Car exhaust filters fail to clean up ‘ultrafine’ air pollution
studyfinds.org
studyfinds.org
ICE emissions will be irrelevant in 10 years when they're all but banned anyway, and rubber tyres will still be the only way to drive on the road. In fact it'll be way worse with the average EV being heavier and emitting more due to more tyre wear.
https://www.baaqmd.gov/~/media/files/planning-and-research/p...
So vehicle exhaust is 5% of fine particulate matter in the Bay Area, whereas road dust, tire, and brake emissions are 20%. (Where’s the breakdown between brake dust and tire dust? EVs and even hybrids can substantially reduce brake dust. Heck, an eddy current brake could too, if anyone cared to build one. Might be bad for unsprung weight.)
And commercial cooking is 8%, it I suspect this massively understates the problem, since commercial cooking can easily concentrate its emissions right where large numbers of people are walking around.
But here’s the hilarious commercial cooking regulation:
https://www.baaqmd.gov/~/media/dotgov/files/rules/reg-6-rule...
Read the second paragraph: it applies only to charbroilers and only in restaurants that buy 500 or 1000 lbs of beef per week. That fancy Greek restaurant that smokes up three square blocks of a fancy downtown, but it’s all lamb and fish? No emission controls. That little neighborhood place making tasty bento boxes with pork, and probably less than 500lbs anyway? No emission controls. That portable smoked turkey place at lots of county fairs? (Those are IMO horrible to be around.). No regulation.
And let’s not even mention the single biggest source: residential wood combustion at 12%. It’s politically hard to address, but residential wood combustion serves almost no economic purpose and could come very close to stopping without harming people or the economy. Almost everyone already has a perfectly fine non-wood-fired heater, and a narrow exception would be fine.
And yet BAAQMD is willing to ban the sales of gas fired water heaters in a few years, never mind all the existing buildings with tankless heaters in a place where a heat pump retrofit is impractical. And also never mind that we already have gas fired water heaters with quite low NOx emissions and essentially zero particulate emissions.
It’s a lot cheaper than the alternatives. And a lot more resilient in areas with unreliable power.
Really? The efficiency is very low heating a house with wood unless you use it to warm water which is distributing the heat to radiators (and for heating warm water to the showers). Almost no-one who burns wood has this, people just have a chimney in the living room.
And how do you feed the wood into the burner? Waste 10 minutes every hour, 24/7?
You might not be aware but ones that burn the wood twice (even three times) are now common and in fact are law in many places. So they're MUCH more efficient, and drastically reduce the particulates coming out the stove pipe. Another benefit is they only need to be fed once every 24-48 hours (depending on what heat you set the thermostat, what size stove you have, how well insulated your house is and what temperature it is outside.)
Wood stoves are a necessity.
Nothing good will come of trying to heat your house with a wood-burning fireplace. They’re pretty, they’re fun, they crackle nicely, they combust wood very poorly, and they send almost all the heat right out the chimney. And, if they work correctly, lots of air comes out the chimney for the ride (keeping the combustion products out of the house), so a lot of makeup air comes in from outside, cooling your house.
If you want to heat your house by burning something, you want to capture as much of the heat of combustion as practical (preferably the higher heating value, which condensing boilers and furnaces can do, but the lower heating value is a good start), and you want to minimize the degree to which operating the heater forces you to replace conditioned air in the house with unconditioned outside air. A fireplace fails at this.
On an unrelated note, how did they come up with these numbers for percentage contribution? It seems quite difficult to attribute cause outside of a controlled laboratory setting.
And the real issue isnt even the rubber but all the random chemical additives in that rubber. Some basic study and perhaps modification could also reduce impacts.
Dream on. Germany and EU had to pull back from the ICE ban of 2035. Banning ICE by then is unrealistic considering the way things work right now. The frog needs to be boiled slowly.
For examples, studded snow tires can tear up the road surface quite significantly, tend to kick up a lot of sharp fine dust. It's such a big problem they're often banned parts of the year in some regions where they're typically used.
Here's some science: https://www.ivl.se/download/18.1ee76657178f8586dfc89b/161951...
It seems to largely suggest that GP is correct (see the figure in 5.3.8 for example), with the caveat that this is mainly a problem in colder regions of the world.
Lastly, as pointed out above, EVs weigh a lot more, so the damage they cause will go up a lot, thanks to that 4th power scaling.
The press on the subject also annoyingly sidesteps a direct comparison. For example, you can read that tires product 2000x the particle emissions as tailpipes, and lots of ultrafines. Notice that statement does not tell you anything about the relative difference in ultrafine production.
Maybe the people who are not affected shouldn't try to guess, when many of as as we are getting older feel the difference and it affects our life.
Alternately, is the issue about road wear particulate as a result of tire contact? That seems more plausible to me.
But, I'm all for taxing cars for their externalities so I welcome these ridiculous anti-EV talking points. We might end up with clean EVs that are taxed by weight which is a double win.
Some are saying: yes it's a massive issue, and some are saying nah it's not, I can't seem to find a consistent view on this issue.
http://jaar2014.middendelfland.net/middendelfland/metdetreks...
or even better!
https://nl.pinterest.com/pin/pin-op-history-color--119486196...
Dont know what it is, some people say tires. Whatever it is, it's a lot and living in cities like this have already shown a lower life expectancy of around 5 years.
So black carbon from diesel truck exhaust (and buses) pollute a lot more than a lot of you think. They call it a 'soup' of pollution of both exhaust and tires. But you should continue to be skeptical of AI driven thought-content :)
Sources:
https://www.sciencedaily.com/releases/2018/09/180910111237.h...
https://news.engineering.utoronto.ca/national-air-pollution-...
https://www.socaar.utoronto.ca/wp-content/uploads/2019/12/Ne...
In Manhattan I’d shower, take the train to work, immediately go wipe my face in the bathroom with a damp paper towel and the paper would have black smudges all over it.
Imagine the long term health implications scaled up to the whole population.
Compared to what?
Are you trying to say that you have already done this cost/benefit calculation and decided that there is nothing which can be done to improve the situation? If not, what are you trying to say?
If you want some reading material about solutions though, there's a lot of stuff out there about reducing car reliance. Building proper public transport infrastructure, building walkable and bikeable cities, that sort of stuff. Keeping the advantages of easy and efficient transportation, while alleviating some of the disadvantages. I can suggest some if you want?
Maybe in the “real world” we should discuss solutions rather than conjure up excuses to accept major problems.
https://www.sciencedirect.com/science/article/abs/pii/S00489...
Plus the upholstery is probably outgassing all kinds of nasty plastic shit ... "new car smell" = cancer.
The last thing we need is a Darwinian advantage for polluters.
"Nevertheless, we should mention that the inhalation dose of commuters could be different from the exposure levels. Dons et al. (2012) found that exposure to BC during travel in motorised transport was clearly higher than exposure while walking or biking (6.3 μg/m3 versus 3.4 μg/m3), but when accounting for inhaled doses, this relationship was reversed. Cyclists seem to receive the highest inhaled PM2.5 dose followed by bus and car passengers (McNabola et al., 2008). However, in the present study we do not examine the inhaled dose of pollutants during commuting due to the lack of studies determining it and also its complexity of interacting factors such as breathing rate, ventilation and/or particle deposition to the respiratory system."
Also, in the study, they said they drove with air-recirculation off, which I believe would mean the outside air does not get filtered. And outside air seems to be a major source of inhaled pollution, since electric vehicles have even higher measured pollution levels than gasoline.
The entire point of the cabin air filter would be to filter outside air in that situation. I can’t think of a reason to have a cabin air filter that would not prioritize that situation first.
We've been thinking about making the sensor portable so it can alert when it's time to mask up because its often hard to be sure if you're not being unnecessarily exposed.
The few days after that I had shortness of breath and trouble concentrating. It was pretty alarming. Not wearing a mask, which I had with me, was a big mistake.
I think your suggestion is excellent.
So portable monitor in my view is overkill, I just check AQI in the area and close windows and run air filter indoors and don't cycle when it's bad.
But if it's a really convenient monitor I'd not mind it! In my experience accurate monitors are not small and not cheap though...
You don't even need a catalytic converter, although it helps with the microscopic amounts of NOx that does get formed.
I know a guy who had one and his verdict was never again.
The valve would freeze on a cold enough day and you couldn’t get it started. He even had it freeze while he drove it.
These don’t seem like impossible issues to solve though.
[0] https://motoryzacja.interia.pl/wiadomosci/ciekawostki/news-p...
In the UK the main problem was that the government went with LPG conversions as the cleaner greener way forward, then got a lot of pushback from car manufacturers who wanted to sell more cars. So in the early 2000s, they pushed diesels as cleaner and more efficient and got everyone to scrap their petrol cars and buy diesels.
And you know how that worked out.
But the long and short of it is, "what happened to them?" comes down to "they didn't sell enough debt to people" is what happened to them.
Pressurized fuel tanks have a larger safety requirement than gasoline or diesel, too; additionally, fueling accidents tend to be much higher energy. In the US, at least, the tanks expire and need to be replaced which is often uneconomical and puts a hard cap on vehicle lifetime.
One of the problems is that conversions need more than just a switch of just gas to LPG. You need a tune and you need an adjustment / expansion of the cooling setup. LPG runs a lot hotter than gasoline and this needs to be managed.
Funnily enough modern gasoline engines are tuned to manage temperature by ... dumping in more fuel.
Which is why your turbocharged 3 cylinder .9L has amazing mpg while driving calmly, but once you push it it proportionally consumes way more.
Once you've got it installed and given it an initial rough setup (not much more than programming in how many cylinders and how large an engine) it'll just trim itself. The LPG ECU maintains a map that makes the vehicle's own ECU think it's running at a perfect mixture on petrol, and is otherwise totally unaware that anything is different.
Older systems are a bit cruder, but still don't need much more than an extra lambda sensor fitted for the gas ECU.
Not the case when you have an LPG system installed.
Whether the piggy-back understands this procedure and and obeys it or fakes it is irrelevant.
If your cooling system cannot handle this increased heat output you'll run into issues. Better fan will help, but again, this is more heat coming from the inside of the cylinder, so certain blocks will handle upgrades better than others.
The gas leaves the tank in liquid form and has to be boiled into a gas. Its boiling point is -40°C, and so the vapouriser is plumbed into the cooling system. This pulls a lot of heat out of the coolant.
I regularly tow at the maximum permitted weight and speed with my LPG-converted Range Rover, and the coolant never gets above its normal 95°C even on the hottest day.
Which is more crash-proof? A metal tank made of 5mm thick steel bolted to brackets welded into the frame of the vehicle, or a leaky plastic bucket tied underneath with a couple of straps?
I've never seen a gasoline or diesel station have enforced safety requirements, but when I was looking at CNG cars, PG&E required pre-registration to access their fueling station, with a required fuel system safety inspection (which you can't pass with an expired tank) and a safety video. And it would be very inconvenient to drive through California without using their fueling stations.
Meanwhile, gasoline stations often run unattended, with no registration or safety inspection.
LPG is stored at about 8-10 bar. That's less pressure than is in an air suspension tank, and only about three or four times as much pressure as in the tyres.
So let's say people pay to switch the infrastructure to support propane vehicles.
Then they switch to electric?
Propane also appears to be less energy dense than Gasoline. So people would be buying more fuel than before.
I don't know, I don't see the consumer coming out ahead on this while EV will have become the standard in the 2030's.
Electric cars aren't particularly clean or economical to make, and you can convert any existing petrol car for about £1000 to run on LPG.
Anything related to mining, well a lot of mining is bad and it's not like internal combustion engines have been all that great for the environment either. So moot imo.
Frankly I think the notion that EV is worse for the environment and battery technology being allegedly bad are just parroted talking points that negate to compare how EV would stack up to combustion technology if you applied the same number of engineering man hours to it but I digress.
Regardless propane from what I can gather isn't that much cheaper than gasoline at least for the U.S. so any potential savings in it being less expensive is easily lost by needing to burn more to go the same distance as gasoline.
Plus the conversion sounds expensive and warranty voiding. Most consumers wouldn't bother.
If you convert a petrol car to run on propane, the exhaust emissions are water vapour and carbon dioxide, with no CO, no HC, and pretty much no nitrogen or sulphur oxides.
This is why things like warehouse forklifts run on propane - you can't die from breathing the exhaust fumes, unlike petrol or diesel.
Typically you'd convert older cars, of which we have plenty. We don't need to make new cars, because there are enough cars for everyone - we just need to make them run cleaner.
It's a nice notion but it's not going to happen.
The whole point of "scrappage schemes" where you can scrap your dirty inefficient old car that only gets 40mpg and buy a new one that is much cleaner and more efficient at 41mpg for only 600 quid a month at 77% APR is to get people as deep into debt as possible.
Because debt is profitable, and clean air is not.
That sounds nice, now tell automakers to stop making cars and just become companies that convert cars and pay pensions.
Propane wants to burn leaner, and burns with a bigger, slower, and hotter bang. You can run a far leaner mixture without pre-ignition (pinking or knocking) because it's got a higher octane number, something like 115RON. You don't get anything like as much soot, you don't get any carbon monoxide, and because of the different proportions of carbon and hydrogen you get more water vapour and less carbon dioxide per mile travelled.
Seny Damayanti, Roy M. Harrison, Francis Pope, David C.S. Beddows, Limited impact of diesel particle filters on road traffic emissions of ultrafine particles, Environment International 174, 2023, https://doi.org/10.1016/j.envint.2023.107888.
It's like barely visible rolling coal and it's non-stop every time the truck is driven.
Just one mechanic sold thousands and since it's software you can be sure it's copied and used by anyone wanting to make a few dollars on the side
https://jalopnik.com/a-mechanic-pleads-guilty-to-selling-tho...
Since many states do not have inspection, once turned off it may be for the life of the truck.
Screen readers and translators don't do well with these characters.
The combined efficiency of all effects happens to have a minimum at 0.3 microns. [1] This is called the "Most Penetrating Particle Size" (MPPS).
For very small particle sizes, filtering mostly works by diffusion (quoting from [2]):
>[Diffusion] is a result of the collision with gas molecules by the smallest particles, especially those below 0.1 μm in diameter. The small particles are effectively blown or bounced around and collide with the filter media fibers. This behavior is similar to Brownian motion and raises the probability that a particle will be stopped [...]
[1]: https://en.wikipedia.org/wiki/HEPA#/media/File:Filteration_C...
"Diesel Oxidation Catalyst (DOC) and Diesel Particle Filter (DPF) has been very effective in controlling the emissions of solid particles and hence BC, but that there has been little change in the liquid mode (<30 nm) particles, and that concentrations of ultrafine particles (<100 nm) still well exceed the threshold for “high” concentrations (>10e4 cm^−3 /24-hour mean) defined by WHO. BC declined by 81% between 2014 and 2021, but the ultrafine particle (<100 nm) count declined by only 26%.
Looks like DPF/DOC filters use mainly interception, but they're not terribly effective at filtering via the diffusion mechanism.
[0] https://www.sciencedirect.com/science/article/pii/S016041202...
Scroll down to “The physics of air purifiers seem simple.” for the relevant bit.