Mineralogy of the atmosphere
On Thursday, I posted some reflections on one of the talks at the most recent meeting of the Geological Society of Washington. At the same meeting, there was another talk that got my attention, and I wanted to briefly share its findings with the geoblogosphere. The talk was entitled "Mineralogy of the Atmosphere: Assessing environmental and health impacts of airborne particulate matter." It was given by Reto Giere, of the University of Freiburg, Germany. (He's currently in DC as a Visiting Investigator at the Geophysical Laboratory of the Carnegie Institution of Washington.)
Reto's research has lately focused on particulate matter in the air. He collects it and then evaluates it using transmission electron microscopy, X-ray diffraction, and other techniques. The first point he made in Wednesday's talk is that "soot" is a matter of definition. Natural and anthropogenic sources can both be found in the sub-1-micrometer range. If you look at small particulates, Switzerland's environmentally-lauded train system actually generates three times as much "soot" as their traffic output.
So what's in that "soot?" Turns out that a lot of it is anglesite, PbSO4 and some of it is gunningite, ZnSO4'H2O. (There are also droplets of elemental selenium, Se.) The majority of these metal sulfates (and others) are coming from flue gases from power plants. And the thing is, because they're so small, all these goodies end up in our lungs. Reto has run modeling experiments to see what weight-percent of the average person's dose of inhaled metals gets extracted by the lung fluid. In one week, 80% of the zinc was absorbed by the lungs, 55% of the nickel, and 35% of copper. Yum! (I would have been interested to see the actual masses of these absorbed metals compared to the quantities present in a typical vitamin pill, but that wasn't covered.)
There's good news that stems from Reto's work too: the particular "cocktail" of minerals in a sample may be diagnostic of a specific source, which would be useful for forensic identification of polluters. Overall, I found it an interesting talk, on something I'd never really thought about before.
Reto's research has lately focused on particulate matter in the air. He collects it and then evaluates it using transmission electron microscopy, X-ray diffraction, and other techniques. The first point he made in Wednesday's talk is that "soot" is a matter of definition. Natural and anthropogenic sources can both be found in the sub-1-micrometer range. If you look at small particulates, Switzerland's environmentally-lauded train system actually generates three times as much "soot" as their traffic output.
So what's in that "soot?" Turns out that a lot of it is anglesite, PbSO4 and some of it is gunningite, ZnSO4'H2O. (There are also droplets of elemental selenium, Se.) The majority of these metal sulfates (and others) are coming from flue gases from power plants. And the thing is, because they're so small, all these goodies end up in our lungs. Reto has run modeling experiments to see what weight-percent of the average person's dose of inhaled metals gets extracted by the lung fluid. In one week, 80% of the zinc was absorbed by the lungs, 55% of the nickel, and 35% of copper. Yum! (I would have been interested to see the actual masses of these absorbed metals compared to the quantities present in a typical vitamin pill, but that wasn't covered.)
There's good news that stems from Reto's work too: the particular "cocktail" of minerals in a sample may be diagnostic of a specific source, which would be useful for forensic identification of polluters. Overall, I found it an interesting talk, on something I'd never really thought about before.
Labels: environmental, gsw, minerals
0 Comments:
Post a Comment
<< Home