Chemistry Reference
In-Depth Information
action level for manganese is 0.5 mg/L. With the estab-
lishment of the 0.5 mg/L action level, DHS recommends
follow-up monitoring for those water supply systems
that historically have shown manganese higher than
the 0.5 mg/L concentration, but that lack recent data
(USDHS, 2003).
In 1996, the WHO recommended 0.3 mg/m
3
as the
exposure limit for respirable manganese particles in
workplace air. Threshold limit value as time-weighted
average (TLV-TWA) set by American Conference of
Governmental Industrial Hygienists (ACGIH) in 1998
for manganese tetroxide compound and manganese
fume was 1 mg/m
3
. Currently, ACGIH for manganese
is 0.2 mg/m
3
TWA (TLV listed as manganese and inor-
ganic compounds, as Mn). The Occupational Safety
and Health Administration (OSHA) in 1998 proposed
0.2 mg/m
3
as PEL TWA for manganese, elemental and
inorganic compounds. Earlier OSHA's permissible
exposure limit value of 5 mg/m
3
is still valid for gen-
eral and construction industries and maritime, but as
ceiling value. Manganese cyclopentadienyl tricarbonyl
(MMT) as manganese (skin exposure) set by OSHA in
1998 was 0.1 mg/m
3
. The ACGIH value for MMT set in
1998 was 0.2 mg/m
3
, as manganese and, also 0.1 mg/
m
3
(skin).
(1990) and Davis and Greger (1992) reported serum
manganese concentrations in a group of healthy men
and women in Wisconsin of 1.06
g/L,
respectively. In healthy, unexposed people living in
the Lombardi region in northern Italy, manganese in
blood was 8.8 ± 0.2
µ
g/L and 0.86
µ
g/L
(Minoia
et al
., 1990). In woman, a hormonal infl uence
may cause variations in plasma manganese (Hagen-
feldt
et al
., 1973).
The concentration of manganese in blood and
serum seems to be fairly stable over long periods of
time (Cotzias
et al
., 1966; Mahoney
et al
., 1969). A slight
variation of blood manganese concentrations was
observed with somewhat lower levels during summer
and autumn months (Horiushi
et al
., 1967). Sullivan
et al
. (1979) found elevated manganese serum levels
in patients with congestive heart failure, infection,
and psychoses. Elevated manganese levels in blood to
approximately twice-normal values were found after
acute coronary inclusion (Newberne, 1973). Elevated
manganese concentrations in red cells but not in the
serum occur in patients with rheumatoid arthritis
(Cotzias
et al
., 1968).
The reported normal concentrations of manganese
in urine vary to a large extent. Data presented by
Buchet
et al
. (1976), Halls and Fell (1981), and Minoia
et al
. (1990) indicate that normally less than 1
µ
g/L and in serum 0.6 ± 0.014
µ
µ
g/L is
8 MANGANESE CONCENTRATIONS IN
BIOLOGICAL MEDIA AND BIOMARKERS
OF EXPOSURE AND EFFECTS
found.
As a group, workers exposed to a mean concen-
tration of 1 mg manganese/m
3
had higher levels of
manganese in the blood and urine than unexposed
controls (Roels
et al
., 1987). The group average levels in
blood seem to be related to manganese body burden,
whereas average urinary excretion levels are judged to
be most indicative of recent exposures. However, the
individual measurements do not correspond to indi-
vidual exposure.
There is only one study by Lucchini
et al
. (1995)
suggesting that blood and urine levels were corre-
lated with exposure levels on an individual basis.
In this study, a correlation was observed between a
cumulative exposure index (CEI) and manganese in
blood (MnB), and both MnB and CEI were associated
with neurobehavioral outcomes. Workers had been
tested during a month of layoff, and all the correla-
tions increased proportionally to the latency from the
exposure cessation. Mergler and Baldwin (1997) sug-
gested that in this study the correlation between CEI
and MnB and the dose-effect relationships were evi-
dent because MnB levels were not infl uenced by cur-
rent exposure and, therefore, they were better related
to the manganese levels accumulated in the body
storage deposits. This unique situation has not been
replied in the literature.
Manganese can be measured with good sensitivity
in biological fl uids and tissues, and levels in blood,
urine, feces, and hair have been investigated as pos-
sible biomarkers of exposure.
The reported normal concentrations of manganese
in blood, serum, and urine show a wide range. Data
by Muzzarelli and Rocketti (1975), Buchet
et al
. (1976),
Tsalev
et al
. (1977), and Zielhuis
et al
. (1978), determined
by electrothermal atomic absorption, indicate that the
average normal level in whole blood is 7-12
g/L. These
data agreed with data by Olehy
et al
. (1966), who used
neutron activation and found concentrations of 16
µ
µ
g/L
and 4.3
g/L in erythrocytes and plasma, respectively.
Assuming a hematocrit value of 45%, this would corre-
spond to 9.5
µ
g/L in whole blood. Cotzias
et al
. (1966)
found by neutron activation a mean normal level of
8.4
µ
g/L. Approximately 85% of blood manganese is in
the erythrocytes. In serum and plasma, average man-
ganese concentrations are reported to be 0.6-4.3
µ
g/L
as determined by neutron activation analysis (Cotzias
et al
., 1966; Hagenfeldt
et al
., 1973; Olehy
et al
., 1966)
and 0.6-1.0
µ
g/L as determined by electrothermal
atomic absorption (Halls and Fell, 1981). Greger
et al
.
µ
