March 03, 2014

Are Coal Trains Degrading the Air We Breathe? The Answer is Yes.

During the past week, a paper describing the air quality effects of coal trains lumbering through the Pacific Northwest was accepted for publication and finally I can tell you about it.

This work was completed by Professor Dan Jaffe of the University of Washington in Bothell and several UW students, and relates the results of an extended observational study above the tracks in north Seattle and in the Columbia Gorge.

Let me begin by thanking many of you for helping to make this research possible.  Dr. Jaffe and I had talked about determining what was coming off the coal trains, using modern instrumentation, for a while and we even did a test run on the bridge at Richmond Beach park (I really enjoyed the excitement of waiting for coal trains and then watching the particle monitors as the train  passed underneath).  But the project required more equipment and student help to do it right, which meant a need for funding.

This research was a too controversial for State agencies and I suggested to Dr. Jaffe that he try a new funding source:  crowdfunding over the web.  Roughly a year ago I asked you to assist with the funding, and a number of you stepped up to the challenge and played a major role in funding this important research. Thank you.

Let me summarize what this research found in Seattle...and so you don't die of suspense...the answer is yes. Coal trains clearly degrade air quality.

The air quality sensors were placed near the train tracks in the Blue Ridge neighborhood on the patio of a volunteer homeowner.  The location was kept secret for a number of reasons, including fears that some folks might view the sensors as a threat and destroy them.

Dr. Jaffe's students placed a number of air quality sensors at that location, allowing the measurement of particle sizes and CO2 levels, as well as an automated videocam that facilitated the determination of the type of train.   There were two main types of potential pollutants from the train:  small particles from the diesel exhaust and coal dust.

Let me show you what happened when a coal train went by during the morning of August 13, 2013.  First, there is spike in the amount of CO2 produced by the train's diesel engines.  The plot also shows TSP, the total amount of particulate matter in a cubic meter of air, and PM1, which is the mass of particles in a sample smaller than 1 micron (millionth of a meter).  TSP includes the mass of particles of all sizes and the difference between TSP and PM1 is a measure of the amount of large particles--like coal dust.

Note this is a minor peak in TSP with the engine, but a minute or two later there was a HUGE sustained peak that was probably due to coal dust.  PM1 also went up with the engine and in its wake, and the difference between TSP and PM1 jumped big time--a clear indicator of large particles (i.e., coal dust). Keep in mind, these long coal trains can take several minutes to pass a point.

The example above is not unique and one quickly draws the conclusion that folks near coal train tracks are exposed to noxious diesel exhaust AND coal dust.  To get an idea of how serious this issue is, here is a comparison of daily average PM2.5 levels (a measure of the concentration of particles less than 2.5 microns) over entire month last summer at Blue Ridge (near the train tracks), in the Duwamish industrial zone, Beacon Hill in Seattle, and suburban Lynnwood.  Keep in mind the PM2.5 particles are nasty little creatures than can get deep in your lungs, worsening asthma and heart disease.

Wow!.  That beautiful view home in Blue Ridge, with an expensive view of the Sound, has air as bad as the industrial Duwamish.  Most of the Blue Ridge pollution was from diesel engines from coal and non-coal trains.  Beacon Hill is better and Lynnwood is like breath of fresh air.

Dr.Jaffe is planning another field experiment in Seattle and the Columbia Gorge (where winds and "fresher" coal would cause the coal dust concentrations to be more serious).

Coal trains are bad news from so many viewpoints:

1.  The diesel effluent greatly degrades the air quality in neighborhoods around the tracks.
2.  There is clearly coal dust coming off the trains, even when it is not visually apparent (like north Seattle).
3.  The trains cause substantial increases in traffic jams, worsening pollution from cars, and impacting public safety and the local economy.
4.  The planned coal on these trains would substantially contribute to CO2 increases in the atmosphere that will change the climate of our planet.
5.  A significant portion of the  pollution from the burning of coal in Asia will make its way back to the Northwest, further degrading our air quality.

What's not to like?

Coal trains are environmental and economic disasters that are not worth the handful of train and terminal jobs they would produce.  Wherever you are on the political spectrum, you should be against these trains.

Addendum:  A lot of folks ask why the coal trains are not covered.  When I asked this question, I was told it was because of fear of explosion of the coal dust, but perhaps one of you knows the story better. 


  1. Putting aside all other considerations, it amazes me that coal cars can't have retractable covers.

    Coal cars, like those that carry other bulk materials like sulphur, are rotated in situ in dumpers that use water sprays to keep down the dust. Why can't a retractable cover be engineered that retracts to the side as the car dumps?

  2. Never mind the chemical that they wash the coal with that poisons the groundwater... have one look at West Virginia!

    I love trains but NOT coal trains. This is really valuable research and I hope it ends that particular discussion.

  3. And, astonishingly, they fill they about the top of the car sides, so the coal is swept off in the wind. I see these coal trains rumbling through Golden Gardens every day now. Why do these corporations have the right to degrade our air quality and health?

  4. You are comparing roughly 4-minute highs to a 24-hr average? Do you have a 24-hr average of the site where the coal train passed?

    Seems like for an apples to apples comparison we'd need equal averaging times. Also comparison of days when no coal trains but other non-coal trains passed.

  5. Figure 6 shows that the effect is quite transient, lasting only 3 minutes. Coal trains alone surely can't explain the daily average air quality. Nevertheless, is anyone surprised that air quality is degraded 25 m from a double track railroad? As for that "beautiful view home ... with an expensive view" (which was no doubt built after the railroad), I'm sure this paper will serve to lower its value!

  6. So what can we do? Who can we start petitioning to get these trains stopped or at least made safer?

  7. Can you tell us when this will come out in the on-line journal? It is not in Volume 5 issue 1....

  8. What are the OSHA exposure limits for these? The peaks look high, but last about 2 minutes before coming right back to normal. Looks bad - and probably is - but you need to provide a bit more context for this. In what other ways does elevated TPM exposure happen, and for how long? What are the relevant legal limits?

  9. Coal much worse bad when it is burned, look at the pollution in China with air pollution as 10x World Health Organization standards. A large portion of the pollution is due to coal. Then there is the global warming and the ocean acidification now killing the scallops off our coast.

  10. You do not need to go as far as China. The external or social costs of burning thermal coal to generate electricity are much more than the retail value of the electricity. Where is the Environmental Justice? People downwind of the coal fired generating plants pay a very significant cost for the low cost convenience of others. Is this the american way?

  11. That's some amazing good work you-all are doing! Providing some non-ignorable solid data which the Corps-of-Engineers will have to ...ignore.

  12. I'm sorry, but some of these conclusions are pretty shoddy. For example:

    "1. The diesel effluent greatly degrades the air quality in neighborhoods around the tracks.

    3. The trains cause substantial increases in traffic jams, worsening pollution from cars, and impacting public safety and the local economy."

    The same is true of ANY large train, coal or not. Do we ban *all* trains just because cars get stuck waiting for them and because the train engines produce exhaust? I think not.

    The following conclusions also are almost certainly wrong:

    "4. The planned coal on these trains would substantially contribute to CO2 increases in the atmosphere that will change the climate of our planet.
    5. A significant portion of the pollution from the burning of coal in Asia will make its way back to the Northwest, further degrading our air quality."

    This presumes that the Chinese, who are buying and burning most of this coal, will not be able to get the same amount of coal elsewhere if we did not ship coal to them. This is almost certainly wrong. There are plenty of other coal mines in Australia, Russia, Indonesia and elsewhere who will be more than happy to sell the Chinese their coal if we do not. Ceasing to ship our coal to them will make no difference in the amount of coal they burn; the only difference it will make is change where the Chinese get their coal from, and thus the same amount of pollutants will blow over to the NW.

    Shoddy, shoddy conclusions!

  13. BNSF says they lose about 500lbs of dust and loose coal /per car/. These are roughly 100 ton cars so that's about 1/400th of the load. The majority of this is lost near where the car is loaded, before the load has had a chance to settle. Other sources say it's as little as 225 lbs or as much as a ton per car. It probably depends a lot on the weather.

    Some loaders are covering the coal with a "surfactant" (it's non-toxic: chemically similar to the paste schoolkids use), which experiments indicate cut the dust loss about 80%. Several railroads are experimenting with covers, which will probably work as well or better. Since most of these operations load/unload 500 cars a day, it has to be pretty non-intrusive to operate.

    I'm skeptical of whether the larger question can be resolved by attacking the small problems around the edges. should we be helping other countries emit gigantic amounts of fossil CO2 into the atmosphere for the benefit of a few wealthy businesses, and negligible or negative benefit to the average American?

  14. Much as I share your sentiments, Cliff (and adamantly oppose the proposed terminal here in Whatcom County), I have to agree that your conclusions here beg obvious questions and are applicable whether or not coal is part of the equation. Were stats compiled, by way of comparison, when trains passed that didn't carry coal?

  15. Disappointed, Cliff. I think you are drawing conclusions based on VERY MINIMAL studies, here.

  16. I would say that the reason coal cars are not covered is probably very simple: 1) it costs less money that way, and 2) it doesn't hurt coal to get rained on.

  17. Which came first, the beautiful house with the stunning view or the railroad? Can I build a fancy housemate then ask for the railroad to go away?

    I want to speed the transition away from fossil fuel, but do the owners of fancy houses along the tracks care about the fossil fuels or are they just lining up with the anti coal forces to fight the increased rail traffic along their waterfront property?

    And I'm not that impressed with the study. I'd look for other reasons to object to burning coal.

  18. Don't like coal? Stop using electricity! It's a simple equation.

    As it turns out, the coal dust, particularly at the mine end (mostly the Powder River Basin in Wyo), makes the RR's lives miserable, too.

    It fouls the ballast meaning that instead of nice, clean, rock ballast that allows water to drain from the track structure properly it gets muddy from the coal (and other) dust. Then it develops what you might think of as potholes that cause the track to start to move around.

    The railways (who don't own the cars coal is shipped in in most cases) want the shippers to do something about the dust (spraying a coating seems to be solution most often heard) and the shippers will have none of it.

  19. So, doc, you accept findings that coal cars pollute the air we breathe, but dispute that C02 emission settle in the ocean causing it to become more acidic and kill shellfish? Like the 10m worth of scallops last week on Vancouver Island. Cor, really.

  20. I would assume that the closer to the coal's point of origin you are the worse the particle pollution will be.

  21. the coal dust furor misses the point. the problem is with increased CO2 from burning all the well as mercury etc released into the atmosphere.

    focusing on the coal dust will allow (1) others to dismiss the concerns by calling it nimbyism (2) the issue to be ignored once train companies find a way to reduce coal dust.

    and i am not even convinced yet by the evidence collected by Dr Jaffe -- at least that presented here. as others have pointed out, there is no info on what sort of pollutant levels are measured during passage of non-coal trains. also, how do these levels depend on train velocity and/or weight?

    i live a block from the train tracks in seattle and i watch lots of trains go by. i can think of many instances where i saw dust get kicked up from the ground by passing trains. i can think of the times i got caught in a plume of diesel exhaust. i can not think of a time i saw coal dust blowing off a coal car, except in extreme winds (actually, that was in the Gorge, not in seattle)...

    that people living near the tracks are exposed to diesel exhaust, and that this is bad, is not a novel finding and not worthy of publication...Jaffe should not rely too heavily on this being a 'key finding'...his study needs to be honest regarding the 'coal dust.'

    then lets move on and focus on the actual combustion of those train loads of coal, the real problem...

  22. Cliff, this study is VERY narrow. No data from other trains passing? The conclusions are biased as the study is biased as the studiers are biased. That's NOT good science. If it was, sensors would be placed next to interstate highways, major roads and alongside the runways at SEA/TAC airport. Yes, you folks complaining about coal dust in your town, (dust of which actually blew out in Wyoming if not held by surfactant) and emissions, may find you are the ones actually polluting the planet, by driving your cars and riding buses and traveling by air. Don't forget to stop buying the Chinese products riding in those containers on many of the other trains. I suspect those other sensors that should have been placed would find high levels of emissions and.... wait for it.... dust. From dirt. Kicked up by wheels and wind. Trains have wheels and make wind too.

  23. Good thing your a scientist, otherwise someone my question your impariality.

  24. Well, I do not have a firm opinion yet based on this data. For some reason I keep thinking about the dust storms in Phoenix (and those that occur elsewhere) wondering how that compares. Then there are those Santa Ana winds in LA I had to live with. Not to mention the smog. It is a wonder how any of us survive. There must be body mechanisms to combat all of this. I think we would need medical data from residents to also parallel this data before I would worry.

  25. After reading through the study one thing kept occurring to me, exemplified by this quote "Though we did not collect PM samples for chemical 
    analysis,  it seems  highly  likely  that  the relative  contribution  of 
    larger particles due to the total PM mass consist of aerosolized coal dust from the uncovered coal trains."

    Why did they not analyze the particles and take care of this giant hole in the study? Not that I necessarily disagree with the statement, but such an oversight is just plain sad, for lack of a better word.

  26. Hey Cliff, I'm trying to understand Figure 6... it appears this train began to pass the monitoring site at 9:56. If I look at the time-course of the measured parameters, it looks like the train had passed (or at least the measurements) returned to baseline at 9:59. Does this make sense? Was it only a 3 minute train (I live near the tracks in the same area and they seem to last much longer than 3 minutes).

    What does this "trace" look like for a non-coal train. Does this trace depend on the number of locomotives? I see trains with 1, 2, 3 or 4 diesel engines. It would be great to see some sort of control to assess how much of this trace is from the engines vs the cargo.

    Alas, I don't have access to the original article so I can't answer these questions myself.

    Thanks in advance... A fellow scientist.

  27. Cliff,

    Please measure the emissions every time you fire up your car. On to the airport. Please measure the emissions from the aircraft as it takes off...on the way to a conference...of meteorologists.

    And back.

    Mainline rail is the most efficient way to ship commodities via land. By far. The new locomotives are far less polluting than trucks for moving a similar amount of goods of any type. And are mandated to get cleaner.

    It is hard for me to believe that you, of all people, are attacking rail transportation by setting up an emissions monitor on a HUGE house in North Seattle adjacent to railroad tracks.

  28. Thanks for your excellent analysis Cliff.

    It's a good thing the downtown ferris wheel and proposed gondola offer riders airtight compartments as they spin and hover in the dust of the passing coal trains.

    Where is our country's leadership on climate change? At a time when we should be cutting back on our use of fossil fuels, we're shipping ever increasing amounts of coal to China and will probably build the Keystone pipeline.

  29. Just to seal the deal, I would like to see data for all trains, not just the coal trains. I suspect that coal trains put a lot more fine particulate matter (PM) in the air as they trundle by, but wouldn't it be truly amazing if *all* trains caused entrainment of PM, simply by their passing?

  30. More data from Australia on the impact of coal trains:

  31. The only reason this is getting attention is that for once it affects rich people, too. Usually we just push the pollution off into poor neighborhoods, where no one cares.

  32. Driving your car degrades the air. What of it. How about a study next to a freeway.

  33. I live next to the railway track in Canada (20 m). CP operates the freight and it is a main line running 17-22 trains per 24 hour period but I believe no coal. Obviously, I am concerned over study. The diesel is worse than the coal b/c of the PM1 being breathed in at least in terms of the air pollution.

    I was trying to put locomotives in the context of trucks not in terms of efficiency on a ton mile per gallon basis but in terms of the amount of spent fuel that gets emitted in front of my house. From the numbers I have seen it is somewhere between having 25 to 100 trucks per locomotive go by which is very significant it would seem. Can someone confirm?

    I bought a Dylos DC1100 as I was more concerned with air quality inside my house since I take my kids far away from the tracks when playing outside. Just received it today and even though I realize it doesn't track the majority of diesel particulate since 90 percent is less than PM1 I was still looking for the spike when the train passed my house which I figured would be from the train and diesel. No spike was detected so far for two trains having passed. Am I missing something? Still concerned over diesel nano and being way too close to a massive source of diesel emissions (I wouldn't be so concerned at a 100m).

    Want to move and not be close to a highway, track or industry but that is becoming increasingly hard to do on any kind of budget.


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