Cent Eur J Public Health 1999, 7(2):80-82
Effect of environmental lead on hearing in women and children
- Institute of Public Health, Cluj-Napoca, Romania
The study of the effect of lead on hearing in women and children living in a town polluted with lead, revealed a lowering of the hearing threshold among the investigated groups. The women aged 20-50 years and children aged 7-12 years, never left the town. The lead concentration in the environment exceeded by 50-100 times normal values (0.0007 mg/m3/24 h). The subjects with a otological history were excluded from the study. The exposed groups comprised 77 women, 70 men (of the same age as women) and 152 children. The reference groups - 75 women and 150 children of the same age as the exposed ones - were selected from a non-polluted town, with an identical population density and car traffic. All groups were tested by air and bone conducted audiometry in a sound insulated chamber. The blood lead levels were used as exposure indicators. The biochemical tests performed in the exposed women and men revealed a blood lead level between 15 and 40 µg/dl. Blood lead levels were higher among children (between 20 and 70 µg/dl) because lead is more readily absorbed by the child organisms. The blood lead levels of both reference groups were under 15 µg/dl. The results showed a statistically significant decrease of the hearing threshold to 6 and 8 kHz in the exposed, as compared to the non-exposed women. No difference between lead-exposed women and men was found contrary to the noise exposure effect on sex - higher hearing loss in men. The mean magnitude of hearing threshold difference between the exposed and non-exposed women (10 and 9 dB for 6 and 8 kHz) was almost by 5 dB better than the values in children (15 and 14 dB for 6 and 8 kHz).
Zveřejněno: 1. červen 1999 Zobrazit citaci