New grassroots refineries are not necessarily the best answer for the industry," ExxonMobil chairman Lee Raymond told CNBC television. "What we really need is a streamlining of the regulations."

Technology Transfer

According to Molina, industrialized nations such as the U.S. that currently have clean-air technologies ought to work with developing countries to reduce air pollution on a global scale.

"It will be very important for the industrialized world to collaborate very closely with the developing world, so that the rich countries do not just export old, obsolete, and dirty technologies," he said.

According to Walke, the process of transferring well-developed clean-air technologies to the developing world requires the U.S. to first mandate their use at home.

"History proves that [pollution legislation is] the strongest driver for technology development in this country," he said.

"And then history has further shown that those modern technologies developed in the U.S. are adopted abroad. The rest of the world has followed our lead."

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