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

AX6-34
Table AX6-3.2 (cont’d). Symptoms Associated with Occupational Lead Exposure in Adults
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
Latin America
Maizlish et al. (1995)
Venezuela
Asia
Schwartz et al.
(2001a)
Korea
Lee et al. (2000)
Korea
43 workers from a Pb smelter, mean age 34
(9) yrs and 47 nonexposed workers, mean
age 35 (11) yrs completed the profile of
mood states (POMS) questionnaire and a
questionnaire of symptoms of the central and
peripheral nervous system, and
gastrointestinal. Prevalence ratios used to
examine symptoms and Pb. ANCOVA and
linear regression adjusting for potential
confounders examined relationship of Pb
exposure and POMS.
803 Pb-exposed Korean workers, mean age
40 yrs completed the Center for
Epidemiologic Studies Depression Scale.
Linear regression examined for association
of CES-D and Pb biomarkers after adjusting
for the covariates.
95 Korean Pb exposed workers, mean age 43
yrs, completed questionnaire of Pb-related
symptoms present over last three mos.
Relationship between symptom score and
measures of Pb exposure assessed by linear
regression. Logistic regression use to model
presence or absence of symptoms for
gastrointestinal, neuromuscular, and general.
Pb workers
Mean (SD) blood Pb 43
(12.1) µg/dL
Mean (SD) peak blood Pb
60 (20.3) µg/dL
Mean (SD) TWA 48 (12.1)
µg/dL
Controls
Mean (SD) blood Pb 15 (6)
µg/dL
Mean (SD) peak blood Pb
15 (6) µg/dL
Mean (SD) TWA 15 (SD 6)
µg/dL
Mean (SD) blood Pb 32
(15.0) µg/dL
Mean (SD) tibia Pb 37
(40.3) µg/g bone mineral
DMSA-chelatable Pb Mean
(SD) 289 (167.7) µg
Mean (SD) ZPP 108 (60.6)
µg/dL
Mean (SD) ALAU3 (2.8)
mg/L
Mean(SD) blood Pb 45
(SD 9.3) µg/dL
Significantly increased relative risks found for difficulty
concentrating (RR = 1.8 [95% CI: 1.0, 3.1]), often being angry or
upset without reason (RR = 2.2 [95% CI: 1.2, 4.1]), feeling
abnormally tired (RR = 2.2 [95% CI: 0.9, 5.3]) and joint pain
(RR = 1.8 [95% CI: 1.0, 3.3]). The six subscales of the POMS were
not significantly different between the exposed and control groups.
However dose-related analysis found significantly poorer scores for
tension-anxiety and blood Pb (p = 0.009), hostility and blood Pb
(p = 0.01) and TWA (p = 0.04), and depression and blood Pb
(p = 0.003) and peak Pb (p = 0.003) and TWA (p = 0.004).
After adjustment for age, gender and education significant
associations found for CES-D and tibia Pb (∃ = 0.0021 [SE 0.0008];
p < 0.01) but not with blood Pb. This occupational Pb-exposed
populations had higher past Pb exposure compared to the current
mean blood Pb of 32 µg/dL.
Workers with DMSA-chelatable Pb above the median of 261 µg were
6.2 (95% CI: 2.4, 17.8) times more likely to have tingling or
numbness in their extremities, 3.3 (95% CI: 1.2, 10.5) times more
likely to experience muscle pain and 3.2 (95% CI: 1.3, 7.9) times
more likely to feel irritable. The workers with higher chelatable Pb
were 7.8 (95% CI: 2.8, 24.5) times more likely to experience
neuromuscular symptoms compared to workers with lower chelatable
Pb. In this study ZPP predicted weakness of ankle and wrist
(OR = 2.9 [95% CI: 1.1, 8.1]) and fatigue (OR = 2.9 [95% CI:
1.1, 8.7]) while ALAU predicted inability to sleep (OR = 5.4 [95%
CI: 1.2, 33.2]) and blood Pb was not significantly associated with any
symptoms. A measure of Pb in bioavailable storage pools was the
strongest predictor of symptoms particularly neuromuscular.