Anthropogenic Mercury Flow in the US and Florida, Janja D. Husar and Rudolf B. Husar Washington University, St. Louis, Missouri Supported by Florida Department of Environmental Protection Tetra-Tech, Inc

Background Elevated mercury levels are present in the upper levels of the food chain in southern Florida. Recently, a significant decline of mercury in birds was observed. The cause of the sharp decline is not well understood. The objective of this study is to: Assess the trends of mercury flow in Florida since 1930

Approach Multi-Scale: National, Florida, Southern Florida National Mercury Flow Mercury from mining Mercury in fuels

Mercury Flow Methodology Flow method is based on mass balance applied to environmental compartments Mercury flow through the ‘environment’ begins by mining of minerals and fuels Along the flow, mercury is discarded to air, land and water

Mercury mobilized in coal Each coal mining region has a specific Hg content; USGS has extensive data for each coal region Hg mobilization =  (Hg Conc. X Coal Production) Most of coal in FL is from the Appalachian Basin The total Hg mobilized in coal has been Mg/yr since 1900 The Hg fraction emitted during combustion is 50-75% The coal Hg emission ranged Mg/year

Mercury Mobilized in Petroleum Unlike for coal, the Hg content of crude oil is highly variable and the data are sparse. Measured crude oil Hg concentration ranges between 10 and ppb. “ Other” still gas, naphtas, unfinished oils, petroleum coke (consumed at refineries and electric utilities), etc Fate of Hg in Crude Oil Assuming 10 ppb in crude oil

Mercury Mobilized in Goods: Electrical Sector Batteries were dominant until 1990 Hg in alkaline batteries were discontinued, beginning the 1980s Hg is still used in lights and switches Consistency of ‘electrical’ Hg use: Bureau of Mines reports Hg consumption Franklin reports Hg in discarded goods

Mercury in Paint Phenyl mercuric compounds used as fungicide in water-type (latex) interior and exterior paints Water-type paint consumption was increasing since the 1950s The average paint Hg concentration (Hg used/Water Paint shipped) was declining from >300 ppm

US Mercury Mobilization Trend Hg Mobilization: Goods –Electrical, batteries –Control, manometers –Dental, amalgamation –Pharmaceuticals –Chlor-alkali –Agriculture, fungicide –Paint, fungicide –Lab use –Other Fuels - Coal - Crude Oil Data: Bureau of Mines (BOM), USGS, and DOE

Mercury Flow -> Atmospheric Emissions Atmospheric emission fraction is estimated for each mercury flow category Emission = Hg flow in goods and fuels * Emission fraction Electrical Control Lab use Dental Pharmaceuticals Petroleum Coal Paint Agriculture 50-75% 100% 66% 0% AIR Land Air+Land

Mercury Emissions: USA The US mercury emissions were estimated based on the Hg flow and emission fractions Nationally, coal combustion and electrical use contributed the bulk during Note the the significant paint contribution to the atmospheric emissions,

Mercury Flow: US -> Mercury Flow: Florida Electrical Control Lab use Dental Pharmaceuticals Paint Coal Petroleum Agriculture Acreage use prorated Population prorated Florida specific Mercury Flow: US Mercury Flow: Florida

Mercury in Coal and Petroleum: Florida The Hg mobilized in coal increased to about 5 Mg/yr The coal Hg emission ranged Mg/year in the 1990s E Kentucky Source of Coal Hg The Hg in oil products reached ~0.2 Mg/yr Motor gasoline and residual fuel oil are the main contributors Note that petroleum Hg is <<< Coal Hg

Mercury Flow in Florida Mercury flow in Florida has been steadily increasing until the 1980s The electrical sector (batteries) was dominant throughout the period The electrical sector contributed 50% of the cumulative Hg flow ( ). Cumulative Hg Flow: ~2000 Mg/70 yrs

Waste Combustion Fraction and Rate The emission fraction of municipal waste was between 10 and 30% for the US The decline ( ) was due to closing of incinerators Recent increase is due to regulated incineration (WTE) units Paint mercury in FL occurred in Assuming 75% emission fraction, the emission rate was ~8 Mg/yr for

Mercury Emissions: US and Florida The US Hg emission ranged between Mg/yr ( ). The Florida Hg emissions have increased from 5 to 15 Mg/yr during the period. Nationally, coal was a significant contributor throughout the period. In Florida, coal became significant in the 1990s

Mercury Emissions: Comparison of Florida DEP – Material Flow Method In the 1990s, the Hg content of goods and paints has declined dramatically due to environmental regulations. Hg from coal combustion became comparable to the Hg in goods. The mercury emissions were estimated by the Florida DEP for Waste to Energy (WTE) incinerators. The corresponding (electrical, lab, control) emission estimates by the material flow method yield similar results.

Summary Hg mobilization is driven by combustion of Hg containing fuels (coal and oil) and by Hg use for goods (batteries, instruments, paints). The US mercury flow peaked in period at about 2000 Mg/yr, followed by sharp decline in the 1990s due to environmental regulations. The peak US atmospheric mercury emission rate was about 400 Tons/yr in the period. In Florida, the mercury flow and emission rate has increased rapidly in the late 1960s, and dropped sharply in the 1990s. The Hg flow and emission trends for Florida are now being reconciled with other data as part of the FCG and FL-DEP Mercury Trend Project.

Waste Combustion Fraction and Rate The emission fraction of municipal waste was between 10 and 30% for the US The decline ( ) was due to closing of incinerators Recent increase is due to regulated incineration (WTE) units Data

Mercury Flow: US -> Mercury Flow: Florida Florida Mercury Flow: Approach Electrical Control Lab use Dental Pharmaceuticals Paint Coal Petroleum Agriculture Acreage use prorated Population prorated Florida specific Mercury Flow: US Mercury Flow: Florida

Broward County mercury flow and emissions Paint and electrical goods contribution was the largest in the Broward County.

Mercury in Agriculture: Florida Florida mercury agriculture use

Comparison of RMB and flow method Three county comparison. Electrical, control, and lab use were incinerated at reported WTE rates, for incineration was apportioned using Florida factors

Biomagnifications of Hg Atmosphere is a transmission medium – no accumulation Mercury is successively concentrated in the food chain.