Transcript Hgtrend050422

Anthropogenic Mercury Mobilization and Emissions in US and Florida,
1930-2000
Janja D. Husar and Rudolf B. Husar
Washington University,
St. Louis, Missouri
Supported by
Florida Department of Environmental Protection
Tetra-Tech, Inc
Health and Environmental Concerns
The importance of mercury (Hg) as an environmental
contaminant stems from its omnipresent nature, due largely
to the magnitude of sources, its volatility, mobility, and
persistence.
• Elevated mercury concentrations are present in
the upper levels of the food chain in southern
Florida and Upper Midwest.
• Recently, Northeast has been added to the
warning list, NY Times, April, 2005
• Warnings issued predominantly to pregnant
women and children
Mercury Sources
Mercury is a building block of planet Earth (trace element).
Mercury metal is liquid and evaporates, depending on
temperature and barometric pressure. Natural systems, wind, rain,
volcanic disturbances shift mercury location.
MAN-MADE sources add to the environmental burden by taking
mercury from its geological deposits and redistributing mercury
to AIR , LAND and WATER.
Mercury in environment is either in elemental form or reactive
gaseous mercury (RGM).
Atmospheric residence time
Hgo order of 90 days
Hg2+ (RGM) order of days.
Biomagnifications of Hg
• Atmosphere is a transmission medium – no accumulation
• Mercury is concentrated in the food chain.
Approach for Assessment of Anthropogenic Mercury
Mercury Inputs
Mercury in goods
Mercury in fuels
Multi-Scale: National, Florida, Southern Florida
Mercury mobilized in coal
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Each coal mining region has a specific Hg content; •
USGS has extensive data for each coal region
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Hg mobilization = S (Hg Conc. X Coal Production) •
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Most of coal in FL is from the Appalachian Basin
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The total Hg mobilized in coal has been 80160 Mg/yr since 1900
The Hg fraction emitted during combustion is
50-75%
The coal Hg emission ranged 60- 120 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 30,000 ppb.
Fate of Hg in Crude Oil
Assuming 10 ppb in crude oil
Hg conc, ppb
“Other” still gas, naphtas,
unfinished oils, petroleum
coke (consumed at refineries
and electric utilities), etc
LPG
10
Distillate fuel
5
Motor gasoline
2
Residual fuel
10
Other
50
US Mercury Mobilization Trend
Hg Mobilization:
Fuels
- Coal
- Crude Oil
Goods
– Chlor-alkali
– Pharmaceuticals
– Agriculture,
fungicide
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–
–
–
Paint, fungicide
Lab use
Electrical, batteries
Control, manometers
Dental, amalgamation
Other
Data: Bureau of Mines (BOM), USGS, and DOE
Mercury Mobilized in Goods: Electrical Sector
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Batteries were dominant until 1990
Hg in alkaline batteries were discontinued,
beginning the 1980s
Hg is still used in lights and switches
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Consistency of ‘electrical’ Hg use:
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Bureau of Mines reports Hg consumption
Franklin reports Hg in discarded goods
Mercury in Paint
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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
Mercury Flow in Goods
Mercury NOT distributed with goods
• Chlor-alkali - 14,000 Mg/70yrs
Mercury distributed with goods
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Pharmaceuticals – 3,400 Mg/70yrs
Agriculture - 5,400 Mg/70yrs
Paint - 8,400 Mg/70yrs
Lab use – 1,800 Mg/70yrs
Electrical – 29,000 tons/70yrs
Control – 10,000 Mg/70yrs
Dental – 3,200 Mg/70yr
Mobilized in 70 years ~112,000 Mg
Data: Bureau of Mines (BOM), USGS, and DOE
Mercury Mobilization -> Atmospheric Emissions
Electrical
Control
Lab use
Dental
Pharmaceuticals
Petroleum
Coal
Paint
Agriculture
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100%
AIR
50-75% Air
66% Air
100%
Air+Land
Land
Atmospheric emission fraction is estimated for each mercury flow category
Emission = Hg flow in goods and fuels * Emission fraction
Mercury Emissions: USA
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The US mercury emissions were estimated based on the Hg flow and emission fractions
Nationally, coal combustion and electrical use contributed the bulk during 1930-1990
Note the the significant paint contribution to the atmospheric emissions, 1960-1990
Mercury Flow: US -> Mercury Flow: Florida
Mercury Flow: US
Electrical
Control
Lab use
Dental
Pharmaceuticals
Paint
Mercury Flow: Florida
Population prorated
Acreage use prorated
Agriculture
Coal
Petroleum
Florida specific
Mercury in Coal and Petroleum: Florida
Source of Coal Hg
E Kentucky
• The Hg mobilized in coal increased to about 5 Mg/yr
• The coal Hg emission ranged 2.5 - 4 Mg/year in the 1990s
• 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
Cumulative Hg Flow: ~2000 Mg/70 yrs
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 (1930-2000).
Waste Combustion Fraction and Rate
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The emission fraction of municipal waste was
between 10 and 30% for the US
The decline (1960-1980) was due to closing of
incinerators
Recent increase is due to regulated incineration
(WTE) units
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Paint mercury in FL occurred in 1960-1990
Assuming 75% emission fraction, the emission
rate was ~8 Mg/yr for 1970-1990.
Mercury Emissions:
US and Florida
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The US Hg emission ranged
between 300-500 Mg/yr (19401990).
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The Florida Hg emissions have
increased from 5 to 15 Mg/yr
during the 1940-1990 period.
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Nationally, coal was a
significant contributor
throughout the period.
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In Florida, coal became
significant in the 1990s
Mercury Emissions:
Comparison of Florida DEP – Material Flow Method
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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.
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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.
Broward County mercury flow and emissions
Paint and electrical goods
contribution was the largest in
the Broward County.
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 mobilization peaked in 1960-1990 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
1960-1990 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
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The emission fraction of municipal waste
was between 10 and 30% for the US
The decline (1960-1980) was due to
closing of incinerators
Recent increase is due to regulated
incineration (WTE) units
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Data
Mercury in Agriculture: Florida
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Florida mercury agriculture use
Comparison of RMB and flow method
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Three county comparison. Electrical, control, and lab use were incinerated at
reported WTE rates, for 1990-1998. 1980-1980 incineration was apportioned
using Florida factors
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