Analysis of what effects of frequent exposure to the waters of Great Salt Lake have on Mercury toxicity in humans

There have been quite a few alarming reports of the level of mercury found in birds and spiders that live in and around the Great Salt Lake.  I've emailed the USGS scientist, David Natz, who reported to the news about the dangerous levels of mercury in the Great Salt Lake, but received no response from him.  I've also been warned by a local University of Utah professor about swimming in the Great Salt Lake.  

When I initially studied the possibilities of swimming in the Great Salt Lake, I was concerned and emailed the  GSL Harbormaster, Dave Shearer, who told me that the warnings are for eating ducks that nest and live on the shorelines of the lake, and that it was perfectly safe to swim in.  I took a leap of faith and began my adventure swims in the lake starting in June 2010.  

Over the past 10 months May 2011 - Feb 2012, I have swam 50 times in the Great Salt Lake totaling 136 miles, mostly in the following areas of the lake:

• Great Salt Lake Marina
• North of Antelope Island

Total time immersed in the water: approximately 70 hours

During this time I have probably swallowed a total of 1/2 cup of the highly salinated water among five different incidents where water entered my mouth and I was unable to be quick enough to stop it's flow down my throat.  

Last week I had my blood drawn at the IHC Lab in Bountiful for the purposes of having it tested for mercury toxicity.   My results came back in the mail this evening and the results said my blood contained 3 ug/L.  The report stated that normal range in humans is 0-10 ug/L.  

Here are a couple of documents discussing mercury toxicity in humans:

1. http://www.med.ucla.edu/modules/wfsection/article.php?articleid=311
2. http://ehs.okstate.edu/training/mercury.htm

The second article mentioned above reports that symptoms of repeated mercury exposure include:

1. Gum problems. The gums become soft and spongy, the teeth get loose, sores may develop, and there may be increased saliva.
2. Mood and mental changes. People with chronic mercury poisoning often have wide swings of mood, becoming irritable, frightened, depressed or excited very quickly for no apparent reason. Such people may become extremely upset at any criticism, lose all self-confidence, and become apathetic. Hallucinations, memory loss and inability to concentrate can occur.
3. Nervous system. The earliest and most frequent symptom is a fine tremor (shaking) of the hand. A tremor may also occur in the tongue and eyelids. Eventually this can progress to trouble balancing and walking.

I have not experienced any of the above symptoms.  Being a software developer it often takes a great deal of logical thinking and if I had problems with my nervous system, it would soon become obvious in my performance in my career, which right now is doing extremely well.

My skin is very healthy and is not noticeably irritated with the frequent exposure to the Great Salt Lake.  In comparison, it is slightly irritated with long term exposure to chlorine from swimming pools, than it is from being exposed to Great Salt Lake Water.  

Conclusion:  Swimming in the Great Salt Lake is safe for humans, and I will continue to swim in the awesome body of water.