Arsenic: The levels of arsenic in Edgar’s hair were 15 times today’s normal level, and about 2/3 the level associated with symptoms of arsenic poisoning. They did not change significantly over time. Virginia’s hair started at 45 times the normal level today, and twice the level associated with arsenic symptoms, but fell 66%, ultimately ending at a level almost identical to Edgar’s. Since they were in Fordham by this time, and Edgar was still living in the same house two years later, the researchers believe they most likely ingested similar levels of arsenic from environmental sources, such as their drinking water. The much higher level of arsenic collected in the oldest portion of Virginia’s hair could have been due to higher levels of arsenic in either their water supply while living elsewhere and/or the coal used to make illuminating gas.

Lead: Edgar’s lead level fell 33% over the same period, showing that he dramatically reduced his exposure, which in that era would have been primarily from wine and/or patent medications. Although the levels of lead at both ends of his hair sample are 3 to 4 times higher than today’s normal level, they are not high enough to cause symptoms of lead poisoning. But the lead levels in Virginia’s hair ranged from 10 to 13 times higher than today’s normal level -- higher even than the levels found in President Andrew Jackson’s hair after he was shot with two lead bullets -- and are at the low end of levels associated with symptoms of lead poisoning. (Jackson’s lead level dropped dramatically after the removal of the bullets.) Since Edgar and Virginia’s lead levels in Fordham were so substantially different, the researchers believe they are more likely due to some specific form of exposures (such as cosmetics or medications) rather than environmental sources (such as polluted air or water).

Mercury: Edgar’s mercury level increased over a few months by 264%, probably due to the calomel he wrote of taking while in Philadelphia. But even at its highest point, it was still more than 30 times below the level associated with symptoms of mercury poisoning, and only1/2 the level found in President Andrew Jackson’s hair, who (like Poe) was known to have taken calomel medication. Virginia’s mercury level, however, started at a level about that of President Jackson and gradually increased 22%, suggesting that she and Edgar had very different personal exposures.

Nickel: The oldest nickel level in Edgar’s hair was 10 times today’s normal level, and fell 66% as he aged. Although it was higher than normal, it was not high enough to produce symptoms of nickel poisoning. Virginia’s nickel level also fell but by 98.7%, from a level higher than Edgar’s to 20 times lower, suggesting that they had different sources of personal rather than just environmental exposure.

Uranium: The levels of uranium in Edgar’s hair were below the detection limit of the instrument for the size of the samples, which means they contained less than about 8 parts per billion (=0.008 ppm). But the level of uranium in Virginia’s hair when she lived in gas-lit New York City was very high, similar to that found in uranium miners, and approximately 15 times today’s normal level. It was also 100 times the level found in the middle section of her hair. As with Edgar, no uranium was detectable in the end of her hair that grew while living in gas-free Fordham. Since the most likely source of her uranium exposure in New York City was illuminating gas made from coal, to which Edgar also would have been exposed, the researchers conclude that the both she and Edgar were significantly exposed to gas lighting there before they moved to Fordham, where they had no detectable exposure to coal gas or any other sources of uranium.

Vanadium: The levels of vanadium in Edgar and Virginia’s hair were both at the high end of the normal range and neither changed significantly, showing that vanadium apparently cannot be used as a biomarker of illuminating gas exposure.