Column: The dirty history of L.A.’s smog


If you think the smog is bad now, you should have been here 50 years ago. Or just wait – because it may come back. The Trump administration has stripped California of the power the state has had for more than 50 years ago to help keep smog at bay by setting stricter vehicle emission rules. That power has delivered cleaner air and fewer health complications to generations of Angelenos. And now that power could disappear into thin – and filthier – air. Ed Avol is a professor of clinical preventive medicine at USC’s Keck medical school, an engineer by training, a devoted 5K runner who’s breathed L.A.’s variable air for some 50 years, and lays out how this future air could look like past.


What crossed your mind when you heard that the auto emissions restrictions in Los Angeles and California might be rolled back?

It’s sort of like a deja vu. When I was a child here growing up, there were days, weeks, where you couldn’t see the mountains, where it is hard to breathe. We were kept from playing outside on the playground during school. And I think nobody wants to go back to those days. Seeing the tremendous progress that has been made being hampered by federal policies is really I think going in the wrong direction.


If smog were a recipe what would be the ingredients?

You take one part little pieces of dirt floating in the air, which we call aerosols. Then a couple of parts of various noxious gases, including those you can both see and can’t see, and you stir them all up and mix with several hundred other chemicals and cook with some heat for a couple of hours, which is the sunlight, and you get Los Angeles smog.

Are we in Los Angeles stuck with air pollution in part just because of the topography of the mountains and the basin and the ocean? How does that work?

It’s certainly a part of it. Hundreds of years ago, before we had the millions of people that live here and the millions of cars that drive around, this was the known as the Valley of Smokes, partially because with the high mountains and the onshore breeze and the stagnations that occurred with the tribal fires and Indian activity and so forth, and the occasional dust.

There were many days here that were hazy even without all the people. But certainly all the people, all the activities, all the urbanization has added to this.

So now -- not wholly because of the people but certainly in addition -- the natural background and the manmade activities have contributed greatly to our problem here.


You may know what L.A.’s epiphany was and when it was when, L.A. looked around and said, God, this is really bad, and we can do something about it.

In the early and mid ‘40s, both during the Second World War and coming back from it, people were really struck by what looked like continually cloudy days in Los Angeles, except it wasn’t. It was just the poor quality of the air that was a hazy, acrid, smelly, burning presence. And people thought, this is not good. We have to do something about it.

So California got a relatively early start trying to deal with some of the problems here. We’ve been at it for the better part of 70 years now.

Overall, when you look at the state of health of people in Southern California -- of young people in particular -- what have you seen change over the years and what are still your concerns?

We know a tremendous amount about the effects of air pollution, both short-term and long-term effects on people. Certainly the lung is the primary organ for which there are effects and we know a lot about it. But it goes far beyond the lungs, because once it crosses the air blood barrier in the lungs, it gets into the blood in the circulatory system and then essentially the contaminants could go anywhere in your body.

So it’s not surprising that we see effects in the lungs, in the heart, in the metabolic system, in the brain. It starts in the lungs and it continues on in terms of cardiovascular disease, acute respiratory infections, even in terms of being linked to diabetes and obesity. It’s actually been connected with some neurological problems in terms of younger children being able to pay attention and learn in school. Most of my work has been looking at children and early-life development, but later on in life it turns out that air pollution has a role to play in terms of thinking about Alzheimer’s and dementia and the rate of neurological decline.


So this isn’t something you throw off as you get older, like allergies.

No. I think a way to think about this might be more like smoking. This is something that has a lifetime effect that builds and accrues, and it can affect the early start to what we might consider as a healthy start, or a less than healthy start, and then have impacts on your whole life.

You and your colleagues have found that among poor people, that people of color, who tend to live closer to roads and freeways, the results are particularly seen.

That’s right, and that’s a real injustice. It’s framed in terms of environmental racism, environmental injustice, environmental inequities. People in lower socioeconomic classifications don’t have the money to sort of buy their way out of a potentially less than attractive neighborhood and moving to a cleaner place with more parks, more greenery et cetera. That is causing a lifetime effect.

Is cleaner air a relative term anywhere in L.A. -- in Southern California?

When we started the children’s health study in the early 1990s to look at communities of thousands of children across California as they grew up, to understand something about the long-term impacts of air pollution on their health, we actually had to leave the Los Angeles region to try to find a place of lower pollution, a cleaner location, to compare them with those kids growing up in higher pollution areas.


What percentage of smog now is produced by cars -- because cars are cleaner, and the dirtier cars are getting aged out? What percentage still comes from factories or construction, when the Air Quality Management District has had rules in place on those for a while too?

That’s an interesting question. People sometimes forget or don’t fully appreciate that the issue of smog and air pollution was a success story, that there’s been tremendous strides made in the several decades that we’ve been fighting stationary sources that is sources such as boiler plants, factories, refineries, power generation plants -- things that don’t move. Those have been pretty tightly controlled for many years

But of course we have many, many millions of cars and we drive many, many millions of miles. And so even though the newer cars are immensely cleaner than the older ones – a car five years old is much dirtier than the newest cars – it’s just the natural turnover of the fleet in essence that’s cleaning up the cars that are on the road.

In Southern California, the cars last a very long time. It’s not uncommon to see cars on the road that are 30, 40, even 50 years old, and that means older, what we might call super polluters, are still on the road.

Everybody likes to have a nice, neat, new, shiny, clean car, that’s great for air quality. But again because we have so many millions, cars account for maybe 60% or 70% of the emissions and the air pollution problem. They’re not the only problem. The ships are a problem. The trains, the planes, the construction equipment -- all those things contribute to air pollution,

But certainly because of their sheer number and the breadth of activity, motor vehicle emissions are a major problem in Southern California.


Would doctors, would kids in school, would Angelenos notice a difference if the auto emission restrictions that have been in place for 50 years under this waiver -- if those were to end?

I think that’s the concern. It’s not going to turn over overnight. But the concern is that we’ve continued to push hard and make progress, and that if we relax and ease back on standards, ease back on the attempt to continually try to clean up the air, we’re going to start to see more and more days of higher pollution.

We’re starting to see a little bit of that now because of climate change, and the concern is that is if we stop working so hard to clean up mobile emissions, the air quality is going to slowly deteriorate again.

Is climate change chiefly why we have seen more smog, even smog alerts, I think, for parts of Southern California and the Central Valley?

It’s not the only answer but it’s part of it. Because we’re seeing more warmer days, you’re seeing more stagnant episodes. And when that happens, going back to this analogy of the cooking pot on the stove, we’re seeing more cooking taking place and more pollutants being formed and staying around longer, and so we’re seeing more elevation of pollution and in that case more days of [air quality] violations.

And just because we can’t see smog doesn’t mean it isn’t there.


That’s exactly right. Here in Southern California we are still in violation of two national ambient air quality standards: one, you can think of as small pieces of dirt floating around in the air they’re too small to see. And the other one is ozone. Now, ozone is a clear gas, so it might well be that you can’t see and it still might be in violation of the standards. We still violate the standards, which is to say, based on the best available science, we still think the air is not fit to breathe. So there’s still work to be done to improve the public health.

You were a runner in school. you’re still a runner of five Ks. Are you mindful when you do this of what’s in the air that you’re breathing that particular day?

Yes. I think that it’s important for everybody to get out and get exercise. We’re all too sedentary. We all spend too much time sitting around, and we all need to get out walk or jog or bicycle or swim or do these different options to get our exercise. That’s good for us.

But we need to be mindful, we need to be smart about when and where we exercise. Trying to avoid rush hour, not running along busy streets or riding our bikes or getting out and really exerting ourselves at the peak rush hours with a lot of traffic and emissions out there is a smart idea.

Are we smug about smog? Do we either take it for granted or figure we’ve already beaten that problem?

Many come to Los Angeles and say, How can you live like this. Now, the visibility is actually generally good, but we have had this creeping return of poor air quality, which is a function, ultimately, of urban land use decisions: how do we plan our cities? What are we going to accept. How do we make smarter decisions in terms of mass transit, in terms of public transportation, in terms of building, in terms of access and equity for all the population to have an equal chance to play and be safe and go outside and enjoy the recreational activities and have a livable, sustainable lifestyle?


If you do this, these will be health impacts of that. And hopefully, based on that, regulators and policymakers can make smarter decisions about where we should go to improve the quality of life for communities and population.

We all have an individual responsibility. Obviously there’s a collective issue, and we can all say, well, it’s too overwhelming. Whether I drive my car or not, whether I walk or not, it’s not going to make a difference in the overall air pollution problem.

But I tell my students, there’s an old African proverb that if you think that you’re too small to be part of the problem or any part of the solution, you’ve never spent a night with a mosquito.