Small Dose of Mercury – 3/20/05 A Small Dose of ™ Mercury An Introduction To The Health Effects of Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Mercury the Metal

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Key Words Risk = Hazard X Exposure Dose / Response Individual Sensitivity

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology What Is This? Hg CH 3

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Methyl Mercury (MeHg) Hg CH 3

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Hg - Inorganic & Organic Hg CH 3 Inorganic – Quick Silver Hg Organic – Methyl Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Hg Facts & Uses Quicksilver 13.6 times the weight of water Evaporates at room temperature Bacteria change to Methylmercury Amalgam Many Industrial uses (thermometers, chemical reactions, gold mining)

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Hg – Like Water

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Hg – Solid Enough to Sit On

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Alchemy Medicine - cure syphilis? Egyptian tomb BC Ancient Awareness

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Greek God Mercury “For then she bare a son, of many shifts, blandly cunning, a robber, a cattle driver, a bringer of dreams, a watcher by night, a thief at the gates, one who was soon to show forth wonderful deeds among the deathless gods...” Description of the birth of the Greek God Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Occupational Exposure Gold mining. Hatters in the felt industry. Historical Events

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Historical Awareness

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Polluting with HG Discharge in Minamata Bay

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Fetal Effects of MeHg

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Life-Long Effects of MeHg

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Planting Seed with Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Iraq Mothers with Bread

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Iraq Infant - Effects of Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Coal Fired Plants – Hg Emissions

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Outbreaks of MeHg Poisoning PlaceYearCases Minamata Nigata Guatemala Ghana Pakistan Iraq Iraq19601,002 Iraq197140,000 On-going2001???

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Inorganic - elemental mercury vapor Hg 0 Biotransformation Organic - Methylmercury - CH 3 Hg + Bioaccumulatio n Mercury to Methyl Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Mercury Release 50-75% mercury of released in the environment related to human activities

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Atmospheric Hg

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Ambient Water Sediments Edible Fish Inorganic Mercury Methyl- Mercury In Humans Biomethylation Bioaccumulation Exposure Discharge Biotransformation of Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Natural Degassing of the earth Combustion of fossil fuel Industrial Discharges and Wastes Incineration & Crematories Dental amalgams Hg 0 Hg 2+ CH 3 Hg + Environmental Sources of Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology The Mercury Cycle

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology A 270-year record Major atmospheric releases Natural Background (42%) Volcanic (6%) Anthropogenic (52%) Gold rush WWII Industrialization Significantly The last 100 years anthropogenic: 70% The last 10 years an apparent decline

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Blindness - Deafness Cerebral Palsy - Seizures Abnormal reflexes & muscle tone Retarded motor development Visual and Auditory Deficits Delayed motor development Altered DRH performance Neurobehavioral Effects

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Decrease in Brain Size Cell loss Disorganization of cells Cell migration failures Effects On The Brain

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology  MONKEY - 25 µg/kg - LOAEL  RAT - 10 µg/kg - LOAEL  RAT - 50 µg/kg - replicated Animal - Risk Assessment

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology  2.5 µg/kg - NOAEL (animals)  0.25 µg/kg - Human  µg/kg - Sensitive populations Animal - Risk Assessment (the rule of dividing by 10)

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology ppm hair - LOAEL ppb blood - LOAEL µg/kg 0.06 µg/kg - RfD Human - Risk Assessment

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Mercury Fishing Advisories  In 2000, 41 States have over 2000 fish consumption advisories  An increase from 27 in 1993  Pregnant women, nursing mothers, women who intend to have children, and children under 15

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Reduce environmental release Restrict global production and sale Advise women of child bearing age Research mechanisms of action Assess neurodegenerative effects Recommendations

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology MeHg Consumption Limits US EPA – 0.1 ug/kg-day US FDA – 1 ppm (mg/kg) in tuna

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Mercury A Global Issue Mercury distribution and exposure is a global problem

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Alice’s Adventures “Everything’s got a moral, if you can only find it” Lewis Carroll in Alice’s Adventures in Wonderland

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology A Small Dose of ™ Mercury

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Additional Information  Web Sites  World Health Organization - global prospective on mercury health effects. GDWQ/Chemicals/mercuryfull.htm  US EPA - Main site on Mercury.  The Mercury Policy Project (MPP). - works to raise awareness about the threat of mercury contamination -

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology Authorship Information For Additional Information Contact Steven G. Gilbert, PhD, DABT Web: This presentation is supplement to “A Small Dose of Toxicology”

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology State - Risk Assessment 26 States - Fish Advisories Pregnant women, nursing mothers, women who intend to have children, and children under 15

Small Dose of Mercury – 3/20/05 A Small Dose of Toxicology 34 States - Fish Advisories 26 of 34 - Women and kids >0.16 ppm limit consumption State - Risk Assessment