Environmental exposure to organochlorine pesticides and its association with the risk of hearing loss in the Chinese adult population: A case-control study.

Hearing loss is a common chronic sensory deficit that has become a major public health concern worldwide. Hearing loss is well documented to be induced by noise and ototoxic drugs, and the association of hearing loss with environmental pollutants has received increasing attention. Organochlorine pesticides (OCPs) are an important group of environmental pollutants that exist ubiquitously in the human body and continue to represent a significant environmental health concern. Our case-control study was performed to explore the association between serum levels of OCPs and the risk of hearing loss in China, including 87 case-control pairs. Serum concentrations of 15 OCPs were measured. Pearson's correlation analysis and principal component analysis of frequently detected (>80%) OCPs showed a different distribution pattern, indicating possible exposure sources/scenarios for the case-control adult population. A higher α-hexachlorocyclohexane (α-HCH) level was a risk factor for an increased prevalence of hearing loss. The risk of hearing loss was increased by approximately 5.25-fold in the highest tertile compared with the lowest tertile. Furthermore, a significant association of the α-HCH level with an increased hearing threshold was observed at mid/high frequencies. This study provided the first evidence indicating that exposure to α-HCH might be a potential risk factor for hearing loss.