Current Hair Mercury Levels in Japanese: Survey in Five Districts.

The Scientific Paper:

Current Hair Mercury Levels in Japanese: Survey in Five Districts. Akira Yasutake, Mituki Matsumoto, Masako Yamaguchi, and Noriyuki Hachiya of the National Institute for Minamata Disease. Tohoku Journal of Experimental Medicine (Tohoku J. Exp. Med.) Vol. 99, pp.161-169. 2003.

Review This Scientific Paper’s Abstract:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=
PubMed&list_uids=12703660&dopt=Abstract

The Purpose of this Study:
This is a study to learn the current amounts of mercury found in the hair among the general populations of different regions in Japan where a lot of fish and/or shellfish is regularly eaten.

Some Background, Methods, Results, Caveats, and Other Select Points:

• This peer-reviewed, scientific paper was published in 2003.
  
• The amount of mercury in a person’s hair tells the scientists the levels of mercury in that individual’s body for a certain time period in their life.
  
• These scientists collected and analyzed hair samples of 3,686 Japanese of varying ages in five districts throughout Japan. They collected the hair samples at beauty salons, barbershops, and primary schools in each district. Each person donating a hair sample completed questionnaires about their age, gender, amount and species of fish usually eaten, if their hair was dyed, and if they used a permanent wave on their hair. The scientists used this information to study the blood mercury of different subpopulations of Japanese citizens by their gender and the region of Japan where they live. The scientists also studied the source(s) of the mercury exposure.
  
• Two-thirds of Japanese women of childbearing age had levels of mercury greater than the Environmental Protection Agency (EPA) recommended maximum level. About 2% of Japanese women had even higher levels of mercury.
  
• The effects of artificial waving on hair mercury concentrations change the results of the mercury levels reported because the individual hair mercury levels may be reduced by as much as one-half after the treatment(s).
  
• This study used volunteers instead of the usually required random sampling of study participants. Random sampling allows the reader to have more confidence that the study results are accurate and reliable.
  
• Average mercury levels in the hair of these Japanese subpopulations are estimated to be relatively higher than the average mercury levels observed in several Western countries.
  
• This statistical study found a significant relation of mercury levels with age, gender, amount of fish eaten each day, the use of permanent waving in the hair, and living in a certain region of Japan.
  
• A large proportion of the Japanese population is exposed to methylmercury through the daily intake of fish and/or shellfish at amounts greater than the EPA methylmercury reference dose. These scientists believe that this does not necessarily mean that these Japanese peoples are exposed to methylmercury levels that may harm their unborn children.
  
• These scientists reported that 0.4% of Japanese women of childbearing age had mercury levels that could put an unborn infant at risk. The scientists stated that they believed this particular small group of Japanese women of childbearing age may have to change the amount and/or types of fish they eat when these particular women are pregnant.

A Bottom Line:
Although this paper suggests that many Japanese are exposed to levels of methylmercury greater than the EPA recommended maximum level of methylmercury by eating fish and/or shellfish every day, these Japanese women may not be exposed to methylmercury levels that will harm their unborn infants.

Find This Scientific Paper for Your Review:
Current Hair Mercury Levels in Japanese: Survey in Five Districts. Tohoku Journal of Experimental Medicine (Tohoku J. Exp. Med.) Vol. 99, pp.161-169. 2003.