Mercury exposure in a residential community - Florida, 1994

Morbidity and Mortality Weekly Report, June 16, 1995

(*)Of 564 cases of known age, 139 (25%) were reported among children less than 5 years of age.

([dagger])Updated quarterly from reports to the Division of Sexually Transmitted Diseases and HIV Prevention, National Center for Prevention Services. First quarter data not yet available.

-: no reported cases

Reported by: JM Malecki, MD, Health and Rehabilitative Svcs/Palm Beach County Public Health Unit, R Hopkins, MD, State Epidemiologist, State of Florida Dept of Environmental Protection. U.S. Environmental Protection Agency. Air Pollution and Respiratory Health Br, National Center for Environmental Health, CDC.

Editorial Note: Most poisonings associated with exposure to elemental mercury occur in occupational settings, and reports of nonoccupational elemental mercury vapor poisonings are rare, especially in community-based settings (1)(2). The exposures described in this report primarily affected homes and schools.

Inorganic mercury is a heavy, silver-white metal that is liquid at room temperature. The vapor pressure of mercury is high compared with other metals, creating the continual hazard of airborne exposure to mercury vapor, which is odorless and colorless. Mercury is absorbed into the blood following inhalation and is then transported to the brain and other areas of the nervous system and to all other tissues. Most elemental mercury is excreted unchanged in feces.

The development of clinical manifestations as the result of inhalation of vapor is related to several factors, including the concentration of vaporized mercury length of exposure, and individual susceptibility (2)(3). Acute exposure to elemental mercury produces symptoms of metallic taste, burning, irritation, salivation, vomiting, diarrhea, upper gastrointestinal tract edema, abdominal pain, and hemorrhage (4). Symptoms of high levels of exposure usually begin abruptly and include fever, chills, malaise, nausea, coughing, shortness of breath, chest pain and tightness; the clinical course may progress to pulmonary edema and death (5). In comparison, chronic inorganic mercury poisoning can result in intention tremor, memory loss, insomnia, depression, irritability, excessive shyness, emotional instability, delirium, and acrodynia and may result in a neurologic syndrome known as "mad hatter syndrome" (2)(3)(4)(5).

The risks associated with mercury exposure are especially increased for children because mercury vapor is dense and settles (2) and because children may be active on the floor or playing in dirt. In addition, because of lipid solubility, mercury crosses the placenta and is excreted in breast milk and, therefore, is a potential health hazard for unborn children and breastfeeding infants (6)(7).

Elemental mercury is still widely used in industry for the manufacture of thermometers, barometers, vacuum pumps, and electrical components and may be present in household products such as cleaning solutions and adhesives (2)(5). Small amounts of mercury, such as from a broken thermometer, can be cleaned up by spraying the mercury gently with hairspray or dusting with an absorbent such as powdered sulfur and sweeping up the mercury and absorbent with a wisk broom. After cleaning the spill, the broom should be securely bagged and discarded (8). Any person who discovers a large quantity of mercury should immediately contact the local poison-control center or health department.