Health Risk While Managing Mercury Contamination Michael Austin U of MN DEHS austi001@umn.edu 612-626-6436

Introduction AD for Industrial Hygiene and Safety Support DEHS staff at UMC, UMM and UMD Resource on art safety in UMTC – helped design the Regis Center for Art Risk management – standard of safety relative to average home safety

How DEHS is involved Mercury Clean-Up Guidelines Work Team Associated with implementing a an Environmental Procedures Plan Included MDH and MPCA representatives CPPM & DEHS Service Level Agreement Work Team Roles and responsibilities Meetings with MPCA to discuss enforcement interpretations

Shared Goals Minimize human exposure to mercury Minimize release to the environment

Metrics Milligram (mg) 1/1,000 (thousands) Microgram (ug) 1/1,000,000 (millions) Nanogram (ng) 1/1,000,000,000 (billions) To make comparisons easier we use nanograms / cubic meter as a reference for concentration in air

Why we care about mercury Mercury and compounds are toxic Damage to brain Damage to kidneys Neurological development of a fetus, infant or child can be impacted

Mercury containing devices are very common. Devices include: fluorescent light bulbs, thermometers, light switches and pressure sensing devices. These items have occasionally broken and caused low levels of contamination on floors and walls. A high percentage of demolition debris from old buildings is contaminated with trace amounts of mercury.

How we are exposed Ingestion of mercury Inhalation of vapor Mercury bioaccumulates in lakes and streams Fish bioaccumulate methylmercury Ocean shell fish have high organic mercury Average intake is 500 ng/Kg/day (me 50,000 ng/day) Inhalation of vapor Natural degassing of mercury from the earth Release of mercury by burning coal and wood Dental amalgams Spills

Simplified Inhalation Model (Borrowed from Rita Messing, MDH)

Elemental Mercury 70-80% of inhaled Hg is absorbed Poor absorption: skin GI tract (<1% absorbed) Symptoms of high exposure and high, long term exposure: Cough, metallic taste, inflammation of the mouth, chest tightness, chills, fever, weakness, GI upset, pneumonia, bronchitis Mad Hatter- tremor, paresthesia, hyperexcitability, memory loss Stomatitis – inflammation of the mouth Erethism – excessive excitement

Typical Blood and Urine concentrations 95th percentile in U.S. population Pb in blood 1-5 years 7000 ng/dL 6-11 years 4500 ng/dL 12-19 years 2800 ng/dL Hg in blood 1-5 years 2300 ng/dL 16-49 years 7100 ng/dL Hg in urine 5000 ng/L

Mercury health standards 200 ng/m3 chronic MRL – US Dept HHS ATSDR 300 ng/m3 RfC - EPA IRIS 300 ng/m3 - Minnesota Dept. of Health chronic exposure criterion for schools (breathing zone) 500 ng/m3 - Minnesota Dept. of Health residential standard 25,000 ng/m3 - American Conference of Government Industrial Hygienists (ACGIH TLV) 50,000 ng/m3 - MN OSHA PEL (a rule) 50,000 ng/m3 - NIOSH REL

U of MN health based spill cleanup goals Based on task force discussions including MN Dept. of Health Visible mercury always removed 500 ng/m3 in residential occupancies 850 ng/m3 in other public areas (residential exposure adjusted for time) 25,000 ng/m3 in work places with expectation of exposure

Questions and Comments