Trends of Mercury Flow over the US with Emphasis on Florida Progress Report by Janja Husar and Rudolf Husar Submitted to Thomas Atkeson, Florida DEP May 2001

Background Goal: Develop a trend database for mercury flow over the US. Special emphasis on mercury flow through fuels, time epoch and the geographic region of Florida. Approach: Materials flow methodology. Mercury budgeting from the production (mining) through processing, consumption to the disposal in air, land and water.

Review, Summary and Evaluation of Recent Literature

Trend of the US ‘Apparent’ Mercury Supply, Apparent supply is = primary and secondary production + net imports + gov. stockpile releases From 1970 to 1986, the main contributors were primary mine production and imports During , there was a rapid decrease of apparent Hg supply caused by reductions in batteries, paint and fungicide From 1993 on, there was no primary mine production, expanded secondary production (recycling) and stock changes Given the 1998, consumption of 417 Mg/yr, the US has a 27 year stockpile of mercury. Sznopek and Goonan, 2000 MiningProductionConsumption Recycling Stock Mine ProductionSecondary Production Net Import Stock Release

Domestic Flow of Mercury, 1996 Sznopek and Goonan, 2000

Mercury in consumer goods and mined coal mercury in industrial goods was not well categorized (lumped into ‘other’ category) electrical and electronic instruments category (including batteries) was the dominant Hg industrial consumer. Hg consumption for industrial goods was reduced from around 2000 Mg/yr in 1990 to about 500 Mg/yr in 1995.

Mercury in US consumer goods and coal in 1990s Chlor-alkali and electrical and electronic instruments are still dominant users of mercury. Coal mined and consumed in US contributes about 140 Mg/yr

Atmospheric Emissions of Mercury According to the EPA Report to Congress, atmospheric emissions of mercury are dominated by coal and oil combustion (53%) EPA Mercury Study Report to Congress, 1997

Mercury Flow through Coal over the US Introduction Approach

US Coal Production by Region Coal production in the US occurred over five major producing regions. The coal production over the eastern US has remained roughly constant throughout the century. The sharp increase since the 1980s is due to the addition of western coal.

Mercury Content of US Coals Each coal producing region has a well defined range of coal mercury content. Evidently the pattern of coal mercury content is highly variable. USGS has an extensive database of coal mercury content covering most of the regions. Regional Hg content Appalachian 0.20 ppm Eastern Interior 0.09 ppm Gulf Coast 0.24 ppm Rocky Mountains 0.11 ppm Great Plains 0.12 ppm

Mercury Mobilization by Coal Producing Region The mercury mobilization follows the pattern of national coal production. Since the beginning of the century there was a slight decline (from 0.18 to 0.14 ppm) of average coal mercury concentration due to shifts in regional production. There was a sharp rise since the 1980s. In 1995 the mercury mobilization by coal was 144 Mg/yr. This constitutes an upper bound on coal mercury emissions to the atmosphere. Average Hg in US Coal, ppm

Mercury Flow through Coal in Florida Introduction Approach: –Determine the origin of the coal used in Florida –Assign mercury concentration to each coal source –Estimate the fraction of Hg retained at the mines and fly ash (25-50%) – Calculate the coal mercury emission rate for 1985 and 1998.

Origin of Coal in Florida Coal Origin: In 1985, the coal consumed in Florida was from Eastern Kentucky, Western Kentucky and Illinois In 1998, the coal consumed in Florida was more diverse. About 20% originated from Wyoming, West Virginia, Virginia Origin of Coal Hg in Florida Coal Hg Origin: Coal mercury in Florida is dominated by Eastern Kentucky coal with contributions from Western Kentucky and Illinois In 1998, the coal mercury included contributions from Wyoming, West Virginia, Virginia

Approximate Trend of Mercury in Coal Consumed in Florida The coal mercury content in Florida exhibits a slow rise between 1960 and 1980, sharp rise between 1980 and 1990, followed by constant levels in the 1990s. The 1998 estimated mercury content of mined coal used in Florida was about 4 Mg/yr. For the approximate historical trends an average coal mercury concentration of 0.15 ppm was assumed. The mercury emitted to the atmosphere is only a fraction ( ) of the mined coal mercury due to the retention at the mines (coal washing) and at the combustion plant as fly ash. The estimated coal mercury emission to the atmosphere in the 1990s was about 2-3 Mg/yr.

Summary and Plans Summary of Activities Studied and evaluated the recent literature on mercury flows over the US. Begun reconstruction of the coal mercury flow over the US. It is found that the relative contribution of coal mercury compared to other sources has been increasing over the 1990s. The coal mercury emission trends were crudely estimated, showing a sharp rise since the 1980s and leveling off in the 1990s. Immediate Plans Compile coal distribution and mercury content data. Estimate oil mercury flows.

Scrapbook: Ideas…unfinished pieces

Explaining Environmental Change The basic elements of life including carbon, nitrogen, phosphorus, calcium are in constant circulation between the earth’s major environmental compartments: atmosphere, hydrosphere, lithosphere, and biosphere. These earth’s compartments remain in balance as long as the rate of flow of matter and energy in and out of the compartments is unchanged. Changes in the environmental compartments will occur if the circulation (in and out flow) of the substances is perturbed. For example, the concentration of CO 2 in the atmosphere has been increasing because the rate of input into the atmosphere is larger than the rate of output. Trace metals, unlike C, N, P and Ca, have a slow and sluggish cycle through the four environmental compartments. Lead, mercury and other metals tend to accumulate in the lithosphere or parts parts of the biosphere. For example, it is said that once deposited, lead stays in the soil for 400 years.

Multimedia Mercury Flow Diagram (Tentative) Metals MiningProduction Consumption Recycling Air Land Water Hg Stocks Export/Import Fuel MiningRefiningCombustion Goods Flow Fuel Flow

Alternative Mercury Flow Diagram (In Progress) SupplyProductionConsumption Recycling AirLand FuelsIndustrial