Fine Particulate Matter and Health Effects

On November 3 and 4, Chad Weldy gave a few presentations on campus. Chad is a PhD student in the Dept. of Environmental & Occupational Health Sciences at the School of Public Health, University of Washington. He graduated with his BS from Huxley in 2007 with an emphasis in Environmental Toxicology; I was glad to welcome him back.

Chad had a busy scheduled. He lectured in my Toxicology 1 class and was the Huxley Seminar Speaker for the week. He was also interviewed on, The Joe Show, a local radio show on KGMI . The second part of the show has Chad's interview.

All of the talks were related to his PhD work on the human health effects of a specific type of air pollution, fine particulate matter (PM2.5). He focused on the impacts of diesel exhaust (a source of PM2.5) on cardiovascular disease and cardiovascular related mortality. With the proposed coal terminal in north Whatcom County and a potential increase in diesel trains as a result, the talk was very quite relevant to current issues here. What was interesting to me was that studies support increased myocardial infarctions (heart attacks) when PM2.5 was high, which can occur when there are weather inversions and sources of PM2.5 (for example, from wood stoves or diesel exhaust). Even more interesting is that a recent epidemiological study found an increased incidence of heart attacks during air pollution episodes, but the authors found a decrease in heart attacks following the episode. They concluded that the air pollution may have shifted the timing of the heart attacks forward in people who would have had heart attacks despite the air pollution episode. As Chad stated, though, this is of debate in the scientific community right now. What doesn't appear to be of debate is that older people are more at risk of heart attacks during acute exposures to PM2.5 from air pollution.

The Huxley Seminar was recorded and is available on Youtube here. Great work Chad!

Additional Resources:

• Dockery et al. 1993. An Association between Air Pollution and Mortality in Six U.S. Cities. New England Journal of Medicine: 329:1753-1759
• Katsouyanni et al. 2001. Confounding and Effect Modification in the Short- Term Effects of Ambient Particles on Total Mortality: Results from 29 European Cities within the APHEA2 Project. Epidemiology:12(5).
  
• Tonne et al. 2009. Traffic particles and occurrence of acute myocardial infarction: a case–control analysis. Occup. Environ. Med.:66:797–804
• Bhaskaran et al. 2009. Effects of air pollution on the incidence of myocardial
  infarction. Heart: 95:1746–1759.

Read more here: http://www.bellinghamherald.com/2011/11/03/2256496/wwu-to-host-air-pollution-lecture.html#storylink=cpy

An opportunity to comment on Atrazine....

1) EPA Seeks Comment on Save the Frogs! Atrazine Petition (from Mary-Jean Lormand, EPA Pesticide Program Updates)

EPA is seeking public comment on a May 2011 petition from the amphibian conservation group, Save the Frogs, requesting that the Agency ban the use and production of atrazine. EPA asks that comments on the Save the Frogs petition be submitted within 60 days, by November 14, 2011, to docket EPA-HQ-OPP-2011-0586 at Regulations.gov. EPA will review all comments submitted before responding to the petition.

For further information about EPA's regulation of atrazine, visit its Atrazine Updates Web page, http://www.epa.gov/oppsrrd1/reregistration/atrazine/atrazine_update.htm .

Interesting Articles:

• Rohr JR, McCoy KA 2010. A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians. Environ Health Perspect 118:20-32. http://dx.doi.org/10.1289/ehp.0901164

Trojan Horses

I attended a lecture recently by Fabienne Schwab on the effects of diuron and carbon nanotubes (CNT) to algae. Diuron partitions to a great extent to the CNTs. Depending on your perspective, this can be beneficial or detrimental. As a remedial technology, it has been suggested that the CNTs (and other carbon nanoparticles) can help to remove contaminants through sorption or by chemically modifying the contaminants. From a toxicological perspective, however, the sorption mechanism may cause further problems by concentrating the toxic contaminants. The term Schwab used to describe the most concerning problem with this is that these CNTs can act like a Trojan Horse and deliver highly concentrated environmental toxicants (like diuron) to an organism - this is not good. The term Trojan Horse is also being used by the medical community where the nanoparticles are used to deliver medicine to targeted areas - this is good. In my opinion, all of these perspectives (and more, for example, the question of how fate and transport is affected needs to be addressed) are needed to help manage uses of nanotechnology, particularly when there is the potential for releases into the environment.

Interesting Articles:

• Rajan, C.S. 2011. Nanotechnology in Groundwater Remediation. International Journal of Environmental Science and Development, 2(3):
  
• Li, X., Zhao, H., Quan, X., Chen, S., Zhang, Y., and H. Yu. 2011. Adsorption of Ionizable organic contaminants on multi-walled carbon nanotubes with different oxygen contents. Journal of Hazardous Materials, 186(1): 407-415.
  
  

More ISE work

I've been to Geneva a few more times and am working at my Eawag lab now. We were able to get the limit of detection for Ag down one order of magnitude, two orders of magnitude would make me very happy. We

Learning to make membranes for ISEs

I just spent two days at the University of Geneva learning to make polymer membranes for Ion Selective Electrodes (ISE). A post-doc (Gaston) working in Eric Bakker's research group helped me with the process. Making the membranes was actually quite easy - with the right tools and recipe, we made 3 membranes that look like small contact lenses. The membranes are being conditioned now in different concentrations of Ag. The goal of this is to use the ISEs to decrease the detection limit of Ag+ in solution and minimize interference associated with the matrix. I go back on Monday to put the ISE together and start optimizing the solutions for my experiments.

These are the polymer membranes... For the scale, the unit conversion is that one Swiss half franc (shown here) is about the size of a US dime...

Here are two papers to look at if you want to learn more about ISEs for trace metal analysis: Note these are not for the squeamish... start with Bakker and Pretsch 2002 as an nice introduction.

• Bakker, E. and E. Pretsch. 2002. The New Wave of Ion-Selective. Analytical Chemistry, August 1: 420A - 426A.
• Szigeti, Z., Malon, A., Vigassy, T. Csokai, V., Grün, A., Wygladacz, K., Ye, N., Xu, C., Chebny, V., Bitter, I., Rathore, R., Bakker, E., and E. Pretsch. 2006. Novel Potentiometrix and Optical Silver Ion-Selective Sensors with Subnanomolar Detection Limits. Analytica Chimica Acta, 572:1-10.
  

Great Video -

This video (Caught in a Bad Project) made the rounds at Eawag several months ago, and I dare say the song still gets stuck in my head on occasion. Anyone who has done a scientific research based graduate degree will find parts of this spot on. I particularly love what they used for the costumes - 10 ml pipette tips make up the bodice of one outfit with biohazard bags completing the skirt. The other is lovely compliment of absorbent lab bench pads... brilliant!