[quote=A39Coronet]
and the latest medical “buzzword” - 2.5 micrometer air pollution particles
Actually that's not new, and it's not a "buzzword" either. A brief lecture:
My late toxicology professor used to say back in the 90's about lab air pollution experiments, "Rats can't inhale rocks". In other words, really large particles don't make it into the nose. Particles big enough to stay in the airstream are trapped in the mucus of the upper airways starting at the nose, and usually swallowed or ejected. Really tiny particles (less than 0.5 um) go in and out of the lungs with the air. But those around 2.5 um get sucked in and stick in the alveoli, the microscopic lung sacs where the actual exchange of oxygen and CO2 takes place.
That is why that particular size is important. Especially if they are carcinogenic materials (chemical or alpha-emitting radioactive) that stay in the lung for life and keep building up with exposure over time.
I am interested -2.5 micrometer particle science.
Buzzword to me means “suddenly very much in abstracts” not utterly false.
I have been involved in particle air pollution since 1975 when I was required by law to take a course in “Black Lung” disease due to the new regs in the 1968 Mine Safety and Health law. I decided then, at my Grandfather’s urging, to start wearing a N95 masks/respirators. I have now worn N95s countless hours. My first job underground was as “Curtain Man & Cable Puller” which puts you in the thickest dust. It was known then that Coal has Uranium and Thorium naturally in it., plus Silica varieties, which can cause lung cancer. Some coal seams have layers of volcanic ash mixed in.
In school I had Professors who were involved in the local problem of “Brown Lung” from cotton dust in the many textile mills of the Carolinas, and many mill workers also smoked the cigarettes that were turned out by the Billions in the Durham cigarette factories.
In 1978 I had to take British National Coal Board dust protection and abatement training too.
The NCB is correctly proud that they pioneered mine dust health.
They call it Pneumoconiosis rather than “Black Lung.”
I asked my instructor why the UK standard for dust was 4 milligrams per cubic meter, whereas in the USA the legal limit was 2 milligrams per cubic meter.
He laughed, then walked over to stand over me where I was sitting, and replied loudly in a room of several dozen Newcastle and Yorkshire area miners -
“I was there in the USA as an expert witness. Your Senator Ted Kennedy said, if the British say 4 prevents Black Lung, then I am gonna write our law at 2. I guess Ol’ Teddie was in a hurry, musta had another beach date with a hot teenager.” This got a big laugh.
If really small particles can go directly from air through thin tissue to blood in the lungs, and then can cause diseases, including brain diseases such as dementia where these tiny particles must also pass through the blood-brain barrier, that is scary.
Air pollution is super bad in China and Chinese researchers suspect it does happen.
A huge number of people cook inside over dung fires, or wet, high ash, waste coal fires that don’t have efficient combustion,
and that air pollution is perhaps the worst I have witnessed.
In the 1970s the National Coal Board in the UK designed highly scientific fireplaces and furnaces under the “Real Fire” trade name.
Those were actually smokeless. Very impressive. All gone now.
