Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX6-57
Table AX6-3.6 (cont’d). Evoked Potentials and Occupational Lead Exposure in Adults
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
Europe (cont’d)
Discalzi et al. (1993)
Italy
Latin America
Counter and Buchanan
(2002)
Ecuador
Asia
Holdstein et al. (1986)
Israel
22 battery storage workers, mean age 35 yrs and 22
control group, age and sex matched, with normal
hearing had BAEPs recorded. Latencies I and V and Pb
exposure examined by ANOVA after stratifying blood
Pb.
30 Pb-glazing workers, median age 35 yrs, had puretone
thresholds and BAEPs performed. Regression
analyses examined relations between auditory outcomes
and blood Pb.
20 adults and 8 children (mean age 27 yrs, range 8 - 56
yrs) accidentally exposed to Pb through food until one yr
prior to measurement of BAEP.
Mean blood Pb 48µg/dL Interpeak latency I-V was significantly prolonged in Pb
exposed workers (p = 0.001). No significant associations by
linear regression between I-V and Pb exposure. Stratifying
Pb exposed workers by blood Pb 50 µg/dL found I-V
interpeak latency significantly prolonged (p = 0.03) in
subgroup with higher blood Pb.
Mean blood Pb 45 µg/dL
(range 11 to 80 µg/dL)
Mean blood Pb
Adult 31 µg/dL
Children 22 µg/dL
10 mo avg blood Pb Adults
43 µg/dL
Children 36 µg/dL
Sixty percent of the men and 20 percent of the women had
abnormal high-frequency thresholds, however there was no
significant relationship with blood Pb and pure tone threshold
at all frequencies. Analysis of BAEPs found agreement
between latencies for Waves I, III and V and peripheral
hearing status. Interpeak latencies were within normal limits
but no analysis provided with Pb exposure. Workers lived in
a Pb contaminated environment from discarded Pb-acid
storage batteries. Therefore a measure of chronic Pb
exposure may have been more appropriate.
In adults, latencies I, III and I-III and I-V interpeak intervals
were significantly longer than the control group (p < 0.05).
When group stratified by 10 mo avg blood Pb I-III interpeak
interval was longer in the high group. Age and blood Pb
were not studied due to few subjects. The I-III interpeak
interval reflects transmission in the lower brainstem and
VIIIth nerve.