End of summer research at Jamestown

The end of summer is upon us, and I have had much time to reflect on the work I have done this summer. Sampling days at Jamestown were hot, humid and mosquito friendly but were often immediately followed up with respite in the traditionally and characteristically frigid geochemistry lab. During the last few weeks of July and the beginning of August, a new facet of my research was finally introduced: UV Digestion of organic matter. Simply put, the goal of analysing drinking water at Jamestown was to determine whether colonists ingested debilitating or even lethal doses of arsenic and iron. Levels of iron are extremely high, but if the colonists allowed the water to sit in open air essentially all the iron in the water would be oxidized and fall out of solution as a solid. Arsenic does not behave this way and any arsenic in the water will be directly ingested. But, what if there is more arsenic in the water that we aren’t detecting because it is attached to organic matter? This is the new question I have started to pick apart by a method involving UV Digestion of organic material.┬áIn the lab I allow a UV light to pass through the water samples which destroys organic material, therby liberating any arsenic attached to these molcules. I can then re-analyze water samples to see if there is any increase in arsenic concentration, and whether this increase is lethal. I found a doubling of arsenic in one well located between the banks of the James River and the wall of the fort, and a slight increase of arsenic in the swamp surface waters. UV Digestion has been performed on a few samples, but not enough to draw any sort of pattern (let alone conclusion) regarding this new facet of my research.

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