Elevated lead levels as a risk factor for pediatric sensorineural hearing loss

Despite legislation banning the use of lead paint in the United States in 1978, pediatric lead exposure still occurs. In 2021, the CDC reduced the reference value for blood lead levels to 3.5ug/dl noting even low levels of lead can be harmful. The neurologic consequences of pediatric lead exposure are well documented. Few studies have linked lead exposure to hearing loss in children.

To identify a relationship between pediatric lead exposure and sensorineural hearing loss.

The TriNetx Analytics Network, a federated health research network that aggregates the de-identified electronic health record data of over 78 million patients across the United States, was queried for patients 18 years old or younger with a laboratory result of blood lead levels ≥3.5 μg/dL. Patients with blood lead levels <3.5ug/dL were evaluated as a control group. Patients in these groups with diagnosis of sensorineural hearing loss were recorded. Patients with diagnoses of congenital cytomegalovirus, congenital, inner ear malformations, and noise induced hearing loss were excluded from analysis.

Out of 15,820 children 18 years old or younger with elevated blood lead levels, 2.83 % had a diagnosis of sensorineural hearing loss. Out of 120,460 children 18 years or younger without elevated blood lead levels, 2.32 % had a diagnosis of sensorineural hearing loss. The relative risk for sensorineural hearing loss in children with elevated blood lead levels was 1.22 (95 % CI: 1.21-1.23, p = 0.005).

Pediatric patients with elevated blood lead levels ≥3.5 μg/dL were 1.22 times as likely to have sensorineural hearing loss than those without. This study is the largest to examine the relationship between lead exposure and SNHL according to the CDC's newest reference value. Clinicians should be aware of this relationship and have a low threshold for audiologic referral.