Unfortunately, nearly 40% of the patients that I test from this area of Florida have high levels of mercury (as tested by RBC mercury levels with Genova). The patients with the highest levels of mercury are affected by anxiety, depression, and neuropathies that have usually been written off as idiopathic - etiology unknown - and treated with various psychotropic prescription medications.
I usually mention the large fish and amalgam fillings as areas of caution. However, I realized I have been neglecting the fact that we have a Portland cement plant (formerly Florida Rock and formerly Vulcan; now Cementos Argos) just a few kilometers west in Newberry that is putting out over 100 lbs of mercury per year into the air that blows over Gainesville. It now has a production capacity of 1.6 million tons per year.
Limestone heated in the kilns contains mercury that turns to vapor in high temperatures, and some of the fuel burned at kilns (often old tires) can contain mercury, too. Some vapor escapes through smokestacks and generally settles to the ground less than 100 miles from the factory. The EPA sets a daily safety limit of 0.1 mcg/kg for ingestion. That's approximately 7 mcg per day for a 150 lbs person. Assuming 100 lbs of mercury is released per year, that equates to a little more than 120,000,000 mcg per day released into the air.
Looking at the mercury deposition maps and fish tissue mercury maps, Florida does seem to have a problem with excess mercury. Between the coal-fire plants, the cement plants, and the paper mills (in Georgia), we have something to be concerned about. The EPA has been blocked and delayed a number of times on setting limits the output of toxic chemicals from cement plants. Currently the proposal calls for 9/2015 limits of 55 lbs per million tons. The US is the only country in the world to use non-SI units for measurement, which (in this specific case) are not interconvertable with units in other countries of the world. This makes comparing our limits to limits around the world very difficult. Germany and Sweden (where dental amalgams have been illegal since the 1990's) have some of the toughest limits on mercury released from cement plants.
"Mercury poisoning is a serious threat to our health. While adults can have severe reactions to mercury poisoning – typically brought about by consumption of fish tainted with methylmercury, a highly toxic mercury compound – young children and unborn babies are especially at risk. This is why women are strongly cautioned to avoid consumption of many kinds of fish before, during, or right after pregnancy. Exposure to methylmercury while still young or in the womb can have an irreversible impact on a child's development, including birth defects, brain damage, reduced IQ, and difficulty with reading, writing, and learning.
The EPA estimates that more than 300,000 babies are born every year with an increased risk of learning disability due to in utero exposure to methylmercury.6 Cement plants are among the worst mercury polluters. The EPA's recently finalized health protections will reduce cement plants' mercury emissions by more than 90 percent – in addition to dramatic cuts in other pollutants that impact our health such as lead, acid gases, and soot."