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

AX6-42
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
Europe (cont’d)
Stollery et al. (1991)
England
Stollery (1996)
England
Barth et al. (2002)
Austria
Seventy Pb-exposed workers, mean age
41(no SD) yrs, grouped by blood Pb
(40 µg/dL had impairments that correlated best with avg blood Pb
over the preceding 8 mos. Workers with blood Pb between 21 to
40 µg/dL had essentially no impairment.
Same as above Movement and decision slowing was correlated with blood Pb.
Slowed movement time was constant across response-stimulus
intervals in contrast to decision time that was increasingly affected by
Pb especially at the shortest response-stimulus intervals.
This supported the finding that decision gaps, central in origin, as
opposed to movement gaps are selectively affected by Pb exposure in
this population.
Pb workers
Mean (SD) blood Pb 31
(11.2) µg/dL
Mean (SD) IBL 384
(349.0) µg·yr/dL
Mean (SD) yrs employed
12 (9.0)
Controls
Mean (SD) blood Pb 4
(2.0) µg/dL
Significant differences were found for block design (p # 0.01), visual
recognition (p # 0.01) and Wisconsin card sorting (categories
p = 0.0005, total errors p = 0.0025, perseverations p = 0.001, loss of
sorting principle p = 0.003) but not SRT or digit symbol. In the
exposed group partial correlation adjusting for age found no
significant associations with IBL (n = 53). In the entire group the full
correlation was significant for blood Pb and Wisconsin card sorting,
block design and visual recognition (n = 100). Visuospatial abilities
and executive function were better predicted by blood Pb than
cumulative Pb exposure. It is unusual that a frontal lobe task is
associated with blood Pb when SRT and digit symbol sensitive to the
affects of Pb are not.