How will Oregon clean up diesel air pollution?
Judy Woodruff: Two years ago, Volkswagen admitted to essentially cheating on emissions standards with diesel vehicles.
As part of a nearly $3 billion settlement, Volkswagen was required to establish a fund that could be used by states to reduce air pollution, specifically from diesel exhaust.
States are now figuring out how to spend their share of that settlement.
Special correspondent Cat Wise reports now from Oregon on efforts to reduce diesel exhaust there.
Her story is part of our Breakthroughs reporting for our weekly series on the Leading Edge of science and technology.
Cat Wise: Portland, Oregon, is booming. More than 20 cranes dot the skyline. Much of the heavy-duty work on construction sites and freeways, rivers, train tracks, in Portland and throughout the country is powered by diesel engines.
Diesel exhaust is toxic. It's been classified as a human carcinogen by the World Health Organization, and it's a contributor to climate change. Since 2007, new on-road vehicles have had to be built with emissions controls that greatly reduce, as much as 95 percent, the sooty mix coming out of diesel tailpipes.
For off-road equipment, the same rules phased in around 2014. But there are no regulations for the estimated several million older diesel engines still in use, and they can run a very long time.
In Oregon, their impact on air quality has been the focus of one dedicated scientist, who has turned her family station wagon into a lab on wheels.
Linda George: Diesel particulate matter is one of the air toxics that didn't get regulated in the Clean Air Act. So it's part of the unfinished business of the Clean Air Act.
Cat Wise: Linda George is an atmospheric chemist at Portland State University who is studying diesel levels in the city's air.
Linda George: What we're doing is driving around with an instrument called an Aethalometer. And an Aethalometer basically measures black carbon, which is a surrogate for diesel particulate matter.
Sometimes, when we have had it set up so we could see the instrument while we're driving, which is probably not too safe. But that was when we really discovered the construction equipment,you know, driving by construction sites, saying, whoa.
Cat Wise: She's had some whoa moments because there have been a lot of questions about how much diesel exhaust is actually in the air. Computer models have been the main tool used in Oregon, and in most states, to estimate diesel pollution. Those models predicted elevated levels throughout the Portland area.
But some have questioned their accuracy. George says her instruments largely confirmed the models, and found even higher periodic spikes in some areas.
Linda George: I set out to try and make measurements to really ground-truth these models. So what we have seen so far is that the diesel particulate matter measured in the city of Portland are above the health standards set by the state just about everywhere.
And then, if we look at areas where there's a lot of activity, like near a train or by construction equipment, we see really elevated levels, surprisingly elevated levels, 10 or 100 times higher than the standards.
Cat Wise: Those high levels in some areas can have an impact on public health. It's estimated as many as 400 Oregonians die prematurely every year from exposure to diesel exhaust, and overall health and welfare costs can be as much as $3 billion annually.
Some groups, though, are impacted more than others. A 2014 county report found diesel pollution is two to three times worse for minority communities.
Alex Mijares: You can see multiple semi-trucks coming off and on these highways. And just every time they rev their engines, and a puff of black smoke comes out, and it's just — it's just really gross.
Cat Wise: Twenty-seven-year-old Alex Mijares is one of those concerned about diesel exhaust. He lives in Tualatin, just outside Portland, in an apartment building near two busy freeways.
Alex Mijares: At least a mile, mile-and-a-half radius around our freeway exits are all low-income apartment buildings, where, you know, the populace are mostly Hispanics or Pacific Islanders. I'm worried for a lot of kids around here. I have lots of friends. They all have young children.
Cat Wise: Here in Oregon, there's been a growing awareness and concern about diesel exhaust and its impacts on human health. But the issue has taken on more urgency in the past year in the wake of the V.W. settlement. The state expects to get about $70 million in funds to help it clean up its air, but there's a big debate going on now about how best to spend that money.
Michael Dembrow: We're strapped budgetarily. And so the V.W. money came at a very opportune time.
Cat Wise: Michael Dembrow is a Democratic Oregon state senator whose district includes parts of Portland. Last year, he introduced a bill that, among other things, would have used V.W. settlement funds to help owners retrofit older engines or buy newer models.
Michael Dembrow: We know that the trucks that are going interstate and that are owned by the larger, wealthier companies are dealing with this problem. But those that are owned by smaller companies, minority, women-owned, are having a real challenge, because the new trucks are more expensive.
And as far as construction equipment, we just don't know.
Cat Wise: That's because the state doesn't have a license or registration system for off-road diesel equipment like tractors and backhoes.
Dembrow says his ultimate goal is for Oregon to do what California did a decade ago, require older diesel engines to be phased out or retrofitted. California is the only state which has enacted regulations for older diesel vehicles.
Michael Dembrow: To make this change so that our trucks are where California is today, we will have to prioritize. We don't have enough money to help everyone. But , certainly, we will want to use any funds that we have to help those companies that most need the help.
Cat Wise: But Senator Dembrow and his allies face an uphill battle. His original bill was largely gutted in committee after opposition from industry groups and some lawmakers, who raised a number of concerns.
A compromise was reached to use some of the V.W. funds to clean up the state's school bus fleet, but it's estimated that upgrading the entire fleet of older diesel vehicles throughout Oregon could cost hundreds of millions of dollars.
Some owners of older diesel vehicles, like Sandora Morsette, who operates a 1997 dump truck, worry those high costs might fall on them if new regulations are passed. Morsette supports efforts to clean up the air, but she wants lawmakers to be careful about implementation.
Sandora Morsette: I think that they should really consider how it's going to impact us. People just want to start the business to make money. And they don't think about making their truck perfect. They think about making their next paycheck. That could make or break their business.
Cat Wise: Kevin Downing is well aware of arguments on both sides of the issue. He's the state's clean diesel program coordinator. We met up with him on the lot of a local excavating company, where he used a white pillowcase to show just how much soot spews out of old engines.
Kevin Downing: All right, this is what's going up in the air and people are breathing it. We're trying to go from this to this. And it's possible to get trucks to run like this.
Cat Wise: Downing has been in charge of a small voluntary program that's used federal dollars, and some state dollars, to nudge owners like Ron Roth to scrap their old vehicles. On the night we visited, Roth was doing just that.
Instead of selling this 1994 truck for about $35,000, one of his workers burned a hole in the engine and cut the frame, so it could never be used again. And Roth got a check for nearly double that amount from the state.
Ron Roth: It's definitely a win for me, because I'm getting rid of it either way, but somebody else didn't get it. So now it's off the road.
Kevin Downing: We're using taxpayer money, $60,000, to put into encouraging scrapping an old truck and getting a new truck in. We're getting a return of about $30,000 to $40,000 a year in avoided health effects. That's an incredible investment of money.
Cat Wise: For her part, Portland State Professor Linda George says a better scientific understanding of diesel exhaust is vital to help inform the public policy debates.
Linda George: On a political level, models get dismissed as just being models, but what's really powerful is having models combined with measurements to really nail down what is going on.
Cat Wise: Later this year, the state is planning a one-time inventory of all off-road vehicles, and advocates of stricter diesel regulations say they will introduce new legislation.
For the PBS NewsHour, I'm Cat Wise in Portland, Oregon.