Despite the 1978 ban on lead-based paint for residential use, lead poisoning continues to be a serious public health threat, particularly for children because they are most susceptible to its effects.
In a new observational study, a pair of researchers at the San Francisco Veterans Affairs Medical Center and the University of California, San Francisco found that low levels of ascorbic acid (vitamin C) in the blood stream were associated with high blood levels of lead among Americans. The study's findings, which are published in the June 23 issue of the Journal of the American Medical Association (JAMA), also indicate that about half of one percent of all Americans (more than a million people) have elevated levels of lead in their blood.
According to the US Environmental Protection Agency, current studies suggest that the primary sources of lead exposure for most children are deteriorating lead-based paint, lead-contaminated dust, and lead-contaminated residential soil. Prior to 1978, lead was commonly used as a coloring agent and a stabilizer in paint.
"Vitamin C levels are an important independent correlate of blood lead levels among Americans," says Joel Simon, MD, MPH, SFVAMC staff physician and UCSF assistant professor of medicine, epidemiology & biostatistics. "To our knowledge, this report is the first population-based study to establish such an association. If a causal relation is confirmed, increased consumption of ascorbic acid may have public health implications for the prevention of lead toxicity."
The correlation between levels of vitamin C and blood lead levels is
supported by the findings of a recent small clinical trial, conducted at the
University of Texas Medical Branch in Galveston, that found that 1000mg vitamin
C supplements decreased the blood lead levels of heavy smokers. Because smoking
decreases the absorption and increases the metabolism of vitamin C, higher
dietary vitamin C intake levels are recommended.
Contact: James Larkin
University of California - San Francisco