Here is the narrative: if we reduce manmade greenhouse gases and their companion aerosols, like PM2.5, we will reduce global warming and improve our health. Unfortunately, the climate is a bit more complex. Our best plans come with unintended consequences. A new study shows that reducing those manmade aerosols also increases the “climate forcing” bringing about global warming.
PM2.5
It's tough not to run across an article linking – by association – air pollution with adverse health effects. Over time scientists have focused more of their research on one component of our air: PM2.5. A new study has identified some of the smallest particles within PM2.5 in our central nervous system.
To discuss the Draft CASAC Report on EPA’s Draft Supplement to the 2019 Integrated Science Assessment (ISA) for PM and the Draft CASAC Report on EPA’s Draft PM Policy Assessment (PA).
In an essay in the London Review of Books, David Wallace-Wells contrasted the 5.5 million annual global deaths from COVID [1] with the 7 million deaths attributed to air pollution (AP) projected by the World Health Organization [2]; he bemoaned the lack of attention being given to the latter. [1] He noted that other AP mortality estimates run as high as 8.7 million and 10 million if indoor air pollution were included. This is getting downright scary.
The World Health Organization (WHO) adopted a dose-response function for PM2.5 that lumps outdoor ambient air quality, second-hand (passive) smoking, and indoor household air pollution. It has been used in 80 published studies of the “Global Burden of Health” (GBD). Here I take a closer look and incorporate some additional risk estimates.
The New York Times recently featured a new study by Christopher Tessum and colleagues on disproportionate exposures to people of color from fine particle (PM2.5) emissions, raising questions about environmental injustice.
Dear Director-Designee Regan:
What an opportunity you now have to move the EPA's goals and objectives into the 21st century!
As an avid reader of the New York Times, it pains me greatly to read about a familiar subject that has so many errors and misconceptions. Especially when COVID-19's impact on society is being discussed.
Without a doubt, our world is now quieter since sheltering began, and we can imagine that the air smells sweeter. These are good things but purchased at the terrible costs of COVID-19 suffering and death and devastation of the global economy. The environmental scientist in me thought about lessons to be learned from our present situation.
"Although the epidemiology of COVID-19 is evolving, we have determined that there is a large overlap between causes of deaths of COVID-19 patients and the diseases that are affected by long-term exposure to fine particulate matter (PM2.5).”
It is a great leap from overlap to claiming PM2.5 results in "excess" mortality from COVID-19. But what the heck, why let the fear generated by COVID-19 go to waste?
PM2.5 designates a near-ubiquitous air-polluting particle that frequently appears in the scientific literature as well as popular press news items. But few of us really know what they are talking about, mainly because it is just one characteristic of a complex category.
Air pollution remains a contentious issue. While everyone is in favor of cleaner air, there is less unanimity over which pollutants, in what concentrations, can harm our health. The linkage between air pollution and disease is beset with problems of accurately identifying a dose-response (a biologic gradient), a clear temporal connection, and, most importantly, biologic plausibility – how does a pollutant cause a disease.