Faulty FDEP science drives unnecessary Florida mercury scare
By Willie Soon
Regulatory actions being debated in Florida should raise bright red flags for Sunshine State residents, other US states, and even other countries.
On May 24, the Environmental Assessment and Restoration Division of the Florida Department of Environmental Protection (FDEP) issued a seriously flawed draft report, proposing much stricter limits for mercury in Florida's river, stream, lake and coastal waters. The FDEP claims the rules are based on sound science and will improve environmental quality and public health.
However, my studies of mercury (Hg) and its biologically toxic form, methylmercury (MeHg), over the past ten years make it clear that the new limits are not scientifically defensible.
Not only would they raise electricity costs, while bringing no health or environmental benefits. The new standards, along with statements made by the DEP in public forums, would actually harm people's health.
First, the FDEP is wrong in claiming that mercury pollution is a new, manmade phenomenon.
The Department cites a 2008 paper that reported average mercury levels of 0.25 parts per million (ppm) in the hair of Florida Panhandle women of childbearing age (16 to 49). However, a 2002 study of 550-year-old Alaskan mummified bodies found hair mercury levels five to eighteen times higher: an average of 1.2 ppm for four adults and 1.44 ppm for four infants – and 4.6 ppm in one mummy!
Equally troubling, the FDEP draft report cited a 1972 study, but failed to highlight the study's conclusion that mercury levels in the past were at least as high as those in today's tuna. In a related study, Princeton University scientists expecting to find a 9-26% increase in MeHg instead found no increase (and actually a slight decline) in mercury levels in tuna caught between 1971 and 1998. The Princeton researchers concluded that mercury in fish is not related to human emissions, which continue to decline in the USA.
Even more important, the FDEP draft report failed to consider a 17-year-long Seychelles Islands study that found no harm, and no indications of harm, from mercury in children whose mothers ate five to twelve servings of fish per week – far more than most Floridians consume.
In establishing MeHg exposure risks from fish consumption, the researchers concluded that no consistent patterns exist between prenatal MeHg exposures and detailed neurological and behavioral tests. They also concluded that, despite remote but potential MeHg risks, "ocean fish consumption during pregnancy is important for the health and development of children, and the benefits are long lasting."
Moreover, the latest Centers for Disease Control data show blood mercury levels for U.S. women and children are already below EPA's "safe" levels for mercury – and EPA's standards are the most restrictive in the world. In addition, selenium in nearly all fish is strongly attracted to mercury molecules and thus protects both fish and people against buildups of methylmercury.
By scaring women and children into eating less fish, and thus getting fewer Omega 3 fatty acids, FDEP's misleading literature on "dangerous mercury levels" in fish will actually impair their health.
Second, the FDEP failed to note that natural sources dwarf human mercury emissions.
Forest fires in Florida alone emitted an estimated 4,170 pounds of mercury annually between 2002 and 2006. This single source of local mercury emissions is significantly higher than mercury emitted in 2009 from all manmade mercury sources in Florida, including coal-fired power plants (which emit less than 1,500 pounds per year).
The FDEP draft report did note that volcanoes are an important source of global mercury emissions, but failed to explain how enormous this natural source is. In fact, recent studies calculated that volcanoes, subsea vents, geysers and other natural sources emit up to 2 million pounds of mercury per year.
These natural sources explain why it is unsurprising to find high levels of mercury in samples taken years ago in Florida fish, panthers and raccoons – long before coal-fired power plants were on the scene. Mercury has long been part of our environment, in ocean and terrestrial waters, and in Earth's rocks and soils.
Today, mercury from natural sources represents the vast bulk of all the mercury in our atmosphere. Even eliminating 86% of all mercury from Florida's power plants (as the FDEP proposes) would bring trifling environmental and health benefits – while raising electricity rates for the state's families, retirees, schools, hospitals and businesses, costing jobs, and adversely affecting human health and welfare.
Third, the FDEP is wrong when it says mercury "pollution" in Florida's watersheds and fishes is increasing.
Since the 1970s, contaminants in fish have been monitored increasingly each year. More advisories are being issued simply because of increased sampling by state agencies, and "not necessarily due to increased levels or frequency of contamination," as even the U.S. EPA acknowledges.
Finally, FDEP's proposed new mercury limit for Florida's inland and coastal waters is an unjustifiably low 1.25 parts per trillion – which is equivalent to 0.00000125 ppm and 125 seconds in 32 million years!
The Department also assumes Hg levels in water are directly related to Hg levels in fish tissue. In fact, no such relationship exists. Indeed the FDEP draft report admits as much, when it says (page 58), "Using the data collected for the [Florida Mercury Project], no relationship is observed when comparing total mercury in the water column to total mercury in fish tissues."
It's also worth noting that even a bottle of Hunt's tomato ketchup or Jack Daniel's barbecue sauce contains at least 50 times (!) more mercury than what Florida proposes to permit in its waters.
One has to wonder why the FDEP is so intent on setting mercury levels below those that exist in nature – and why it is so reluctant to disclose, explain or discuss publicly available information from the scientific literature, so that all concerned Florida citizens can study it themselves.
Scientific inquiry must be above political pressure and partisan advocacy. Good decisions can arise only if the scientific evidence and knowledge are examined fully, without selective bias.
The FDEP needs to reconsider its mercury rulemaking, and this time base it on actual science. So do other states, the U.S. Environmental Protection Agency, and other countries considering similar actions.
Dr. Willie Soon is an independent PhD scientist, who for the past ten years has studied the biogeochemical nature of mercury in our environment and its effects on human health. The views expressed here are solely his own.