We’ve long known that there is some association between lead exposure and hearing function (peripheral and central) in adults. The effects of heavy metals on adult hearing as a result of workplace exposure have been studied fairly extensively. An up to date review of 49 studies was published last year (Castallanos & Fuente, 2016). Less is known about the effect of heavy metal exposure on children’s peripheral and central auditory function.
A 2011 study by from Massachusetts Eye and Ear Infirmary indicates that “teens exposed to higher-than-normal levels of lead are more likely to have trouble hearing.” A review of the study has a headline designed to alarm: High Lead Exposure Linked to Hearing Loss in Youth.
But don’t be alarmed. Just register the already-known fact that you want to keep your kids (and yourself) clear of lead exposure. Here’s a more sedate, albeit sobering, take on the study findings:
- Only 1 in 20 adolescents had high lead concentrations (2 mcg/dL or higher) that might be linked to hearing loss.
- Lead levels are lower overall than they were several decades ago.
- Almost one third of the adolescents with those high levels of lead had some degree of hearing loss (>15 dB threshold(s).
- The current US standard for acceptable blood level in children is < 10 mcg/dL, which is 5 times higher than the “high” level defined in this study.
Take Home for Audiologists
“…audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals.” (Castellanos & Fuente, 2016)
- Castellanos M-J & Fuente A. The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review. Int J Environ Res Public Health. 2016 Dec; 13(12): 1223. Published online 2016 Dec 9. doi: 10.3390/ijerph13121223 PMCID: PMC5201364
- Shargorodsky J et al. Heavy metals exposure and hearing loss in US adolescents. Arch Otolaryngol Head Neck Surg. 2011 Dec;137(12):1183-9. doi: 10.1001/archoto.2011.202.