Boston — A study published in the December 2011 issue of the Archives of Otolaryngology – Head & Neck Surgery indicates that blood lead levels that are below the current recommended action level are associated with substantially increased odds of high-frequency hearing loss.
According to the abstract, the researchers evaluated the cross-sectional associations between blood lead, blood mercury, and urinary cadmium and arsenic levels and audiometrically determined hearing loss in participants aged 12 to 19 years in the 2005-2008 National Health and Nutrition Examination Survey.
Of this group, there were 2,535 individuals available for analysis of blood lead and mercury levels, 878 for urinary cadmium levels, and 875 for urinary arsenic levels.
The results showed that a blood lead level greater than or equal to 2 µg/dL compared with less than 1 µg/dL was associated with increased odds of high-frequency hearing loss.
In addition, those in the highest quartile of urinary cadmium levels had significantly higher odds of low-frequency hearing loss than those in the lowest quartile.
However, there was no overall association between quartiles of blood mercury or urinary arsenic levels and hearing loss.
The authors’ overall conclusion is that blood lead levels that are “well below the current recommended action level” are associated with substantially increased odds of high-frequency hearing loss.