Following up on yesterdays post, I wanted to point to a presentation given by University of Utah Research Associate Kerry Kelly that is available
here and discusses the significant impact of wood burning on pollution in the Salt Lake Valley. The talk is based on
Kelly et al. (2013), published in the
Journal of the Air and Waste Management Association.
Here are the key points:
1. Wood smoke (and possibly cooking smoke) is likely the largest
direct contributor (i.e., emitted from a source) to PM2.5 on winter days with PM2.5 > 20 ug/m3. Note that our PM2.5 comes from these direct emissions and from chemical reactions involving other gases generated by combustion (such as nitrogen oxide). The latter are typically referred to as secondary PM2.5.
2. Wood burning emissions are highly variable depending on their design, operations, and fuel, but they are far filthier than heating with natural gas.
The bottom line is that you can do some serious air quality damage when you burn wood in a stove or fireplace. Although there is no silver bullet when it comes to fixing our air quality challenges, reducing or eliminating wood burning in the Salt Lake Valley (and possibly elsewhere since there is some exchange of air between the counties) represents low-hanging fruit that can be plucked to improve air quality during wintertime inversions.
So this seems to be the latest wave of "we need to do this or die" movement. I am just wondering why it is now and not earlier that the issue with wood burning has not been so pushed on to the public, its not like more people heat there homes with wood now then they did 20 or 50 yrs ago. Another thought, Could this be evidence that previous time periods of global warming were indeed caused by "wood" burning fires (forest fires) and not SUV's with little Mormon children in them. Alright rant over, great blog.
ReplyDeletetcruicks provides some discussion of why this hasn't been brought up previously. In addition, if you look at the talk that is referenced, they mention that the wood burning contribution has previously been underestimated.
DeleteThat being said, I need to emphasize that this isn't going to magically fix the inversion. I see it as simply a low pain option to give us some modest reductions in emission. I leave the question of whether or not to ban wood burning altogether or attack this with an educational/voluntary approach to others.
I'll add some info and comment to the previous discussion. There are less than 200 homes approved for sole source wood/coal burning in the County (I think County). That's not a lot, but really it ought to be zero. My comment on wood burners is that it is hard to enforce a wood burning rule whether we ban it completely or periodically. The staff at DAQ cant patrol the whole Front. It would seem that some kind of Health Department and police department cooperative could be helpful and perhaps that has happened in the last couple of years but I do not know. I dont think the program at present carries the weight or seriousness with it to really affect a whole lot of change of behavior.
ReplyDeleteI ride my bike around a lot and if you see burning on a red day, call air quality and they will send a car out. They issue a warning the first time. I have a neighbor here just adjacent to the U and he burns coal every chance he gets, presumably just to foul the air, for he has a $400k home. Sick stuff. We need stricter no-burn rules.
DeleteThere needs to be an attitude shift here, as well. When we got our crumbling chimney* capped, and a proper flue installed, then sealed it (for post-apocalypitc use only), we got an avalanche of "Oh! You'll want to burn it sometimes! It smells so nice!" I grew up with a coal furnace, I never want to breathe in that much dust again.
Delete*Newly bought old house.
Anonymous, I think the issue is coming up, at present, because there are not other PM2.5 reduction levers that dont come with a huge price tag right now. The State really has very few options especially in this political climate. The wood burning has always been there, to some extent, but now other contributors have been reduced so it is coming into focus as a "no" cost option to gain some reduction in PM when every little bit counts.
ReplyDeleteOn cars, driving less, mass transit, biking etc all help, but the biggest change will be when the auto fleet flips over and all the vehicles are older than 2005 (newer cars are much much cleaner). This really is a wait it out game because you could remove all the older cars but that would be quite a thing.
Great to see some discussion here amongst the comments!
ReplyDeleteJust out of curiosity, are restaurants allowed to have wood-burning pizza ovens? What is the rule? Do we not have these simply because Americans make lame pizza?
ReplyDeleteOf course -- cars cars cars are the main game. I hope (optimistic day here) that in the next few years the SLC power 1,000 comes to its senses and makes the city a leader in pointing the way toward new urban models. In the meantime, could a cop just once give someone an idling citation during a bad air day? Could we not at least ask the local TV stations to remind people not to idle?
I think an important thing to remember here goes back to Jim's first point above - that Kerry's estimate (via source apportionment) for woodsmoke was 38 percent of the Primary PM. The primary particulate (based on lab speciation of Hawthorne filters for high PM 2.5 days) makes up less that 20 percent of the total PM mass. It's all about the secondary particulate, mostly ammonium nitrate. So the real contribution of woodsmoke to what we breath is more like 7-8 percent based on Kerry's approach. And that includes restaurant char cooking which could not be distinguished. UDAQ's estimate (see presentation referenced by Jim above) that woodsmoke contributes .20 X .16 ~ 3 percent is not all that different. Sure we should take all the easy reductions we can but let's also remember the real emissions are coming from the vehicle fleet and industrial sources.
ReplyDeleteBTW - UDAQ now calls for voluntary woodburning restrictions at 15 ug/m3 and mandatory restrictions at 24 ug/m3.
What are the views on the logs that are presumably cleaner - like the coffee ground logs?
ReplyDeletehttp://www.pinemountainbrands.com/pages/java_log___firelogs/20.php
Fact is, increasing population = more cars. More cars = more pollution. Since you can't limit birth control like China, the answer is to move out of the valley (Park City)...or find another metro city to live in. The end.
ReplyDeleteThat just confirms an old paradigm. We are trying to consciously move away from that mantra because soon enough nobody will want to live here. Is improvement in the face of growth not a worthy endeavor?
DeleteYour comment seems defensive, which i don't understand. And it is by no means the definitive end of the story
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ReplyDeleteI answered my initial questions by looking at the slides and the paper. This raised additional questions: There is no attribution (or discussion of) coal burning in the paper, and only a brief mention that some of the signature of wood burning could be due to cooking. Are these sources significant?
ReplyDeleteSecond, I was under the assumption that all particulates were not created equal. Do they fall out (or attract water) at different rates? (I would again assume that a particulate that hangs around longer is more dangerous.) If my assumption is correct, which source is most dangerous? (This seems to be a very important question before making policy.)
More! Feed me more! (I love learning.) ;)
I know that the top of my car collects a film of soot during condensation, or deposition, of moisture at night during the bad smog episodes. So I think maybe it is actually cleaning the air (OK only teasing, since I do drive it). But this does show that some of the particulates either precipitate out on their own, or get cleaned out of the air due to moisture processes. Do we have any idea what the half-life of a given type of particle is, and how this may vary with different weather conditions? I suspect that high humidity, for example (and especially dense fog of the natural variety) may help to remove certain types of particulates. Is there a way to test these things in a lab? Maybe this could even contribute to some technology to help clean the air.
DeleteThey are trying to ban wood burning in Fairbanks, AK as well. During times of bitter cold arctic outbreaks when the temp drops to -50F, a super inversion usually sets up where the temp at 1000 ft AGL is usually around -20 - 0F. As you can imagine this traps everything at the surface leading to Fairbanks having the worst air quality in the country, rivaling cities in China. The problem is, most people up there heat their homes through wood burning as natural gas is extremely expensive and most cannot afford it. To ban wood burning, at least up there, would put people's lives in danger as those temperatures are lethal. I agree that, at least in SLC, wood burning is not necessary to survive.
ReplyDelete