Florida’s Secret Mercury Factory
By Alan Farago
Remember how Big Sugar said the problem in Florida’s estuaries was septic tanks adjacent to the Indian River? They say the same about the mercury problem in the Everglades and Florida waterways: it’s someone else’s fault. Not of course that Big Sugar fails to clean up its pollution.
The same sort of wizardry applies to how Big Sugar talks about mercury. Let’s break it down:
For mercury contamination to pollute aquatic ecosystems, the mercury must first be transformed to the powerful neurotoxicant methylmercury. Once methylmercury is formed, it can readily enter the base of aquatic food chains and accumulate at increasingly higher concentrations up the food chain from algae to predatory fish and ultimately to terrestrial wildlife such as wading birds and mammal species, including the endangered Florida panther.
This process is known as bioaccumulation and can easily result in concentration increases of methylmercury in fish by factors of over one million relative to methylmercury concentrations in the water column of the Everglades. How does it happen?
The bacteria largely responsible for producing methylmercury require sulfate to support their metabolism.
Sulfate concentrations are elevated across much of the Everglades. The magnitude of this contamination can reach factors up to and greater than 50 compared to background levels, depending on location. Those excess concentrations of sulfate are largely due to one source: farming practices involving the drainage of flooded soils and the use of elemental sulfur as a soil amendment in the Everglades Agricultural Area.
In short, sulfate is a primary driver of the production of methylmercury. The pervasive and high levels of sulfate contamination–largely due to EAA farming practices–are believed by most scientists to have greatly exacerbated the methylmercury problem.
Just like water policies protecting Big Sugar first are wrecking our estuaries, rivers and bays, farming practices tolerated by the state of Florida are spreading pollution into Florida’s most treasured wetland.
Because the muck soils in the EAA are both low in essential micronutrients, and because limestone present in the soils binds phosphorus, the farmers need to apply sulfur to acidify the soils and release these nutrients.
The problem with sulfur is that it doesn’t stay on sugar fields; it flows into the Everglades. So, how have the State of Florida and the South Florida Water Management District reacted to the scientific realities of methylmercury?
Sugar’s position, as usual: “Don’t tell us how much water we need or when we can have it, don’t tell us we can’t drain our fields dry even if it endangers local communities and causes toxic discharges, and don’t tell us how to use sulfur or any other soil additive.”
The simple truth is that, either through benign ignorance or willful indifference, the state of Florida and the district do not even require sugar farmers to report how much sulfur they are using.
Big Sugar represents a secret sulfur source: “The amount of total sulfur used in various soil amendments, fertilizers, and fungicides in the EAA is unknown.” (‘Sulfur in the South Florida Ecosystem,’ Orem et al., Critical Reviews in Environmental Science and Technology, 3 March 2011, page 262.) A more recent estimate of the amount of sulfur applied to the EAA is nearly 19,000 tons per year (Landing, 2014).
When you consider that the practice of applying sulfur as a soil amendment has been occurring over a period of many decades in the EAA, you get the idea.
“Overall, it appears that much or most of the sulfate present in EAA canals originates from the EAA lands. The broad use of sulfur in agriculture (present and legacy sulfur in soil), and the elimination of other sulfur sources (groundwater, wet/dry deposition) as inputs to canals suggests that soil oxidation and present sulfur use in the EAA accounts for the major proportion of the sulfate load to the Everglades.” (Orem et al, page 263)
So why aren’t the facts of methylmercury more widely broadcast to the public?
For the same reason that the state ignored the science of water quality and allowed Big Sugar to dictate a deep reservoir in the Everglades in the recent session of the legislature, and not the addition of significant lands for water treatment and cleansing purposes.
Big Sugar makes money at your expense, literally, from your wallet and in threats to your health. Not idle threats. Methylmercury is deadly serious business, and Big Sugar routinely buries its cost in your waterways.