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

AX6-48
Table AX6-3.3 (cont’d). Neurobehavioral Effects Associated with Occupational Lead Exposure in Adults
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
Asia (cont’d)
Niu et al. (2000)
China
Boey and Jeyaratnam
(1988)
Singapore
44 Pb-exposed workers (17 men, 27 women)
from Pb printing houses, mean age 35 (4.9)
and education 9.3 (no SD) yrs and 34
controls (19 men and 15 women), mean age
33 (7.4) yrs and education 9.5 (no SD) yrs
completed the NCTB. ANCOVA controlling
for age, sex and education examined group
differences and linear regression for doseresponse
relationship.
49 Pb-exposed workers, mean age 26 (7.6)
yrs and 36 controls, mean age 30 (6.4) yrs
completed SRT and 8 psychological tests
covering attention, vigilance, visual-motor
speed, short-term memory, visuomotor
tracking, visual scanning, and manual
dexterity. Control group was matched for
education level. Discriminate analysis of
neurobehavioral tests performed to determine
which best discriminate the groups.
Pb workers
Mean (SD) blood Pb 29
(26.5) µg/dL
(8 workers blood Pb
exceeded 50 µg/dL)
Controls
Mean (SD) blood Pb 13
(9.9) µg/dL
(1 control blood Pb
exceeded 50 µg/dL)
Pb workers
Mean (SD) blood Pb 49
(15) µg/dL
Controls
Mean (SD) blood Pb 15
(3) µg/dL
SRT (F = 2.30, p < 0.05), digit symbol (F = 4.81, p < 0.01) pursuit
aiming # correct (F = 7.186, p < 0.01) and pursuit aiming total
(F = 6.576, p < 0.01) had significantly poorer performance compared
to controls. No repression analyses provided.
Six tests were significantly different between the two groups-Digit
Symbol, Bourdon-Wiersma, Trails A, Santa Ana dominant, Flicker
Fusion and SRT. The group of tests that best differentiates Pbexposed
workers from nonexposed workers were Simple Reaction
Time, Digit Symbol (WAIS) and Trail Making Test (Part A) with
long latency in reaction time contributing three times more to the
derived function than Digit Symbol (WAIS) or Trails A.