There was a great podcast interview with Dr. Karen Clay about this finding and area of research back on November 7th.[0] She discusses how they evaluate the ef

There was a great podcast interview with Dr. Karen Clay about this finding and area of research back on November 7th.[0] She discusses how they evaluate the effect from wildfires. Also, how they trace sources by analyzing PM2.5 composition--but how that's becoming much harder as the mix of these particles is becoming much more ambiguous than it used to be. Good wonky discussion of the science. Not in the interview, but another of the surprising things I read about local pollution from transportation over the last year is that tailpipe emissions are now a minority of PM2.5 contributions from most cars. Tailpipes have become cleaner over the last few decades, so braking and tire wear now contribute as much. The biggest contributor is something called "resuspension." Vehicles slowly grind up debris or roadway surfaces into finer and finer dust, then kick it into the air where it just hangs. The implication is that average vehicle weight, prevalence of regenerative braking, and frequency of street cleaning can all have much more significant impacts on local pollution than other measurers you might expect, like fuel efficiency, emissions check programs, or even electrification.[1][2] [0] https://traffic.libsyn.com/secure/neolibpodcast/Karen_Clay_final.mp3?dest-id=765425 https://traffic.libsyn.com/secure/neolibpodcast/Karen_Clay_f... Don't be thrown by the podcast name, the discussion of the underlying science is very apolitical. [1] Local pollution is obviously not the same as CO2, which requires a different analysis and is more from tailpipes. But the scientific consensus is that PM2.5 leads to 200,000 early US deaths a year, and as the above podcast mentions, we're not just talking about the elderly or infirm. These are independently important issues. [2] EVs have many advantages, but, counterintuitively, removing the tailpipe only marginally reduces PM2.5 from roadways: https://www.ridef2.com/blog-del-direttore-ridef/will-electric-vehicles-contribute-less-particulate-matter-pm10-and-pm25-to-our-air-recent-analysis-and-meta-analysis-conclude-negligibly-and-policies-to-reduce-number-and-weight-of-vehicles-are-needed4720595 https://www.ridef2.com/blog-del-direttore-ridef/will-electri... I don't take from that that EVs are bad-- just that we need to combine it with other efforts and technologies to reduce local pollution.