Environmental exposure to lead and cadmium and hearing loss in Chinese adults: A case-control study

PLoS One. 2020 May 20;15(5):e0233165. doi: 10.1371/journal.pone.0233165. eCollection 2020.

Abstract

Hearing loss is the second most common nonfatal problem affecting the Chinese population. Historical studies have suggested an association between exposure to heavy metals, such as cadmium and lead, and hearing loss. Few studies have investigated this relationship in the general population in China. We conducted a case-control study with 1008 pairs of participants from a cross-sectional epidemiological survey conducted in Zhejiang Province. A self-designed questionnaire was adopted to collect information on demographics, chronic diseases, lifestyles and environmental noise. Pure-tone averages of hearing thresholds at frequencies of 0.5, 1, 2, and 4 kHz were computed. Blood lead and cadmium levels were analyzed with an atomic absorption spectrometer. After adjusting for all other potential confounding factors, compared with the lowest blood cadmium quartile (0.00-0.53 μg/L), blood cadmium quartile 2 (0.54-0.92 μg/L), quartile 3 (0.93-1.62 μg/L) and quartile 4 (1.63-57.81 μg/L) exhibited significantly elevated risks for hearing loss, with odds ratios of 1.932 (95% CI: 1.356-2.751), 2.036 (95% CI: 1.423-2.914) and 1.495 (95% CI: 1.048-2.133), respectively (P-trend<0.001). However, an association of lead with hearing loss was not found. Young age (less than 60 years), male sex and current smoking were associated with increased blood cadmium concentration. Additionally, a positive association between blood cadmium and lead concentrations was found. Therefore, we conclude that exposure to environmental cadmium may be a risk factor for hearing loss among the general population in China.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Asian People
  • Cadmium / toxicity*
  • China / epidemiology
  • Environmental Exposure / adverse effects*
  • Female
  • Hearing Loss* / blood
  • Hearing Loss* / chemically induced
  • Hearing Loss* / epidemiology
  • Humans
  • Lead / toxicity*
  • Male
  • Middle Aged
  • Sex Factors
  • Surveys and Questionnaires*

Substances

  • Cadmium
  • Lead

Grants and funding

Liang-Wen Xu obtained the Zhejiang Key Research and Development Program (no. 2015C03050) funded by Science Technology Department of Zhejiang Province (http://www.zjkjt.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Lei Yang obtained the Major Scientific and Technological Innovation Projects of Hangzhou (no. 20152013A01) funded by Science and Technology Bureau of Hangzhou (http://kj.hangzhou.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Da-Hui Wang obtained the Program (Y201533217) funded by The Education of Zhejiang Province. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.