[hawkinspeter]

From: [url]https://www.sciencemag.org/news/2020/09/it-s-not-just-cars-make-pollution-it-s-roads-they-drive-too[/url]

[quote]The smell of summer in Los Angeles, or any major city, is often tinged with asphalt. A freshly paved road or a new tar roof doesn’t just wrinkle your nose, however: A new study suggests fresh asphalt is a significant, yet overlooked, source of air pollution. In fact, the material’s contribution to one kind of particulate air pollution could rival or even exceed that of cars and trucks.

“It’s a super cool paper,” says Allen Robinson, an environmental engineer at Carnegie Mellon University who was not involved with the research. “Asphalt could be a big, important contributor” to air pollution, he says.[/quote]

Topic

[hawkinspeter]

don simon fbpe wrote:

Would we include this under the umbrella of VOCs https://en.wikipedia.org/wiki/Volatile_organic_compound, alongside such offenders as glues in carpets and furniture, household cleaning, and ironically, air fresheners?

I think it’s not typically included as most places use a definition of substances with boiling points below 250°C for VOCs whereas tarmac is over 300°C.

The article does mention VOCs which produce a surprising amount of pollution:

The researchers estimated the annual emissions from new paving and roofing in parts of Southern California. They calculate that molecules released from asphalt could lead to between 1000 and 2500 tons of particulate air pollution—compared with just 900 to 1400 tons from gasoline and diesel vehicles. (Both sources pale in comparison to volatile chemical products, such as pesticides, coatings, adhesives, cleaning agents, and personal care products, which together contribute 4500 to 9500 tons of particulate pollution per year.)

[don simon fbpe]

Would we include this under

Would we include this under the umbrella of VOCs https://en.wikipedia.org/wiki/Volatile_organic_compound, alongside such offenders as glues in carpets and furniture, household cleaning, and ironically, air fresheners?

[OldRidgeback]

The Americans are a bit

The Americans are a bit behind with the clean asphalt production technology. There’s one firm (Astec) that makes it I know, but it is new technology in the US. We’ve had that a bit longer here in Europe. There are still a lot of old style asphalt plants here in Europe, but they’re being phased out and replaced, or retrofitted with new kits to bring them up to date.

The warm asphalt technology isn’t new exactly, but take-up has been slow as the road construction sector is quite conservative. But it will deal with all the emissions problems, plus some other issues too, as it is produced at a lower temp than releases all the nasty niffs from conventional technology. Producing asphalt at a lower temp saves a lot in terms of fuel, so there’s big incentive to use it for industry as it’ll cut production costs significantly. It also is easier to compact, so there’s every chance it’ll last longer as a road surface too.

[OldRidgeback]

Asphalt is produced at

Asphalt is produced at temperatures of over 140C. That’s the point. But the paper is talking about old production technology that’s already been surpassed.

New asphalt production technology features sophisticated filtration systems and reduces emissions significantly. There are also ‘warm’ asphalt technologies that use lower temperatures (120C) during production and avoid the problem of harmful emissions altogether.

I know of an asphalt plant that was installed here in the UK a couple of years back, located right next to a food production facility. The reason this was allowed by the council was because the emissions from the plant are so low. The food production firm was sceptical but received assurances and since the plant got up and running in the last couple of years, there have been no complaints about smell from the asphalt plant or contamination of food.

In the US, the legislation is a bit behind us in Europe (and the UK still follows EU requirements for the moment at least). In fact the Chinese are actually much tougher on asphalt plant emissions too than they are in the US (and for obvious reasons if you’ve ever been in a major Chinese city when the smog is bad).

 

[hawkinspeter]

Thanks – that’s good to know.

Thanks – that’s good to know. Is that the same in the U.S. which is the main focus of the paper?

[Captain Badger]

So far….

So far….

[ChadCapote]

That could be a misconception

That could be a misconception. I’d read a long time back about how gravel also contributes to pollution. That particular article was a debate if electric cars could reduce pollution, to which the writer argued about the harmful effects of gravel roads and roads in general. 

[hawkinspeter]

Time to switch from road

Time to switch from road bikes to gravel bikes, then?

At least here in the UK it’s rare for the temperature to get as high as that quoted for Los Angeles.

[Anonymous]

Oh shit!

Oh shit!

Who originally campaigned to have the mud tracks macadamed?

Bloody cyclists!

[Author]

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