You read that right — heavy metals not heavy metal.
A new study in the Archives of Otolaryngology—Head & Neck Surgery reports that:
A blood lead level greater than or equal to 2 μg/dL (to convert to micromoles per liter, multiply by 0.0483) compared with less than 1 μg/dL was associated with increased odds of high-frequency hearing loss (OR, 2.22; 95% CI, 1.39-3.56) [in adolescents]. Individuals in the highest quartile of urinary cadmium levels had significantly higher odds of low-frequency hearing loss than those in the lowest quartile (OR, 3.08; 95% CI, 1.02-9.25). There was no overall association between quartiles of blood mercury or urinary arsenic levels and hearing loss.
Fortunately the authors admit,
However, because of the crosssectional [i.e., statisical] methodology of this study, causality with respect to risk factors for hearing loss cannot be determined.
WHAT? WHAT? Could you repeat that.
However, because of the crosssectional [i.e., statisical] methodology of this study, causality with respect to risk factors for hearing loss cannot be determined.