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

MERCURY 428
5. POTENTIAL FOR HUMAN EXPOSURE
respectively. The control plants (no mercury compounds added to the sediments) contained 0.3 ppm
mercury. It is clear from this experiment that organomercury compounds may accumulate significantly
in the above-ground parts of some macrophytes. Mortimer (1985) found that although E. densa shoots
had lower total mercury contents than roots, with 32% of the mercury in the shoots in the form of
methylmercury, compared to only 10% in the roots.
Grasses sampled downwind of a municipal waste incinerator contained up to 0.20 µg/g (ppm) of
mercury, with concentrations decreasing with increasing distance from the facility (Bache et al. 1991).
Background mercury levels in vegetation were usually below 0.1 µg/g (ppm) dry weight (Lindqvist
1991e); however, mushrooms collected 1 km from a lead smelter in Czechoslovakia contained between
0.3 and 12 mg/kg (ppm) dry weight (Kalac et al. 1991).
Consumer and Medicinal Products. Various consumer and medicinal products contain mercury
or mercury compounds (i.e., skin lightening creams and soaps, herbal remedies, laxatives, tattooing
dyes, fingerpaints, artists paints, and make-up paints) (Barr et al. 1973; Dyall-Smith and Scurry 1990;
Lauwerys et al. 1987; Rastogi 1992; Wendroff 1990).
Barr et al. (1973) reported elevated mercury levels in the blood of women using skin lightening creams,
although the mercury compound and concentrations in the skin cream were not determined. More recently,
Dyall-Smith and Scurry (1990) reported that one skin lightening cosmetic cream contained 17.5% mercuric
ammonium chloride. Lauwerys et al. (1987) reported a case of mercury poisoning in a 3-month-old infant
whose mother frequently used a skin lightening cream and soap containing inorganic mercury during her
pregnancy and during the 1-month lactation period following birth. However, the mercury concentration
and specific mercury compound in the cream and soap were not determined. Al-Saleh and Al-Doush
(1997) analyzed the inorganic mercury content of 38 skin lightening creams in Saudi Arabian markets. The
creams were manufactured in a variety countries, including India and Pakistan, other Arab countries,
Thailand, Taiwan, Indonesia, England and Germany. Almost 50% of the creams tested exceeded the
tolerance limit of 1 ppm. The mean concentration of mercury in the 38 creams was 994 ppm, with a range
of 0–5,650 ppm. It is not known whether any of these products are available in the United States.
Metallic mercury was also the source of two cases of mercury poisoning caused by the dermal application
of an over-the-counter anti-lice product (Bourgeois et al. 1986). The more severely poisoned individual
applied 30 g of ointment containing 9 g of metallic mercury (300,000 ppm) to his entire body. Wands et al.