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

MERCURY 265
2. HEALTH EFFECTS
directly toxic to the respiratory system. Based on these results, it would appear that acute inhalation exposure
of humans to high levels of metallic mercury may result in pulmonary effects.
Cardiovascular Effects. The evidence from clinical, occupational, and general population studies suggests
that inhalation of metallic mercury may affect the cardiovascular system in humans, producing elevations in
blood pressure and/or heart rate (Aronow et al. 1990; Bluhm et al. 1992a; Campbell 1948; Fagala and Wigg
1992; Foulds et al. 1987; Friberg et al. 1953; Haddad and Sternberg 1963; Hallee 1969; Jaffe et al. 1983;
Karpathios et al. 1991; Siblerud 1990; Smith et al. 1970; Snodgrass et al. 1981; Soni et al. 1992; Taueg et al.
1992; Teng and Brennan 1959). Studies of workers chronically exposed to elemental mercury vapor have
shown increased incidences of palpitations (Piikivi 1989), high incidences of hypertension (Vroom and Greer
1972), and increased likelihood of death due to ischemic heart and cerebrovascular disease (Barregard et al.
1990). Of particular interest is the study showing slightly higher blood pressure in persons with dental
amalgams than in those with no mercury-containing amalgams (Siblerud 1990). Less information is available
regarding inhalation of organic mercury, but one study showed elevated blood pressure in two men
occupationally exposed to methylmercury compounds (Hook et al. 1954). Electrocardiographic abnormalities
(ventricular ectopic beats, prolongation of the Q–T interval, S–T segment depression, and T-wave inversion)
were reported in persons who ate foods contaminated with ethylmercury compounds or who ingested a large
dose of mercuric chloride (Chugh et al. 1978; Cinca et al. 1979; Jalili and Abbasi 1961). It is unclear whether
these electrocardiographic abnormalities were the result of direct cardiac toxicity or whether they were
secondary to other toxicity.
A number of the above cases of mercury-related tachycardia and elevated blood pressure in children inhaling
metallic mercury vapors (Aronow et al. 1990; Fagala and Wigg 1992; Foulds et al. 1987; Karpathios et al.
1991) are associated with acrodynia, a nonallergic hypersensitive reaction in children to mercury exposure.
Similar elevations in heart rate and blood pressure have been reported in children ingesting mercurous
chloride (calomel)-containing medications and in children dermally exposed to ammoniated mercury-
containing ointments or diapers that had been rinsed in a mercuric chloride-containing solution (Warkany and
Hubbard 1953).
Limited animal data are available regarding inhalation exposure to mercury, but studies indicate that mercury
may have a toxic effect on the heart. Effects ranging from mild pathological changes to marked cellular
degeneration of heart tissue were exhibited in rabbits inhaling 0.86–28.8 mg/m 3 mercury vapor for