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Grand Canyon Getting Lost in the Haze

Environment: Air pollutants come from as far away as Los Angeles. Effects range from a barely perceptible veil to completely obscured views.


GRAND CANYON NATIONAL PARK, Ariz. — Jean Davis and her husband, sons and grandchildren ventured here from Iredell, Texas, expecting a spectacular view.

Her first glimpse of the Grand Canyon was hardly a disappointment.

"It's awesome. It's more than I expected. It looks like a picture," she gushed.

But what Davis and most of the 5 million others who visit the canyon each year don't realize is that even this symbol of pristine outdoor America is facing air pollution problems.

Look closely and you often can see a milky film of haze.

Western power plants, freeways in Los Angeles and even lawn mowers in Las Vegas are contributing to a problem so serious that the park has its own air quality expert.

Air quality coordinator Carl Bowman spends his days checking aerosol samplers, acid rain collectors and an apparatus called a transmissometer, which directly measures the visibility from the canyon's edge to its bottom.

"There's at least some visibility impairment [every day]--anything from a light veil to real disgusting," Bowman said.

One day this summer was about as bad as he's ever seen it, he said. The normally reddish walls of the canyon had a bluish gray tint, and the far rim wasn't visible at all until a thunderstorm pushed the bad air out.

In the 1960s and '70s, the pollution started seriously clouding the canyon, and since then, it's been an uphill battle to clear the air and the view.

For a long time, large coal-fired plants in Arizona and neighboring states were considered the main source of pollution, but most have been or are in the process of being cleaned up. Now Bowman and other air pollution experts face the task of tackling even tougher problems--those associated with the region's growing population.

"Improvements we were making on those big sources are being gobbled up by more cars, leaf blowers and other sources," Bowman said.

What can be done at the canyon to get rid of the haze is limited, he said. The pollution pours in from all over the region.

Cars, barbecues, lawn mowers, boats--machines all over the West--are spewing pollution into the air, and it's wafting its way all over the region, including the Grand Canyon.

It makes sense that forest fires are cited as major canyon polluters, but the list also includes pollution blown in from Mexico and even dust kicked up by cars on roads--paved and unpaved--throughout the Colorado Plateau.

Rick Moore of the conservation group Grand Canyon Trust said researchers know that sulfur dioxide from a power plant 75 miles away makes its way to the canyon, but they don't know how much of it creates haze. For sulfur dioxide to have a visible impact, it must interact with other chemicals, creating molecules large enough to obscure the view.

Bowman said scientists can tell that pollution from as far as Los Angeles is dumping into the canyon. One particular chemical comes only from Los Angeles, allowing air quality experts to trace pollution from there.

That chemical can even be traced in a pattern of up five days and down two days, paralleling a workweek.

Scientists have tested a variety of possible pollution sources at the canyon rim, including barbecues. They could not find any detectable difference in pollution levels when barbecues were in use.

Grand Canyon officials have also tested ponderosa pines and other sensitive plants to see how they are holding up, because they tend to be especially vulnerable to some pollutants, Bowman said. So far, no damage has been detected.

Meanwhile, to address the regional problem, western states and American Indian tribes have made recommendations as part of the Grand Canyon Visibility Transport Commission on how to reduce haze.

The commission is recommending efforts to reduce car emissions, limit when intentional fires are started on government land and create an emissions-trading market. A regional emissions market would allow companies that emit less than their permitted pollution to sell their remaining pollution allotment to other companies.

Although the pollution at the Grand Canyon is relatively low compared to a large city, it still has officials concerned.

"Visibility is like the old miner's canary. It's the first thing to go," Bowman said. "The problem with clean air is that when you add a little pollution it really hurts visibility. It doesn't take much to trash it."


Sources of the Haze

Major sources of pollution around the Grand Canyon:

Power plants: Traditionally, power plants have been a major pollution contributor at the Grand Canyon. One plant, the Navajo Generating Station in Page, Ariz., long disputed the federal government's contention that its emissions were harming the Grand Canyon's air. It has begun putting scrubbers on its smokestacks to significantly reduce the amount of emissions.

Road dust: Recent studies by the Grand Canyon Visibility Transport Commission indicate that dust kicked up by cars on paved and unpaved roads throughout the Colorado Plateau are a significant contributor to haze.

Mexico: Industry emissions from Mexico also were identified by the commission as being a major pollution contributor.

Forest fires: Both wildfires and prescribed burns, which are fires set intentionally, act as seasonal contributors to pollution.

Associated Press

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