Lead Exposure and Hearing Effects in Children in Katowice, Poland

The objective of the study was to investigate the relationship between lead exposure and hearing in children in the Katowice region, an industrial area in Poland. Blood lead was determined using inductively coupled plasma mass spectrometry, with appropriate quality control. The concentrations of lead in blood (B-Pb) in 155 children, aged 4–14, ranged from 19 to 281 μg/L (0.09 to 1.4 μmol/L), with a median of 72 μg/L (0.34 μmol/L). The hearing thresholds increased significantly with increasing blood lead levels at all investigated frequencies (0.5, 1, 2, 4, 6, and 8 kHz). The relationship also remained significant for B-Pb below 100 μg/L (0.48 μmol/L;n=107). The brainstem auditory evoked potential latency of wave I was significantly increased (also after adjustment for age) in the group of children with the highest blood lead levels (B-Pb above 100 μg/L, 0.48 μmol/L;n=51), compared to the group with the lowest ones (B-Pb below 46 μg/L, 0.22 μmol/L;n=51). The audiometric results clearly indicate that auditory function in children is impaired at a blood lead concentration even below 100 μg/L (0.5 μmol/L).