砷之生物暴露指標探討-職業性無機砷與飲食性有機砷共同暴露影響之評估

It is an important measure to establish a
reliable biological exposure index to monitor
and, accordingly, to prevent the potential
inorganic exposure at work. The present
study was therefore performed to evaluate
the extent of interference and the reliability
of urinary arsenic species as biological
exposure index by comparing the effects of
co-existing field inorganic arsenic exposure
and dietary organic arsenic exposure. Study
subjects included 26 preventive maintenance
engineers and industrial hygiene engineers.
Their work history and dietary seafood
intakes prior to the urine sample collection
were used to compare with the urinary
arsenic species distribution. Sample collected
included seafoods from the study factory’s
kitchen, study subjects’ urine, and air
samples of the workplace. All samples,
except air samples, were analyzed with the
HPLC-ICP-MS for As 3+ 、As 5+ 、
monomethylarsonic acid, dimethylarsinic
acid, Arsenocholine(AsC)、
Arsenobetaine(AsB)、Arsenosugar(AsS)及
trimethylarsinic oxide(TMAO). Results show
that the highest arsenic species was found for
AsB in crab, up to 39.3ug/g dry. Most of the
air sample could not be detected for arsenic,
< 0.2 ug/m 3 . High urinary arsenic species
were found for AsB and DMA, along with
huge variation, and the highest one was AsB
of about 200 ug/L. And, they were found
highly associated with the uptake of certain
seafood intakes (p<0.0001). With respect to
urinary MMA, it changed little even after the
study subjects have ingested seafoods.
Although both the levels of MMA and As 3+
were very low, they were highly correlated,
either in terms of the concentration itself or
their percentages in the sum-up urinary
arsenic species (p<0.0001 and 0.020,
respectively). Besides, even though the
inorganic arsenic exposure was limited at
workplace, conducting preventative
maintenance work was still demonstrated
associated with the urinary MMA levels
(p<0.05). This study therefore concluded that,
compared to the processed seafood, raw
seafood, in daily diets, contributed much
more to the urinary arsenic species. On the
other hand, urinary MMA still could be a
good indicator for inorganic arsenic exposure
even at low level inorganic arsenic exposure
and with high interfering influence of dietary
organic arsenic uptake.