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 are a in Poland. Blood lead was determined using inductively coupled plasma mas s spectrometry, with appropriate quality control. The concentrations of lea d in blood (B-Pb) in 155 children, aged 4-14, ranged from 19 to 281 mu g/L (0.09 to 1.4 mu mol/L), with a median of 72 mu g/L (0.34 mu mol/L). The hea ring thresholds increased significantly with increasing blood lead levels a t all investigated frequencies (0.5, 1, 2, 4, 6, and 8 kHz). The relationsh ip also remained significant for B-Pb below 100 mu g/L (0.48 mu mol/L; n=10 7). The brainstem auditory evoked potential latency of wave I was significa ntly increased (also after adjustment for age) in the group of children wit h the highest blood lead levels (B-Pb above 100 mu g/L, 0.48 mu mol/L; n = 51), compared to the group with the lowest ones (B-Pb below 46 mu g/L, 0.22 mu mol/L; n = 51). The audiometric results clearly indicate that auditory function in children is impaired at a blood lead concentration even below 1 00 mu g/L (0.5 mu mol/L). (C) 1999 Academic Press.