Road Dust and PM 1

[TugboatEng]

On my commute this morning there was a news story about particulate matter and premature death. They made the claim that PM causes up to 50,000 premature deaths in the state of California annually. The authors were using this to push for electrification of cars.

This seems counter-intuitive to me. Modern engines already put out very little PM. Prior to 2012 (3 years before full Tier 4 implementation) diesel PM was only 8% of PM2.5. At that time most engines would have been Tier 1 and Tier 2 which are allowed to emir 15-40x the PM of the current Tier 4 standard.

Road dust from abrasive wear as cars roll over it must make up a substantial portion of PM if combustion particulate is so low. In that case, wouldn't the additional wear from heavier electric vehicles counteract or even reverse any gains from electrification?

It also is concerning that road dust contains more harmful particulates such as metals and silica.

 

One must make the distinction between an emissions and a pollutant...

One might presume this distinction is merely engineer-grade pedantry at work, but unfortunately one would be mistaken.

One might also begin to suspect this venerable forum has recently degenerated into social media (or antisocial, it's the same difference). Unfortunately one would be correct.

One would do well in these circumstances to take the high road, where mud cannot reach, and where access to ideas is improved. That's unfortunate.


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[CWB1]

The trouble with labeling them as pollutants is that harm comes with concentration not merely release as the word implies, and we need to ensure clarity when communicating to the (often clueless) public. Drink too much water or breathe air containing too much non-O2 and you'll die, under most conditions tho those compounds are healthy and/or harmless. Tailpipe emissions are the same in that PM, NOx, COx, and HC all naturally exist and are harmless in reasonable concentrations. Unfortunately bc large emission generators also often are large emission reducers governance will always be a bit convoluted to establish where individuals and companies are regarding their overall net effect.