| Summary: | 碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 86 === Most occupational lead exposure studies gave priority to the pathway
of inhalation, and less focus on the route of ingestion. The present
study tried to apply dust loading on workers as indirect exposure index
, along with questionnaire interview, to evaluate the role of ingestion
in the exposure pathways of lead among workers of a lead battery factory
. The relationship of respirable and total lead concentrations was also
under investigation. Besides, further analysis on variance was conducted
to explore the comprehensive relationships among blood lead levels,
environmntal lead levels and the relevant exposure factors.
Study subjects included 18 male and 78 female workers from a lead
battery plant. Questionnaires were administered to these workers for
personal information collection, including basic demographic data, work
history, diet, and individual hygiene, etc. Personal sampling for respirable
air lead and body dust loading were conducted for each study subject. At
the same time, area samples were also collected for both respirable and
total lead at the specified sites. Environmental samples were analyzed
for lead with flame atomic absorption spectrometer or graphite furnace
atomic absorption spectrometer.
Results showed that the proportion of respirable lead to the total
lead amount was not very high. They were 38.1±20.3%, 35.5±23.9%, and
31.4±19.8% in combination, melting, and inserting areas, respectively.
This indicated that most air lead was in the airbone particulates with
size greater than 5μm. Results of total lead samples showed that average
lead concentrations were 0.122±0.068mg/m3 in combination area(n=42),
0.188±0.170mg/m3 in melting area(n=42), 0.264±0.543mg/m3 in inserting
area(n=20), and 0.105±0.117mg/m3 in checking area(n=21). All these lead
levels exceeded the PEL-TWA of 0.1mg/m3. Besides, the dust lead loading
on body surface(1.9*2.5cm2) were 212.0±194.7μg, 11.6±16.6μg, 6.2±8.7
μg, 2.4±8.1μg for glove (n=90), sleeve(n=94), hand(n=93), and cheek
(n=95), respectively, while that on lip sample (6.5*6.5cm2) was 0.18±0.28
μg(n=95). The average blood lead levels were 44.4±8.6μg/dl for male
workers(n=14) and 26.9±8.2μg/dl for female workers(n=77). Meanwhile,
air lead along with dust lead loading have been shown highly correlated
with the blood lead levels in a regression model(r2=0.133, p<0.05). Among
other exposure risk factors, work area, smoking, and eating in the work
area were also associated with the blood lead levels. Therefore, in
additional to air lead, more attention should be paid to lead dust loading
on the body in order to eliminate the lead exposure.
Keywords: blood lead, total lead, respirable lead, lead dust loading
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