Distal transport and fate of organic compounds
Organic chemicals are prevalent in our everyday lives. Take a moment to look around. Everything from the chair you are sitting on, the computer you are using, to the soap you use to wash your clothing, all contain a variety of chemicals. Many of these compounds are essential for our health, but may slowly leach into the environment. And we don't know what happens from there: Do they travel far away? Do they degrade? Do they accumulate in plants and animals? Do they chemically change into something entirely new?
My current research is focused on one specific type of compound: Polybrominated Diphenyl Ethers (PBDEs). These compounds are used as flame retardants in a variety of household goods such as foams (i.e. couch cushions) and electronics. Flame retardants have gained a lot of attention as we increasingly (and disturbingly) discovery them all over the globe. Even worse is that some studies suggest they may accumulation in animals fats (particularly the charismatic polar bears). Yet, scientists still don't know about the fate of these compounds in sunlight Arctic surface waters. This research takes me north to Arctic Alaska to examine what happens to the compounds once they enter the environment.
I also recently received a certificate of achievement for my oral presentation of this research at the American Chemistry Society conference (Fall 2012). ACS members may view a recording of the presentation here.
UPDATE: It's done (almost)! I am still working on writing up my last of three papers about this research, but the dissertation is written and defended!
Formation of dissolved organic matter in Antarctica
Dissolved organic matter (DOM) is a complex and diverse pool of compounds that is found in every water system in the planet. DOM forms from the natural breakdown of terrestrial organics (like plants and animal debris) and microbial activity. DOM participates in a range of important processes including carbon cycling/sequestration, UV shielding for aquatic organisms (natural sunscreen!), metal speciation, and organic contaminant binding, transport, and degradation. Despite the importance of humics in the environment, little is known about the processes and reactions governing the formation of humic and fulvic acids. I am part of a project focused on examination of how microbial dissolved organic matter forms in supra-glacial (on the surface of the glacier) environments.
You may be thinking: "Well, if DOM is in environments all over the world, then why travel all the way to Antarctica to study this stuff?"
In most locations in the world, DOM is a mix of old and new components that forms from the degradation of both terrestrial (plants) and microbial organic matter. This results in a complicated cocktail and makes it nearly impossible to discern how DOM forms and what the final compounds look like. Antarctica is located too far south for any plants to grow, so all the organic matter present in the lakes and rivers comes from only activity. The DOM found on the surface of glaciers is also all fairly young, which makes the Antarctica a unique "natural laboratory" where we can study the formation of microbial DOM in the environment while it occurs!
Think of the mature organic matter as towers made out of blocks of different colors and different shapes -- it will take you a while to sit down and describe each block color and shape. However, the DOM in Antarctic is much easier to study -- it is like only having individual blocks that are all similar colors.
I am currently working on writing a paper about our findings in Antarctica. I also presented the results of this study at the American Society of Limnology and Oceanography (Winter 2012) and the Gordon Conference (Summer 2012) Click here to see the poster.