HIGH LEAD-EXPOSURE AND AUDITORY SENSORY-NEURAL FUNCTION IN ANDEAN CHILDREN

We investigated blood lead (B-Pb) and mercury (B-Hg) levels and audito ry sensory-neural function in 62 Andean school chiidren living in Pb-c ontaminated area of Ecuador and 14 children in a neighboring gold mini ng area with no known Pb exposure. The median B-Pb level for 62. child ren in the Pb-exposed group was 52.6 mu g/dl (range 9.9-110.0 mu g/dl) compared with 6.4 mu g/dl (range 3.9-12.0 mu g/dl) for the children i n the non-Pb exposed group; the differences were statistically signifi cant (p<0.001). Auditory thresholds for the Pb-exposed group were norm al at the pure tone frequencies of 0.25-8 kHz over the entire range of B-Pb levels. Auditory brain stem response tests in seven children wit h high B-Pb levels showed normal absolute peak and interpeak latencies . The median B-Hg levels were 0.16 mu g/dl (range 0.04-0.56 mu g/dl) f or children in the Pb-exposed group and 0.22 mu g/dl (range 0.1-0.44 m u g/dl) for children in the non-Pb exposed gold mining area, and showe d no significant relationship to auditory function.