Is the Mercury in Thiomersal Dangerous?

Is the Mercury in Thiomersal Dangerous?

Thiomersal is a preservative that is added to  vaccines to prevent contamination. It contains roughly 49% mercury; therefore a vaccine containing the standard Thiomersal dosage of 50mcg contains 25mcg of mercury. For adults, there are thiomersal free and preservative free vaccines. Thiomersal-free has no thiomersal, while preservative free contains trace amounts, or about .3mcg per dose. Although childhood vaccines can no longer contain thiomersal (as of 1999), the government considers the trace amounts in preservative free versions acceptable, plus, any vaccine that was produced prior may be still be used (assuming its shelf date has not expired).

The FDA set the daily safe limit of mercury at 1.0mcg per kg of bodyweight per day to avoid neurological damage. However, paying attention to the weekly average tends to be a more accurate indicator.

The ultimate question of course is,  “Is it Safe”?

How much mercury can I have “safely”…

  • Average American Male, 86.5kg (190lbs) * 0.1 = 8.65 mcg per day= 60.55 mcg a week = 242.2 mcg a month
  • Average American Female, 74.5kg (165lbs) * 0.1 = 7.45 mcg per day= 52.15 mcg a week = 208.6 mcg a month
  • A Schoolchild, 22.7kg (50lbs) * 0.1 = 2.27 mcg per day =  15.9 mcg a week = 63.6 mcg a month
  • 2 Month Old baby 4.54 kg (10lbs) * 0.1 = 0.454 mcg per day =  3.18 mcg a week = 12.72 mcg a month
  • Calculate your own mercury risk from the seafood you eat. http://www.gotmercury.org/article.php?list=type&type=75

How much mercury is in Tuna…

  • Tuna is considered a safe fish, at least compared to Swordfish or other fatty fish, but it still contains mercury. Chuck light has 0.112ppm of mercury, and white albacore has 0.357ppm
  • So if you eat a can of the popular Solid White Albacore Tuna you are consuming… 170.1grams (6 ounces) * 0.357 = 60.726mcg of mercury. That’s the monthly allowance of mercury for children!
  • The cheaper chuck light… 170.1grams (6 ounces) * 0.112 = 19.05mcg of mercury.

Regardless of my own opinion on vaccination, this is the take home message.

One can of tuna contains 175x more mercury than a vaccine does, plus tuna contains methylmercury, which of the two forms of mercury is more difficult and takes longer for the body to eliminate. BUT, the body only absorbs between 2 and 38% of mercury in the GI tract, that means at max a can of albacore delivers 20mcg of mercury, or as little as  1.0 mcg of mercury, mattering on a slew of variables (hydration, pH, mineral interaction, etc…).

If you are an adult, avoiding a vaccine only because of the trace amounts of mercury seems unwarranted… your food has more of it (which is a problem in itself… another time…). If you decide thats too risky, then quit eating fish too.

If you are concerned about vaccinating your infant, your fears may be warranted. If the mother has mercury in her system it will be transferred into the breast milk, add that to the 0.3mcg in the vaccine, possible multiple vaccines, and you’re likely well over the limit for an infant. Plus, during this critical stage of neurological development a little extra mercury could have a big effect.

In an attempt to bar my personal bias, this article contains no reference to PRO or AGAINST literature on Thiomersal, only numerical facts on mercury contents in the above mentioned foods & preservatives. This is NOT an article on the safety of vaccines in general, or of other non-mercury related concerns of vaccination.

Author: Kristopher Schuster

References

Clarkson TW, Magos L (2006). “The toxicology of mercury and its chemical compounds”. Crit Rev Toxicol 36 (8): 609–62.

http://www.clu-in.org/contaminantfocus/default.focus/sec/Mercury/cat/Toxicology/

http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/Seafood/FoodbornePathogensContaminants/Methylmercury/ucm115644.htm

http://www.cdc.gov/FLU/ABOUT/QA/thimerosal.htm

Yess, Norma J. “US Food and Drug Administration Survey of Methyl Mercury in Canned Tuna,” Journal of AOAC International, Vol. 76, No. 1, 1993, pp. 36-38.

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