Highest levels ever seen or just a typo?

Posted by Michele A. La Merrill, Ph.D. at Aug 26, 2009 11:50 AM |

China Daily articles that report milligrams – not micrograms – of lead in children's blood are most likely a translation problem.

Hu Yongqi and Tan from China Daily report that 300 children suffering from lead poisoning in China will be treated to reduce their high levels. The story is one of many following the lead poisoning incident affecting hundreds of Chinese children. 

The reporters state that “the normal lead content in blood ranges from zero to 100 mg per liter and health is affected if the content is over 200 mg per liter.”
 
The reported blood levels in the children are misleading. In science, "mg" universally represents milligrams. But, blood lead levels are reported as micrograms, concentrations that are 100 (Correction, 8/28/09: 1,000) times less than milligrams. Micrograms are abbreviated using the greek letter "mu", sometimes reported as ug, because the "u" looks a little like mu. 
 
If the China Daily article is reporting the correct blood levels in kids, that is a lot of lead. In this case, 200 mg per liter is equal to 20,000 micrograms per deciliter. Dr. Perry Sheffield, a pediatrician who specializes in children's environmental health, tells EHN by e-mail that she would expect "obtundation, coma, and likely death well before this level was reached." [Diminished] (Correction, 8-31-09) mental capacity ("obtundation" in medical language) is expected when children suffer lead poisoning, but coma and death are very unusual.
 
To put the level of lead needed to poison children in context, consider that the US Centers for Disease Control and Prevention define an "elevated blood lead level" in children as greater than 10 micrograms of lead per deciliter of blood.  
 
But recent research suggests that even blood lead levels below 10 micrograms per deciliter may not be harmless, especially to children's health. The lower levels are associated with the same health effects as higher levels: decreased IQ, decreased concentration and decreased neurobehavioral development in children.
 
Possible interpretations for the gaffe are that Hu Yongqi and Tan Yingzi have misreported the normal blood lead levels, or that there is a font translation issue. To avoid micrograms being read as “mg” for milligrams, it would best for journalists to spell out the words.