For centuries, mercury has been used in thermometers for reading our body temperatures, but now we measure mercury levels to see if seafood is safe to eat.1-4 If you are hungry for fish, maybe trout would be a good choice.1
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood.2
A recent study of estuarine gamefish (such as striped bass) suggests that about half of what is catchable is not healthy for eating due to excessive levels of methylmercury, the methylated compound version of metallic mercury.1,2
But the toxicity measurements are not uniform throughout the estuarial waters of the six-state region, although the overall averages match much of America. About 45% of fish tested contain methylmercury at unsafe levels.2,4,5
But why should we care about mercury which is helpful in many contexts?
The bacteria-fixed methylated mercury compound methylmercury is the organic form dangerous to humans because it is a neurotoxin. It is especially harmful to people who are very young in development, from preborn to small children, potentially interfering with neurological development needed for motor skills and brain development.5
Accordingly, mercury contamination—especially as to how it enters into the human food web—is worth studying.4,5 Accordingly, the USGS-led team of investigators collected about 8,000 data samples from 600 locations.1,2
We compiled fish Hg data from state monitoring programs and recent research efforts to address this knowledge gap and provide a comprehensive assessment of fish Hg concentrations in the watershed’s freshwater habitats. The resulting dataset consisted of nearly 8000 total Hg (THg) concentrations from 600 locations. Across the watershed, fish THg concentrations spanned a 44-fold range, with mean concentrations varying by 2.6- and 8.8-fold among major sub-watersheds and individual 8-digit hydrological units, respectively.2
But many of these methylmercury bioaccumulation results are not encouraging. Even though God has wondrously designed our bodies—and those of other creatures including mammals, birds, fish, and reptiles—to purge out useless and harmful substances, the digestive and excretory systems can only process so much, so fast.6,7
Piscivorous (fish-eating) safety benchmarks for humans, birds, and predatory fish were exceeded from one-third to one-half of the time depending upon which fish-eating safety standard was applicable.
The findings underscore the importance of checking for public health advisories before eating any wild-caught fish, said James Willacker, the study’s lead author.1
Due to food-chain dynamics, methylmercury accumulates most in the apex (top) predators, so the largest gamefish are likely to have the highest concentration of mercury in their meat.8
So what are the comparative results of the study for fish-eaters?
Toxins are something we must take seriously in this fallen world.7,8 Before Adam sinned in Eden, triggering the death-and-dying process for both mankind and beasts, the interaction of toxins and detoxification systems was perfect.
However, the detoxification dynamics that Adam and Eve enjoyed, before their bodies became sin-cursed, is not what our bodies now experience.6-9
So, if you’re fish-hungry in one of the Chesapeake Bay-drained states, skip the striped bass—go for trout. At present that’s how some of us read the mercury.
References
1. Cox, J. 2020. Mercury Widespread in Chesapeake Bay Headwaters Fish. Chesapeake Bay Journal. Posted on bayjournal.com June 30, 2020, accessed July 2, 2020.
2. Willacker, J. J., C. A. Eagles-Smith, and V. S. Blazer. 2020. Mercury Bioaccumulation in Freshwater Fishes of the Chesapeake Bay Watershed. Ecotoxicology. 29:459-484.
3. Regarding the usage of mercury thermometers in Europe, see Johnson, J. J. S. 2018. “Volksdeutsche by the Dozen, Part Eight: Refugees in Austria, Fleeing Post-WWII Europe for America—The Jakob & Katarina Webel Family Journey to a New Home.” Journal of the German-Texan Heritage Society. 40(1): 38-54, especially page 50.
4. Eagles-Smith, C. A., J. T. Ackerman, J. J. Willaker, et al. 2016. Spatial and Temporal Patterns of Mercury Concentrations in Freshwater Fish Across the Western United States and Canada. Science of the Total Environment. 568: 1171-1184.
5. Rosenfeld, P. E., and L. G. H. Feng. 2011. Risks of Hazardous Wastes. Norwich, NY: William Andrew / Elsevier, pages 223-235.
6. Matthew 15:17. The human body is designed to expel toxic foods, as food-poisoning investigations illustrate. For example, see Török, T. J., R. V. Tauxe, et al. 1997. A Large Community Outbreak of Salmonellosis Caused by Intentional Contamination of Restaurant Salad Bars. Journal of the American Medical Association. 278(5): 389-395.
7. Regarding the human body’s expulsion of ingested toxic foods, see Johnson, J. J. S. Micro-Plastic Wastes, European Dippers, and the Genesis Mandate. Creation Science Update. Posted on ICR.org June 4, 2020, accessed July 2, 2020. For another example, marine reptiles discharge heavy metals by sloughing off old skin. Guliuzza, R. J. 2020. Shedding Toxins: A Surprising Role for ‘Industrial Melanism’. Creation Science Update. Posted on ICR.org March 5, 2020, accessed July 2, 2020. In humans, toxins—including heavy metals and drugs—also accumulate in hair and nails, so forensic scientists use hair/nail toxicology analysis to provide corroborative (or impeachment) evidence regarding eyewitness reports. See Daniel, C. R., B. M. Piraccini, A. Tosti. 2004. The Nail and Hair in Forensic Science. Journal of the American Academy of Dermatology. 50(2):258-261.
8. Gilmour, C. and G. Riedel. 2009. Biogeochemistry of Trace Metals and Metalloids. In Encyclopedia of Inland Waters. Gene E. Likens, ed. Norwich, NY: Academic Press / Elsevier, 7-15. Gilmour and Riedel note: “Methylmercury [MeHg] concentrations increase by roughly a factor of 10 at each step through a food chain, and MeHg fish tissue concentrations increase substantially with age. Of the ‘persistent bioaccumulative pollutants,’ only PCBs exhibit comparable bioconcentration factors. … Many trace elements are essential micronutrients (i.e., Fe, Mn, Cu, Ni, Mo, Se, and Zn), acting as catalysts in enzyme systems. Others, like Hg and Pb, serve no known physiological function in organisms.”
9. Guliuzza, R. J., and F. J. Sherwin. 2015. Does Our Immune System Indicate Disease Before the Fall? Acts & Facts. 44(1): 17.
*Dr. Johnson is Associate Professor of Apologetics and Chief Academic Officer at the Institute for Creation Research.