Mercury Poisoning
Occupational Sources Manufacture of electric equipment, ammunitions, amalgams, felt making, disinfectants coal plants - emit approximately half of atmospheric mercury gold production, non-ferrous metal production, cement production, waste disposal, crematoria, caustic soda production, pig iron and steel production, mercury production (mostly for batteries)
Mercury and its compounds are commonly used in chemical laboratories, hospitals, dental clinics, and facilities involved in the production of items such as fluorescent light bulbs, batteries, and explosives. Common items that may contain mercury Flourescent bulbs Mercury thermometers Watch batteries thermostats
Exposure Inhalation of Mercury Vapors - 80% Most dangerous (lungs-blood- kidneys&brain) Oral ingestion of liquid metallic mercury, subcutaneous routes Urinary and fecal routes - excretory pathways
Toxic Dose World Health Organization reports that the amount of mercury-absorbed daily by the average human body is ug Uptake of >100ug can be extremely lethal
Mechanism of Toxicity Severe imbalance in the ratio of active to inactive glutathione, the body's most important tool for detoxifying and excreting metals Causes Neurological impairments particularly CNS affectation
Common Acute and Chronic Effects and Confirmatory Diagnostic Test
Fulminant Symptoms Acute /sudden/ may be intense Rarely causes systemic poisoning Dermatitis Sensitization Stomatitis Conjunctivitis
Initial Exposure to High Concentrations Metal Fume Fever Fatigue Fever Chills Respiratory: cough, SOB, tightness, burning of chest and lung inflammation Mercury splashes
Occupational Exposure levels: 1-44 mg/m3 (4 to 8 hours) Chest pain Cough Hemoptysis impaired lung function Lung inflammation Pulmonary edema
Chronic Symptoms Insidious/Gradual onset Classic triad of elementary mercury poisoning Oral manifestations: gingivitis, salivation, stomatitis Intentional tremors Erethism (neurobehavioral changes characterized by anxiety, depression, irritability, emotional instability and regressive behavior; abnormal irritability or sensitivity of an organ upon stimulation)
Other Signs Blue line in gums Metallic fetid breath Metallic or sweet taste Tremors of facial and hand muscles Loss of memory Depression Insomnia Hyperactive knee jerks Anxiety and irritability
Confirmatory Diagnostic Test 1. Urine Mercury level is above 50 mcg/dL – tentative maximum permissible concentration 2. Whole blood levels: 10 mcg/dL (methylmercury) 2 mcg/dL (inorganic Hg)
Specific Management/Antidote
Specific Management Decontamination requires removal of clothes, washing skin with soap and water, and flushing the eyes with saline solution as needed. Inorganic ingestion such as mercuric chloride should be approached as the ingestion of any other serious substance that causes corosion. Immediate chelation therapy is the standard of care
Treatment/Antidotes DMSA Forms an inactive complex with mercury Chelation for acute inorganic mercury poisoning to be excreted Penicillamine Increases the excretion of mercury after acute exposure to mercury vapor
Preventive Measures (Primary and Secondary)
Primary prevention Personal Protective Equipment Use masks, respirators, and gloves Engineering controls Proper ventilation via exhaust systems Good housekeeping Handle under fume hood to eliminate vapors Proper container Avoid spillage, proper waste disposal Proper hygiene
Primary Prevention Engineering Controls Proper ventilation via exhaust systems Handle under fume hood to eliminate vapors Proper container (airtight) Administrative Controls Good housekeeping proper waste disposal Health education and Proper hygiene Personal Protective Equipment Mask, respirators, gloves
Secondary Prevention Recognize early clinical manifestations to avoid serious developments Application of physiological methods of measurement Pre-employment and periodic examination and records Regular monthly medical evaluations with emphasis to blood level monitoring
Secondary Prevention Urine mercury over 50mcg/dL Blood levels 10mcg/dL