Lisa Quiggle Michigan Department of Community Health MERCURY Susan Smolinske, DMC Poison Control Center Jeff Kimble, USEPA OSC Grosse Isle MDCH Staff CREDITS: TOPICS Health Effects Exposuer Limits Laws Items containing mercury Clean up of small spills Public Health Particulars HEALTH EFFECTS MERCURY Ubiquitous metal Nonessential element Multiple physical states all forms can cause human toxicity Human exposure primarily from Elemental mercury - spills Organic mercury - seafood MERCURY EXPOSURE IN CHILDREN Organic mercury fish consumption tuna, fish sticks/sandwich in utero exposure Metallic mercury broken fever thermometers blood pressure monitors In past, schools number one site of spills (20%) MERCURY POISONING Can result from inhalation, ingestion, injection or dermal absorption Symptoms depend on type of exposure, type of Hg, and patient risk group Mercury is attracted to SH groups poison cellular membranes & enzymes 80% of elemental is absorbed by inhalation. Accumulates in cortex and cerebellum, then oxidized to Hg2+ where it is trapped. HISTORICAL SPILL The H.M.S Triumph salvaged elemental mercury (stored in kidskin bladders) from a wrecked Portuguese battleship Several tons of mercury were stored in food stores areas, bladders were ruptured and mercury hid throughout ship. Within 3 weeks, about 200 men developed tremors, mouth ulcers, drooling. Remedies (sulfur) were not effective. MAD AS A HATTER Fur was treated with mercury nitrate to make felt hats US Public Health Service banned mercury use for felting in 1941 Air concentrations 60 to 720 g/m 3 IN-UTERO METHYLMERCURY >90% of methylmercury is absorbed by ingestion Organic mercury crosses placenta and blood-brain barrier Mental retardation Developmental delay Abnormal movements Seizures Deafness Shaking Hypertension INHALATION OF MERCURY VAPOR: PEDIATRIC DOSE-RELATED HYPERSENSITIVITY Acrodynia or Pink Disease Traditionally mercuric chloride, but also elemental Red palms & soles; swelling of hands and feet; pain in extremities; itching with peeling of skin; hair loss; sweating with mouse odor; behavioral changes; muscle weakness; tremor; photophobia (sensitivity to light); increased HR and BP is a hallmark 1 in 500 children; 10% fatality rate In yo Michigan boy diagnosed, exposure interior latex paint banned in August 1990 Typically younger children, oldest case 15 year old ACRODYNIA PINK DISEASE THERMOMETER BREAKS AND HEALTH EFFECTS Simulated spills Breathing zone 25 g/m 3 Carpet 140 g/m 3 Actual spills g/m 3 or higher The lowest mercury levels associated with pediatric acrodynia (2-6 yrs) 4.2 g/m 3 CHRONIC EXPOSURE: MERCURY VAPOR (TOXICITY, NOT HYPERSENSITIVITY) Personality Changes Decreased vision/hearing Peripheral nerve damage (hands, feet) Hypertension Kidney damage INHALATION OF HEATED ELEMENTAL MERCURY 80% is absorbed by inhalation Chest tightness Lung failure Fever Weakness GI upset Gum inflammation Kidney failure (later) Neuropathy (later) INJECTION OF ELEMENTAL MERCURY Homicide, drug abuse, enhance athletic or sexual performance, self-mutilation, suicide IV Embolism Lung deposits, lung and kidney dysfunction, nerve damage, low sperm count EKG changes with atrial deposits INJECTION OF ELEMENTAL MERCURY Subcutaneous Redness, local tissue damage Remote deposits Fat necrosis, granuloma Prompt local excision can prevent toxicity Often minimal symptoms INGESTION OF METALLIC MERCURY Very poor absorption May collect in appendix no medical evaluation needed if small amount (thermometer contents) May be aspirated (inhaled into lungs) WE PLAYED WITH IT AGES AGO. WHY WORRY NOW? Acrodynia defined in 1950s from calomel (Hg 2 Cl 2 ) but elemental Hg cases only since 1988 Affected only 1 in 500 children, dose-related, depends on form of mercury; dont know incidence for elemental mercury Under-reporting is likely since testing is not routine Delay in diagnosis since mimics other illness All cases involved inadequate clean-up Chronic exposure takes weeks to months Decreased air exchanges in newer homes Infants (< 2 yrs) are more susceptible and retain higher percent of absorbed Hg in the brain. THIMEROSAL IN VACCINES Vaccines to 0.01% Thiosalicylate causes delayed hypersensitivity reactions Acute toxicity described with IV at 3 mg/kg from IVIG, HBIG, >100x vaccine dose Infants received up to 187 g during first 6 months Exceeds EPA guideline of 0.1 g/kg/day FDA/IOM found no evidence of harm from thimerosal in vaccines No longer in most vaccines! DENTAL AMALGAM 13 amalgams = 3 g/day 1/10 of average diet Need amalgams to produce toxic levels in urine g/L No health effects found in children (epidemiological studies) MERCURY LEVELS IN PEOPLE Blood mercury levels (recent exposure days) Normal (unexposed adults & children) - 3.5 g/L in pregnant women Neurotoxicity (tremors) g/L 5 of 14 youths playing with large amount had blood mercury 8 g /L on day two Usual half-life in blood is 2-5 days after vapor exposure Longer half-lives indicate ongoing exposure Urine mercury levels (chronic exposure 4 to 6 months) normal (in 95% of population) - 8 mcg/L on day two Usual half-life in blood is 2-5 days after vapor exposure Longer half-lives indicate ongoing exposure Selenium sulfide shampoo can decontaminate hair Urine is less reliable after acute vapor exposure Difficult to obtain 24 hr sample More useful in chronic exposures PRE-HOSPITAL CARE Victims of vapor exposure do not pose secondary contamination risk to rescuers. SCBA if potentially unsafe levels of Hg Skin or clothing visibly contaminated with liquid Hg can contaminate rescuers equipment, clothing, or indoor environment. Wear gloves and foot protection since Hg spreads under nails very easily