revised final - Agency for Toxic Substances and Disease Registry ...

MERCURY 314
2. HEALTH EFFECTS
5–10% mercuric ammonium chloride had a mean mercury concentration of 109 µg/L, compared to 6 µg/L
for urine samples from women who had discontinued use and to 2 µg/L for women who had never used the
creams (Barr et al. 1973). Increased urinary excretion and blood levels of mercury were observed in
volunteers who used phenylmercuric borate solutions or lozenges intended for the treatment of mouth or
throat infections (Lauwerys et al. 1977). Swedes consuming fish contaminated with 0.3–7 mg Hg/kg (0.3­
7 ppm) had blood cell levels of total mercury ranging from 8 to 390 ng/g (Skerfving 1974). Long-term
exposure to methylmercury at 4 µg Hg/kg/day was associated with a mercury level in blood cells of
approximately 300 ng/g (Skerfving 1974). The steady-state concentration of methylmercury in blood may
be related to daily intake in the following equation (Task Group on Metal Accumulation 1973; WHO
1990):
C' f(d
b(V ' AD (AB (d
b(V
Where:
C = concentration in blood
f = fraction of the daily intake taken up by the blood
d = daily dietary intake
b = elimination constant
A D = percent of mercury intake in diet that is absorbed
A B = percent of the absorbed amount that enters the blood
V = volume of blood in the body
Hair is a biomarker of long-term exposure to methylmercury. Once mercury is incorporated into hair, it
remains unchanged (Clarkson et al. 1973; Nielsen and Andersen 1991a, 1991b). A number of studies have
examined the level of mercury in hair relative to the amount of fish consumed (see Table 2-10) (Airey
1983b; Haxton et al. 1979; Oskarsson et al. 1990; Sherlock et al. 1982). A fairly strong correlation has
been demonstrated by these studies between the amount of fish consumed, the level of mercury in the fish,
and the level of mercury in hair. Furthermore, the relationship between hair levels and blood levels has
been well studied (see Table 2-9) (Amin Zaki et al. 1976; Den Tonkelaar et al. 1974; Haxton et al. 1979;
Kershaw et al. 1980; Phelps et al. 1980; Sherlock et al. 1982; Skerfving 1974; Soria et al. 1992).
A number of studies report that hair mercury levels correlate with total intake levels and with organ-
specific levels of mercury. Suzuki et al. (1993) analyzed 46 human autopsies in Tokyo, Japan and
reported that hair mercury levels were highly significantly correlated with organ Hg levels in the
cerebrum, cerebellum, heart, spleen, liver, kidney cortex, and kidney medulla, when the total mercury or
methyl mercury value in the organ was compared with the hair total mercury or organic mercury,
respectively.