Then, they came for the airplanes…

Image: Michael Kelley
From the American Chemical Society: Heavy airplane traffic potentially a major contributor to pollution in Los Angeles

Congested freeways crawling with cars and trucks are notorious for causing smog in Los Angeles, but a new study finds that heavy airplane traffic can contribute even more pollution, and the effect continues for up to 10 miles away from the airport. The report, published in the ACS journal Environmental Science & Technology, has serious implications for the health of residents near Los Angeles International Airport and other airports around the world. 

Scott Fruin, D.Env. P.E., Neelakshi Hudda and colleagues note that past research has measured pollution from air traffic before, but most of these studies only sampled air within a couple of miles, at most, from airports. Not surprisingly, these analyses have found higher levels of pollutants, such as nitrogen oxides and small (ultrafine) particles less than 0.1 micron (about one-thousandth of the width of a human hair), that scientists attributed to airplane emissions.

This added pollution is potentially a major public health issue. Ultrafine particles, which form from condensation of hot exhaust vapors, are of particular concern because they deposit deeply into the lungs and can enter the bloodstream. The oxidative stress and resulting inflammation appear to play a role in the development of atherosclerosis (blocked arteries) and can make other health conditions worse, especially for people with existing cardiac or lung conditions including asthma.

Fruin’s team at the Keck School of Medicine and the University of Southern California suspected that residents near LAX, the sixth busiest airport in the world, were getting exposed to excessive doses of pollution from airplanes even farther from the runways than previous research had considered. During its busiest times, 40 to 60 jets take off and land every hour.

Over a period of 29 days, the scientists drove the area within 10 miles downwind of the airport to measure levels of air pollutants. The area included densely packed residential neighborhoods flanked by three major freeways.

They found that over a 23-square-mile area, particle number (PN) concentrations were double the background levels (that is, the PN concentrations without the LAX contribution). Over 9 square miles, levels were five times higher than background. And within nearly 2 miles east of the airport, PN levels were nearly 10 times higher. Based on other researchers’ calculations of PN levels from one of the local freeways, Fruin estimated that this is equivalent to 174 to 491 miles of freeway traffic. For reference, the entire area of Los Angeles County has a total of about 930 miles of freeways.

Based on their calculations, scientists concluded that within the area they found to have elevated pollution from the airport, automobiles contributed less than 5 percent of the PN levels. “Therefore, the LAX should be considered one of the most important sources of PN in Los Angeles,” the scientists state in the journal article.



The researchers acknowledge funding from the National Institute of Environmental Health Sciences and the Environmental Protection Agency. Fruin and Hudda collaborated with colleagues at the University of Washington.

The paper is freely available as an ACS Editors’ Choice selection at

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May 29, 2014 9:23 am

They should just get it over with and declare California a natural preserve and technology free zone.

May 29, 2014 9:24 am

In other news, water is still wet.

michael hart
May 29, 2014 9:25 am

Probably won’t be much support coming out of Hollywood for this one.
Also the “oxidative stress and resulting inflammation” tag is a pretty standard piece of speculation more typical of the science of diet fads. They just don’t know. So people’s imagination is free to wander in search of headlines.

Dale Monceaux
May 29, 2014 9:30 am

This is going to get very interesting. Air pollution from airports will be concentrated in areas with the highest airline traffic, which coincides with larger population centers, which coincides with heavy Democrat constituencies, which coincides with pro-environmental agendas.
Can’t wait for the proposed solution to this problem. It will likely be akin to the plant a tree in the rainforest so that I can pollute in Canada proposition.

May 29, 2014 9:32 am

A return to piston-driven planes is the obvious answer. Now, what was the question again?

Doug Proctor
May 29, 2014 9:34 am

The eco-green wants to keep everyone in a small city with a metro. They want the non-city walled off and kept from the footsteps of man – except for the sensitive eco-green admirer.
The weird, counter-intuitive thing about the conservationist is that they don’t want people to experience nature except vicariously on TV, and maybe not on TV but lantern-shows in a town hall. Man truly is a virus; whatever he does, wherever he is, he sheds his contagion. But of course he does! Just like animals live skat, ripped up turf and chiseled down trees. The only difference is the scale of Man’s “leftovers”.
The movie “12 Monkeys” is the only solution satisfying the eco-green even if they don’t know it: the eradication of the species known as Homo sapiens.
It is said that our Western world is in a “clash of civilizations” with respect to Islam. The Western world is also in a clash of civilization with the eco-green, except ironically it is with the world that created and now sustains the eco-green.

May 29, 2014 9:38 am

The sriracha factory came within a couple of days of packing up the plant and moving before CA realized its anti-business bizarre antics were being watched by the world. But the mono-agenda crazies just move on to the next target.

May 29, 2014 9:39 am

Well, that settles it once an for all! we all need to move back to the farm and stop having children and stop consuming anything to save the environment! The greens won’t be happy until only non-human creatures walk on Mother Earth except for those few creatures who are Greens and who deserve to be here.

May 29, 2014 9:40 am

The toppgraphy of the Los Angeles basin supports inversion layers in warm weather that inhibit the flow of air out of the basin. The onshore breeze rises over the trapped air bubble rather than displacing it inland.
The original people who lived in Los Angeles, the Tongvas, called the San Fernando Valley the Valley of the Smokes, because the topography of the area captured the smoke from their bonfires and kept it there. That was LONG before internal combustion engines aggravated the problem.

May 29, 2014 9:41 am

Horse-drawn airplanes?

May 29, 2014 9:42 am

They won’t have to worry long as the runways will soon be underwater. So says the dumbest man in Calif. Gov. Brown.

Charles Davis
May 29, 2014 9:46 am

This is good work about LAX and amelioration is probably possible by modifying flight patterns. Furthermore, they probably will do it. Pollution worldwide is a huge issue and causing cancer rates to soar. We are talking millions of deaths annually. If all the global warming $$$ had gone instead to pollution abatement, we might have a better world to show for it.

May 29, 2014 9:49 am

Wait a minute… there’s something to this. I think shutting down LAX, La Guardia, JFK, Midway and O’Hare. would be a great start to “solving” what is a clear crisis. We could divert the traffic to the States that just don’t care about all that terrible pollution like Texas, Kansas, Arizona, Nevada, Montana, West Virginia, etc. And if you really think you need to visit the cities and areas the offending airports previously served, you can rent a bicycle at any of the Airports where the traffic has been redirected. Everybody wins!

May 29, 2014 9:49 am

Hmm, let’s see, in less than 1000 years the world has gone from a population numbering in the millions to one numbering in the billions. The sole means by which this was able to occur, and which governments, especially those of the utopian statist variety, have been eager to control (throttle) was technological innovation in the production, storage, and transport of foodstuffs, and energy production for industrial operations.
As a result, we have the largest, healthiest, wealthiest, best-educated, and longest-lived world population in the history of the world, in spite of political morons like Marx, who opposed (uncontrolled) technological innovation because he believed it would cause the worker to be displaced from his job, and their statist fellow travelers who, in the 20th Century alone, have caused the deaths of over 260,000,000 civilians in their eagerness to transform their societies and retrofit their populations for their idea of paradise.
And this doesn’t even include the more than 100,000,000 people in Africa who lost their lives since the 1970s due to the banning of DDT by environmental utopians, or the approximately 1 billion people lost to the various eugenic/overpopulation factions of the same utopian nutcases since 1950.
If these researchers want to measure true threats to human existence, they should concentrate on the role of oppressive governments in the erosion of human well being and the catastrophic results of technological dirigism arising from their defective political philosophy that threaten the whole system.
The danger isn’t at LAX or in any boardroom of any corporation but in Washington, D.C. and other world capitals. Too bad the researchers are beholden to government largesse and too often conveniently discover exactly what most facilitates the continued existence and encroaching power of these governments over the innovative and productive parts of society.

Curious George
May 29, 2014 9:51 am

Have you ever heard of a PN (Particle Number) criterion before?

Lance Wallace
May 29, 2014 9:51 am

The study shows that LAX is an important source of OUTDOOR ultrafine particles. However, people spend on average 22 h/day indoors. Although outdoor UFP penetrate the home envelope, their concentrations are greatly reduced indoors due to their higher Brownian motion as they pass through the cracks. Only about 25% of the outdoor concentration actually makes it indoors. So unlike the case for fine particles (PM2.5), where outdoor sources account for about half of personal exposure, UFP exposures are primarily indoor-generated, with the main source being cooking, whether on gas or electric stoves does not matter. (In northern Europe, where people use candles a lot, the candles are a source about as strong as cooking.)

May 29, 2014 10:01 am

It’ll be all those celebrities jetting off to save the world.

Joe Public
May 29, 2014 10:02 am

Perhaps the airport should be relocated further from the city.? Maybe to a higher location?
Obviously, someone would need to calculate the benefits, not forgetting to factor-in the added pollution created by all those cars driving further (and higher?) to deliver and collect those thousands of passengers and workers.
Would a local reader pass on my suggestion to the governor?

Lance Wallace
May 29, 2014 10:04 am

Curious G:
A PN (particle number) criterion has been (or soon will be) established for diesel engines. One reason is that initial attempts to reduce diesel particulate pollution concentrated on reducing particle mass (the usual measure). These attempts succeeded in reducing mass emissions but increased ultrafine particles, which have negligible mass but overwhelming numbers. Since both UFP and PM2.5 have health implications, (a study in Erfurt, Germany showed mortality from cardiorespiratory disease was correlated with UFP but not PM2.5) it has been felt necessary to establish this second criterion on particle number (PN) as well as mass (PM).

May 29, 2014 10:07 am

I thought a lot of their pollution was coming from the cargo ships?
I read on NRDC that they have converted many of the docks to provide shore power, allowing the ships to turn off their engines while docked. You still have pollution being generated upwind while underway into and out of the ports.

Joel O'Bryan
May 29, 2014 10:12 am

Sounds to me like California needs a high speed Train….from Fresno to Bakersfield to help reduce those PN’s.

May 29, 2014 10:15 am

From the description of their experimental methods, it would seem that they have not proven that the additional pollution comes from airplanes. LAX is a huge parking lot, with large numbers of vehicles going slowly, stopping and starting, or just plain idling; all of which are non-optimum for car efficiency / emissions. From the sheer number of cars/trucks/busses, my guess is the emissions from aircraft are dwarfed by the cars.

May 29, 2014 10:19 am

@Kaboom – that is one way to depopulate the state. And the funny thing is – the liberal California democrats would support it!

May 29, 2014 10:20 am

@ DickF –
I’m still waiting for that special investigative report on whether the sun will, indeed, rise tomorrow.

May 29, 2014 10:20 am

So the world is not a perfect place.
[Now] confirmed by peer reviewed science.

May 29, 2014 10:20 am

“now”…now confirmed by peer reviewed science.

Barbara Skolaut
May 29, 2014 10:24 am

“I think shutting down LAX, La Guardia, JFK, Midway and O’Hare. would be a great start to “solving” what is a clear crisis.”
Dulles and Reagan first!

May 29, 2014 10:44 am

Think food rationing. A lot of produce flies into and out of LAX and for years the poverty development people have been promoting the consumption of locally grown food claiming that the transport of it contributes to global warming.

Mike Bromley the Kurd
May 29, 2014 11:15 am

Perhaps to inject a little sensibility here, this is about actual pollution….something that does have serious implications. While air quality in TinselTown has improved a hundredfold since the smog-laced Sixties, some stuff remains. Moreover there should be no equivocation between pollution and CO2, which also remains. The question is, is how ultimately serious is JetA exhaust as an overall cost/benefit circumstance? Probably not very.

May 29, 2014 11:25 am

I would be more interested in results from autopsy reports of folks living near LAX or other major airports.

May 29, 2014 11:48 am

Yet the California Air resources Board is more concerned about putting restrictions on my lawnmower.

Don Newkirk
May 29, 2014 12:12 pm

It seems to me that they found some data on particulates, but the ran an alarmist piece bent on connecting non-existent points, in that they forgot to do the epidemiological study to determine whether the particulates represent an unhandled new problem, or merely interesting facts.

Curious George
May 29, 2014 12:13 pm

Lance – thanks. It looks like the authors applied their diesel expertise to airplanes.
Barbara – it may be a little indirect, but how about shutting down Hollywood first?

May 29, 2014 12:14 pm

Lance Wallace – good point, the ultrafines also have an understood possible metabolic pathway but I don’t know if the epidemialogical data is there? Also Lance – maybe current Euro controls don’t get ultrafines but I thought DPFs were effective? (so, post-2007 onroad USA diesels and post-2010 offroad?)
Finally Bill – I agree, i’ve seen a study before about the large #s of diesel equipment at airports…

May 29, 2014 12:15 pm

Don Newkirk – good point, though that would be someone else’s study typically. The studies have been done (and criticized) for PM2.5, but not sure about ultrafines.

May 29, 2014 12:48 pm

tadchem says:
May 29, 2014 at 9:41 am
Horse-drawn airplanes?
Ugh! That makes me think of a new kind of pollution, that could be much worse.

May 29, 2014 1:11 pm

I’ve never understood why the Greens et al do not campaign vociferously against air travel. Couldn’t be because of the foreign junkets of course…

May 29, 2014 1:40 pm

Epidemiological studies are the bane of our existence. The public lives their lives in fear of weak correlations that researchers grasping for grant money or to puff up their egos inflate to immense and unproven proportions.
An epidemiological (or observational or cohort) study should only be used to isolate items for further study and never attempt to prove cause and effect. Just too many confounders are possible without controls.

May 29, 2014 2:01 pm

People may want to read Matt Briggs’ takes on the epidemiological studies that purport to show health harms from airborne particulates.

Just an engineer
May 29, 2014 2:12 pm

tadchem says:
May 29, 2014 at 9:41 am
Horse-drawn airplanes?
The correct answer is, “Unicorn-drawn airplanes”!

May 29, 2014 2:49 pm

You can pretend you’re a celebrity by using “airport transportation Bakersfield ca“. I think that’s as close as some of us are going to get!

May 29, 2014 3:05 pm

Shut it down.
And the harbor, sail boats ONLY.
And the trains.
And the roads.
These morons need to experience what they want.

May 29, 2014 3:20 pm

They won’t be happy till those non-essential to running their utopian world, are back in caves.
So, here we are.

May 29, 2014 3:53 pm

I think that given that “Scott Fruin, D.Env. P.E., Neelakshi Hudda and colleagues” have outright stated that they realise the damage they are doing, that everyone who lives within 10 miles downwind of any airport file suit against them if they ever get on an airplane again. I’m sure that damages in the range of 10,000,000USD per victim are appropriate. If they claim to not be guilty, or plead ignorance, one need only to point to this study.

May 29, 2014 4:54 pm

Well, most arrivals do set you up on final just south of downtown, but the departures generally keep you several miles out to sea until you climb through 8 or 10,000.

May 29, 2014 4:55 pm

Must be bodies laying everywhere. Wait . . . what?

Martin Katchen
May 29, 2014 4:56 pm

Interesting how the study totally seems to ignore the very real issue of lead pollution from gasoline powered piston airplaines from general aviation airports. Read Mother Jones “Lead : the Criminal Element”. Lead has been conclusively linked to violence (and don’t anyone comment until they have read the article!) by causing learning disabilities and ADHD at relatively low levels. The real epidemiological proof of this thesis was been found in retrospect as crime rates declined first in areas which banned leaded gasoline first with areas banning leaded gasoline later experiencing a drop a few years after those cities and states that banned leaded gas sooner. The problem is that aviation gas is the one form of gasoline that still uses lead tetraethyl oestensibly for safety reasons, making the flight paths for GENERAL aviation airports islands of lead posoining for children unfortunate enough to grow up under them. (Again, just google and read the article, folks. It dosen’t come out of a particularly Green agenda, but out of the kind of serendipitous discovery that REAL science is made of. In fact it throws other Green causes such as anti-vaccination into a cocked tin-foil hat.)
If this study is focusing on L.A.s major jet airports, there may be a not so hidden agenda at work here. California’s high speed rail project runs right by Palmdale, which was going to be the site for the new LAS until the Sierra Club persuaded LA to abandon the project in I believe 1973, in favoour of shoehorning more jets into LAX. A couple years ago, the neighbourhoods around LAX (particularly Westchester and North Inglewood, which have become cool to live in) were successful in putting a cap on passengers per year for LAX. What this means is that a) the only way for LAX to expand more oucrative flights to places like Asia is to cancel the large number of short haul flights to San Francisco and b) if high speed rail makes it possible to reach Palmdale from Downtown LA and UCLA and Hollywood in 15 minutes, LAX can be closed in favour of an international airport (and perhaps if Elon Musk and Bert Rutan have their way, a spacepor to Earth orbit) at Palmdale extending to Bakersfield, Fresno and SF ( probably the East Bay, the Peninsula envies Marin’s County’s splendid isolation too much to tolerate something as tawdry as high speed rail). With high speed rail under political fire, maybe that is the real reason this study is coming out now of all times.

May 29, 2014 5:08 pm
May 29, 2014 5:35 pm

Gamecock, if you somehow found yourself on the ground between JETSA and ARBIE (see chart above) you’d be right. That’s a pretty rough neighborhood. 😉

Mark Luhman
May 29, 2014 5:38 pm

“Bob Johnston says:
Epidemiological studies are the bane of our existence. The public lives their lives in fear of weak correlations that researchers grasping for grant money or to puff up their egos inflate to immense and unproven proportions”
This we all are going to die from small particles, is an huge pile of adult bovine fecal matter. Smoking one cigarette you take in at least 100 to 150 days of PM particles. To take in as much as some who smokes on year you would have to live over 1500 years. Yet the studies of cigarette smokers show that the chances of a smoker dying from PM in the first 10 years is basically nil. Yet the grants roll on for these types of Epidemiological studies. I you really want to know the danger you only have to study smokers, of course if they did they would not get the answers they want.

May 29, 2014 5:46 pm

It’s ‘more worser’ than we thought.

May 29, 2014 5:54 pm

It is busy out there. But not quite as busy as the headline image would imply….

William C. Rostron
May 29, 2014 8:03 pm

Martin Katchen,
Leaded fuel is only used in piston-powered general aviation aircraft. There is no tetra-ethyl lead in jet fuel.

Mike T
May 29, 2014 9:12 pm

This would not be news to anyone who has lived near airports, especially those in or near major cities, or spent much of their working lives AT airports, as I have.

May 29, 2014 9:24 pm

bonanzapilot says:
May 29, 2014 at 5:08 pm
Typical Final Approach
Went to your interesting link, it wouldn’t let me back out though !!
Finally found my way back home 🙂

John F. Hultquist
May 29, 2014 10:27 pm

Martin Katchen says:
May 29, 2014 at 4:56 pm
“California’s high speed rail project runs right by Palmdale …

As does the San Andreas Fault Zone.
Seems like a great place to put an internationaal airport.

James Bull
May 30, 2014 12:36 am

They won’t have to worry for too long as it is all going to be flooded when the Antarctic melts.
As for
tadchem says:
May 29, 2014 at 9:41 am
Horse-drawn airplanes?
It reminds me of “Wings over Dagenham” by the Goons in which one of the characters bemoans the demise of the horse drawn Zeppelin!
James Bull

Charles Nelson
May 30, 2014 2:09 am

In one of those eerie co-incidences I’ve heard just recently heard several people relate tales that we are in fact being ‘sprayed’ with ‘chemical’ from high altitude ‘secret’ ‘government’ planes!

May 30, 2014 5:11 am

Why don’t they go after commercial shipping? That produces twice as much in emissions as air traffic and is set to almost double in the next 20 years.
Let’s see how interested they are when their bananas and Japanese TV’s can’t turn up at the docks any longer.

May 30, 2014 7:14 am

Martin Katchen says:
May 29, 2014 at 4:56 pm
The problem is that aviation gas is the one form of gasoline that still uses lead tetraethyl oestensibly for safety reasons, making the flight paths for GENERAL aviation airports islands of lead posoining for children unfortunate enough to grow up under them.

May 30, 2014 10:43 am

WUWT says, “Then They Came for the Airplanes”
WUWT is right, the logical conclusion is that air travel will become regulated and then banned by federal agencies with the power to regulate PM (particulate matter, whether 2.5 or not). This would not end all air traffic, it would simply outlaw air travel for most people. In other words, flying would become a class privilege, for people in government and those made wealthy enough by government. But if it had been up to government, we would not have been the first country to fly, nor would we enjoy the prosperity which allows all of us to enjoy free travel all over the world.
A little history – Uncle Sam Can’t Count: A History of Failed Government Investments, from Beaver Pelts to Green Energy.
We have all heard of the Wright brothers who developed their first gliders in Kitty Hawk, NC, and later added an engine made with parts from their bicycle repair shop. But I had not heard of the government subsidy to develop the air plane. The government picked a man who had written books about flight, had many degrees, and who worked for the Smithsonian. Listen to the entertaining and enlightening story of flight as developed by the Wright bros from @16:67 to roughly 39 minutes:
Please listen and enjoy,

May 30, 2014 10:46 am

Correction: Story of Langley government flight subsidy vs. Wright Brothers, 16:47 – 39:00.

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