Elemental mercury exposure: an evidence-based consensus guideline for out-of-hospital management

The objective of this guideline is to assist poison center personnel in the out-of-hospital triage and initial management of patients with suspected exposures to elemental mercury. An evidence-based expert consensus process was used to create this guideline. It is based on an assessment of current scientific and clinical information. The panel recognizes that specific patient care decisions may be at variance with this guideline and are the prerogative of the patient and health professionals providing care. The grade of recommendation is in parentheses.

1) Patients with exposure due to suspected self-harm, abuse, misuse, or potentially malicious administration should be referred to an emergency department immediately regardless of the exposure reported (Grade D). 2) Patients with symptoms of acute elemental mercury poisoning (e.g., cough, dyspnea, chest pain) should be referred immediately to an emergency department for evaluation regardless of the reported dose. Patients with symptoms of chronic toxicity (rash, tremor, weight loss, etc.) should be referred for healthcare evaluation, the timing and location of which is guided by the severity of illness and circumstances of the exposure (Grade C). 3) If the elemental mercury was recently heated (e.g., from stove top, oven, furnace) in an enclosed area, all people within the exposure area should be evaluated at a healthcare facility due to the high risk of toxicity (Grade C). 4) If the elemental mercury was vacuumed or swept with a broom, the health department should be contacted to perform an environmental assessment for mercury contamination. Consider healthcare referral for those exposed to documented high air mercury concentrations (Grade C). 5) Patients ingesting more mercury than in a household fever thermometer or those with abdominal pain after ingestion should be referred to an emergency department for evaluation (Grade C). Do not induce emesis or administer activated charcoal. 6) Asymptomatic patients with brief, unintentional, low-dose vapor exposures can be observed at home. Asymptomatic patients can be evaluated as non-urgent outpatients if there is concern for exposures to high doses (e.g., more than contained in a thermometer) or for chronic duration (Grade D). 7) Pregnant patients unintentionally exposed to elemental mercury and who are asymptomatic should be evaluated by their obstetrician or primary care provider as an outpatient. Immediate referral to an ED is not required (Grade D). 8) Patients with elemental mercury deposited or injected into soft tissue should be referred for evaluation of surgical removal (Grade C). 9) All elemental mercury spills should be properly cleaned up, including the small amount of mercury from a broken thermometer. Brooms and vacuum cleaners should not be used to clean up elemental mercury. The clean-up of any spill larger than a broken thermometer should be performed by a professional company, state health department, or the EPA. Detailed instructions are provided on the EPA website: www.epa.gov/epaoswer/hazwaste/mercury/faq/spills.htm (Grade D). 10) Patients with dermal exposures should remove all jewelry and wash the affected area with mild soap and water. Remove all contaminated clothing and place these items in a sealed plastic double-bag for proper disposal (Grade D). 11) Do not discard elemental mercury in household trash, plumbing drains, or sewer systems. Consult local authorities for the proper disposal of low-level elemental mercury-contaminated household items and thermometers (Grade D).