Sixteen years ago Seattle’s skies were so polluted that environmental regulators declared the air “unhealthful” - or worse - several times a month.
Now skies are so clean that the Emerald City hasn’t had a single day in four years that violates federal air standards. Tacoma and Everett have been violation-free even longer.
We can breathe easier thanks to cleaner cars and cleaner industrial smokestacks. Homeowners are turning in their smoky wood stoves - once touted as environmentally hip - for fake logs and gas-burning fireplaces.
Does this mean the bluest skies you’ll ever see are in Seattle? Not really.
Despite an impressive drop in pollutants, visibility in the region has mysteriously declined. Health problems linked to air quality also persist. And air pollution is more diffuse as suburban sprawl and clogged freeways spread bad air throughout the region.
Nonetheless, some of the most harmful air pollutants of a generation ago have been sharply reduced.
Lead in the air is down more than 90 percent. Carbon monoxide and particulate emissions have been cut in half over the last decade in the Puget Sound region.
Public policy efforts to halt pollution, spurred by increased public sensitivity to environmental degradation, dramatically improved the air we breathe.
Few images of environmental degradation are more vivid than the industrial smokestack spewing a pillar of dark contaminants into the sky.
Easy to identify and monitor, industrial polluters were among the first targets of environmental regulators. Some aging smokestack companies went out of business, but most invested heavily to meet federal and environmental standards.
For example, the pulp and paper mill at the edge of downtown Tacoma used to belch 40,000 to 50,000 pounds of particulate matter - the equivalent of a railroad car of soot - into the air daily, according to estimates by the state Department of Ecology.
The daily emissions now are less than 1,000 pounds.
The mill’s decline in sulfur compounds, the stuff that helped produce the legendary “aroma of Tacoma,” was even more dramatic. The mill now releases less than one-hundredth of what was put in the air 25 years ago, state regulators said.
To achieve these gains, it took a $200 million investment in new boilers and innovative recycling technology by the Simpson-Tacoma Kraft Co., which bought the plant in 1985.
Similar gains have been made across the state, resulting in an 80 percent reduction in emissions by traditional smokestack industries, according to Ecology Department estimates.
After targeting industry, regulators changed their focus to other sources of air pollution: cars, wood stoves and outdoor burning.
Wood stoves were a surprisingly big source of pollution, accounting for as much as 80 percent of smog in some residential areas.
Consequently, the state now bans outside burning on high pollution days and imposes the nation’s toughest production standards for wood stoves.
Many wood stoves on the market today use catalytic converters and insulation materials designed by NASA for space travel. Particulate matter spewing from the high-tech stoves is less than 2.5 grams an hour - the weight of a couple of paper clips.
The graying of America has also reduced smoke from wood stoves.
“The baby boomers that were ready to play Little House on the Prairie have moved on and don’t want to split wood any more,” said Larry Altose, a Department of Ecology spokesman.
Easy-to-light gas stoves and fireplaces now outsell wood-fueled ones, industry officials confirmed.
Wood smoke today accounts for 10 percent of the state’s air pollution, half as much as a decade ago.
Just as wood stoves are cleaner, so are cars.
From catalytic converters to onboard diagnostic computers, high-tech emission controls have become required equipment for cars produced today. The result is a reduction of 90 percent or more in hydrocarbons, carbon monoxide and nitrogen oxides, pollutants known to cause health problems.
The federal government also outlawed the use of leaded gas, while mandating vehicle inspections where air standards are in peril.
But regulations haven’t addressed the core problem: our addiction to driving.
The number of miles traveled in the region is increasing two to three times faster than population growth.
On a work day, Altose said, cars in King, Snohomish and Pierce counties now travel 60 million miles, a distance that could take us more than two-thirds of the way to the sun.
“The technology has allowed us to have significant impact without changing our driving habits,” he said.