"Whatever [conclusion] you want to come up with, you can, if you blend the right cocktail of numbers," said Erin Mendenhall, outreach director for the health-advocacy group Breathe Utah.
A simple bar chart distributed to news media by Gov. Gary Herbert's office Feb. 6 similar to an analysis of data by The Salt Lake Tribune (see accompanying chart) showed about 11 percent of pollution can be attributed to industry, while 57 percent can be pegged to vehicles and 32 percent on homes, small businesses, buildings and the other activities of day-to-day life.
Advocacy groups spent weeks doing their own calculations to shoot down those statistics.
Brian Moench, president of Utah Physicians for a Healthy Environment, said his group's experts have determined that Kennecott Utah Copper alone is actually responsible for up to 36 percent of area pollution.
Utah Division of Air Quality Director Bryce Bird explained the graphic given out by the governor's office was meant to answer the question of that smoggy February day: What are the sources behind this winter's pollution episodes?
Moench accused the state of misleading the public in its graphic by not making it clear that the 11 percent refers only to winter smog, while the copper-mining company's year-round emissions are higher. The doctor's group filed suit last year to block Kennecott's planned expansion.
Kennecott, meanwhile, says its contribution to pollution during the inversion season is just fractions of what Moench estimates. While its coal-fired power plant is shut down for four months each winter, Kennecott's emissions are about 3.8 percent of the valley's total. Annually, it's 5.8 percent, said spokesman Kyle Bennett.
Moench's group and the state differ on other data.
An infographic published Friday on the Facebook page of Utah Physicians for a Healthy Environment was headlined: "Utah: Worst air pollution in the country."
That was based on the Environmental Protection Agency's AirNow page, which maps the nation's air pollution daily. That map had at least one Utah county on its list of top five polluted counties for 35 days so far this year. Some days, Utah counties swept the nation's top five.
At the same time, there's another way to make the "worst-air" comparison, also using EPA data, that shows Utah's pollution in a less damning light.
Skipping 2012, which logged atypically low pollution levels, Salt Lake County in 2011 had 15 days when monitors recorded pollution at levels considered unhealthy for sensitive populations like the very young and very old. Cache County had eight and Utah County had five.
Meanwhile, Riverside County in California had 122 unhealthy days that year, and 14 other California counties had more high-pollution days than Salt Lake County. Even New Mexico's Doña Ana County had more than double the number of high pollution days than Utah's most populous county.
The conflicting storylines have left many feeling baffled about the true nature of the problem and solutions.
"Our air quality is an extremely complex problem, and it's going to require a lot of careful thought," said Kathy Van Dame, a member of the Air Quality Board and policy coordinator for the Wasatch Clean Air Coalition, who detailed the data controversy in an online Q&A.
"Uncareful assertions don't help us focus on the real problem, the simple problem of improving our air quality."
The bottom line, Moench says, is that Utahns won't stand for being admonished to pollute less while government allows industry to pollute more.
"That won't sit well with the public," he said, "and it won't succeed."
For its part, Kennecott's Bennett notes that the mining company's emissions will go down if the mine expands, thanks to updated equipment and procedures such as low-exhaust trucks, improved dust control, anti-idling practices and natural-gas rather than coal-fueled power.
"In the end," said Bennett, "we need to find solutions, implement solutions."
That is one thing that everyone seems to agree on, no matter what data they embrace.