MERCURY CONTAMINATION IN S-NEW ENGLAND AND LONG ISLAND SOUND, USA JOHAN C. VAREKAMP EARTH &...
-
date post
15-Jan-2016 -
Category
Documents
-
view
222 -
download
0
Transcript of MERCURY CONTAMINATION IN S-NEW ENGLAND AND LONG ISLAND SOUND, USA JOHAN C. VAREKAMP EARTH &...
MERCURY CONTAMINATION IN S-NEW ENGLAND AND LONG
ISLAND SOUND, USA
JOHAN C. VAREKAMP
EARTH & ENVIRONMENTAL SCIENCES
WESLEYAN UNIVERSITY
MIDDLETOWN CT USA
Mercury droplets on cinnabar (HgS)
MERCURY AND HUMAN HEALTHMercury has no known biological function and binds tightly to sulfhydryl groups, inhibiting molecular functions
•reduces membrane permeability
•reacts with and disrupts phosphate bonds in ATP/ADP
•replaces cations in important molecules
-SH
ENVIRONMENTALCONCERN
HUMAN HEALTH CONCERN:HG IS A NEUROTOXIN
Victim of the “Minamata Bay” (Japan) tragedy, the first documented disaster of Hg pollution (1954)
Exposure to mercury?
Eating fish or shellfish Breathing vapors (home, work)Dental work and medical treatmentsReligious rituals that include Hg
inhalation (Santaria in Haiti)
Fish ConsumptionPrimary form of human exposure to
methylmercury is through fish consumption.
Population at greatest risk: small children and pregnant women that consume fish
EPA - RfD is 0.1 ug MeHg/dayMaximum Hg-in-hair level is 1 ppm Hg
cumulative frequency distribution Hg in hair
0
10
20
30
40
50
60
70
80
90
100
0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000
interval Hg in hair ppb
%
Series1
Wesleyan University study: 35%> EPA limit (nationwide random sample shows 20% above EPA limit)
EPA limit
Hg Sources – USA1998
Annual Hgemissions,
106 grams/yr.Oil-Gas Fired power plants 0.2
Coal-fired power plants 46.9Municipal waste incinerators 26.9Medical waste incinerators 14.6
Commercial/Industrial boilers 25.8Ore metal smelting 0.16
Other combustion sources 10.8Total combustion related 125.4Chlor-alkali production 6.5
Other sources 12.1TOTAL 144
Delivery pathways of Hg to the coastal environment
• Atmospheric deposition in the watersheds and fluvial transport to the coast
• Point source contamination on land with fluvial transport to the coast
• Direct discharge through outfall pipes of waste water treatment plants
• Dredge and sludge dumping
QuickTime™ and aNone decompressor
are needed to see this picture.
Some important forms of Mercury in the environment:
Hg2+
oxidized
CH3-Hg-CH3
organic, volatile, lipophilic
Hg0
reduced,
elemental,volatile
CH3-Hgorganic, charged,
lipophilic
Hg2+
Hg0
reductionbioaccumulation
demethylation
methylation
volatilization
CH3-Hg+
(CH3)2-Hg
anaerobic
aerobic
(Sulfate reducing bacteria)
Hg Transport• Dissolved metals (e.g., in complexes
with dissolved organic matter)
• Attached to fine particles:
• Inorganic
• Organic
Repositories of metals• Coastal subtidal sediments (delivery
mainly by particulate deposition)• Coastal salt marshes and estuarine
marshes (delivery mainly by particulate deposition and to some degree through in situ atmospheric deposition)
Sediment Cores
• Environmental archives that contain contamination records of metals
• Record can be blurred by
–Chemical mobility in the sediment column
–Discontinuous sediment deposition (flood deposits)
–Bioturbation
504030201000
0
1
2
3
4
5
6
Depth, cm
137Cs, dpm/gr1963
Mercury Levels
• Normal modern soil background levels for mercury in the northeast USA are around 200 to 300 parts per billion– Mostly due to atmospheric deposition
• Sediment samples with higher Hg suggest point sources of Hg in watershed
• Hg inventories: total amount of Hg deposited on 1 cm2 over the full pollution period
30002000100000
100
200
300Background
Hg pollution
Hg inventory,ng/cm2
GRAIN SIZE EFFECT ON HG INVENTORIES
RMRG
DBFI
PI
SR
Mercury profile core Chapman Pond, CT River, CT
Mercury profile from core BFB3A, Farm River marsh, Branford, CT
20001950190018501800175017001650160015500
100
200
300
400
500 GI-1
PTB100
Age AD
Hg ppb
20001950190018501800175017000
250
500
750
1000
1250
1500
1750
Age, years AD
Hg, ppb
onset of 'hatting' industry in Danbury
Onset of severeHg contamination
Knell's IslandCore KI 1
Flood Deposits
"normal" peak level of Hg contamination in CT
Natural background Hg level
Core Backgr. Onset Peak Peak ModernSSSaaallltttmmmaaarrrssshhheeesss
ppb Hg AD ppb Hg AD ppb Hg
BI2 38 1850 329 1970 218BI3 58 1850 243 1939 145BI5 93 1850 474 1974 206PTB/J100 54 1890 159 1956 107GI 35 1860 398 1960 146E 36 1900 293 1959 97GA 53 1870 415 1972 326GK 55 1860 420 1967 296BFB3a 44 1800 525 1940 236BFA3 37 1810 469 1944 249BFL8c 54 1790 333 1997 333KI1 68 1800 1544 1964 177FFFWWWMMMaaarrrssshhheeesssCP3 103 1820 414 1964 358DM - - 453 - 118MMMtttnnn bbbooogggsssTM 42 - 267 - 214LL 44 - 356 - 276Average 54 1842 441 1962 219
MarshCore
Peak Hg* dep. rate,ng Hg cm-2 yr-1 (peakyear)
Modern Hg*dep. rate, ngHg/cm-2 yr-1
% drop
Guilford 22.8 13.8 40 %GK 17.6 (1970) 10.8 40 %GA 28.0 (1970) 16.7 40 %
Barn Island 10 6 40 %BI-2 8.6 (1965) 6.4 25 %BI-3 12 (1940-1950) 5 58 %
BranfordBFA3 35 (1950 -1960) 15 57 %BFB3 13 (1930 -1940) 10 24 %Modernatmospheric HgDeposition rate
Fitzgerald et al. 1 - 2 Av. :
40 %
Barn IslandPataguanset Guilford Branford Atmosphere0
5
10
15
Mercury Deposition RatesMeasured Modern Atmospheric vs.Calculated from Inventories
ng/cm^2 yr
THE STILL RIVER, WESTERN CONNECTICUT
~1955
Fowler Island core, Housatonic River
1401201008060402000
0500
100015002000250030003500400045005000
Depth cm
Hg ppb
~1900
~1950
~ 1800
Pope Island core, Housatonic River
Floods of 1955Wooster Square, Danbury
The floods of 1955 in Waterbury, CT after twohurricanes hit in a few weeks time
Norwalk River CoreHg Concentration vs. Depth of Norwalk Core
0
1000
2000
3000
4000
5000
6000
0 10 20 30 40 50 60 70 80 90
Average Depth of Sample (cm)
Average Hg Concentration (ppb)
1820
1900
1955
Housatonic River, Still River, Norwalk River: strong evidence for Hg from hat-making sources
Source signals modified by floods
The return of the mad hatter
Lee Hat Factory
Mallory Hat Factory
EVERYONE wore hats. Men, women,
Danbury, CT"The Hatmaking Capital of the World"
• Hatmaki ngstarte d in Danbu ~ 1780ry• Th e" carrotage" solution (H g i n nitric
acid) isuse d t o mak e fel t fro mfur• Th efelt-makin g isdon e in asteam
saturate d environmen , t an d th esteam-condens ate wit h H -g nitrat edrip s fromth ewal lsan d ru ns offin to theenvironment
• Danbu ry Hat production:1808 - 100,000 hat / s year1850 - >1 milli onhat / s yea r wer e made;
65 h at factorie sacti ve in Danbury1920 - >5 milli onhat / s year1943 - 'carrotage ' proce ssoutlawed
The Carroting Solution…had nothing to do with vegetables.
This bright yellow-orange solution of mercury and nitric acid was used to treat animal fur from pelts. It made the fur fibers mat into felt more easily.
Men working in Mallory’s carroting room
Benedict’s factory initially produced 3 hats per day
Background Hg contamination in central and eastern Connecticut, much higher levels of Hg contamination in western Connecticut (Still River and Housatonic River wetlands)
How about sediments from Long Island Sound?
R/V UCONN
Sampling mud
HG IN LIS SEDIMENT: GREATEST ENRICHMENTS ON THE WEST SIDE NEAR NEW YORK
-72.30-72.55-72.80-73.05-73.30-73.55-73.80-73.80
0
100
200
300
400
500
600
70096017
96024
WLIS
Longitude
Hg ppb
Housatonic RiverConnecticut River
60504030201000
50
100
150
200
1
10
100
1000
10000Hg
C. perfringens
Depth (cm)
Hg (ppb)C. perfringens
core G1C1
(c)
Hg Concentration vs. Depth of WLIS 75GGC1 Core
0
500
1000
1500
2000
2500
3000
3500
0 20 40 60 80 100 120 140 160 180
Average Depth (cm)
Average Hg Concentration (ppb) 1820
1975
Core near Execution Rock near NYC - 1975 peak is Hg-rich debris of unknown origin
Hg Concentration vs. Depth of B1GGC1 Core
0
200
400
600
800
1000
1200
1400
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190
Average Depth (cm)
Hg Concentration (ppb)
1820
1900
1955
Core in the delta of the Housatonic River
200019501900185018000
100
200
300
400
500
Cu
Pb
Zn
Hg
% Clay
Age years AD
Metals, ppm/ppb
A4C1 Housatonic Riversediment pulse?~1900 floods?
7000600050004000300020001000000
200
400
600
NYB
Westernmost SoundCentral-Western Sound
Eastern Sound
C. perfringens (spores/g dry sediment)
Hg (ppb)
R^2=0.98
R^2=0.78
First estimate of Hg sources for LIS
~30-35 % from Waste Water Treatment Plants
~20-25% from Housatonic River/Danbury (WLIS)
Rest from Connecticut River
Connecticut River watershedHousatonic River watershed
LONG ISLAND SOUNDFINE SEDIMENT TRANSPORTHG POINT SOURCESWWTPADADWESTEASTIN SITU AD
Hg ppbNatural Background Concentrations 50 – 100Peak Contamination, Atmospheric Deposition 400 – 700Modern Surface Sediments 200 – 300
Danbury: Old hatmaking sites/Still River 1000 – 60,000Ponds and wetlands in town 100 – 1000Still River Surface samples 1500 – 5500; 70,000Core samples near golf course 500 – 100,000Housatonic RiverPope IslandFowlers IslandLong Island HRCarting IslandPink House CoveKnells Island / Wheeler marsh
1000 – 5000500 – 2500100 – 2500100 – 2200100 – 1100100 – 2000
Long Island SoundCoresSurface sediment
50 – 120050 – 700
We have documented extensive Hg contamination in soils and sediments from a known point
source: hat-making!
How do we get rid of the Hg??
Phytoremediation
REMOVAL OF POLLUTANTS THROUGH PLANT UPTAKE:
STORAGE IN PLANT FOLLOWED BY PLANT REMOVAL
OR FOR HG
UPTAKE IN PLANT, REDUCTION TO Hgo AND THEN EMISSION OF VAPOR FROM LEAVES
Growth Experiment
Brassica rapa P. (Mustard Spinach)
1. Good correlation between Hg in leaves and Hg in spiked soils
2. No correlation between Hg leaves and Hg from ‘field contaminated soils’
3. Decrease in Hg in leaves over time
Hg in Maple Trees
Soils with 0.1 -- 75 ppm Hg
Hg in leaves increased over time
Positive correlation Hg(leaves) with Hg(soil)
Mean Hg loss from soils
Hg in ‘normal leaves’ minus Hg in ‘MER A leaves’
About 300 microgram Hg / m2 per growing season
Ten cm thick soil with 50 ppm Hg-about 103-104 yrs to clean up
CCCooonnncccllluuusssiiiooonnnsss
• Wetland sediments in CT have peak Hg contamination levels of 400-500 ppb Hg, with values 50-90,000 ppb Hg in the Housatonic & Still River Basins
• Most LIS sediments have 100-650
ppb Hg vs natural concentrations of ~ 50-100 ppb Hg
• Hg contamination started
~AD 1820-1850, coinciding with the Industrial Revolution (and hatting industry) and raised C.perfringens concentrationsË anthropogenic signals!
• Hg contamination hasdecreased by about 50 %since the 1960-1970's
• The Danbury hat-makingindustry has been animportant source of Hg forwestern CT and westernLIS, starting ~ 1800 AD
• The EË W increase in Hgconcentrations in LISsurface sediments:
1. More “fines” to the West2. Sediment inputs from the
Housatonic River, withppm levels Hg
3. Hg inputs from WWTP
PLANT EXPERIMENTS
HG UPTAKE DEPEND ON PLANT SPECIES AND HG SPECIATION IN SOIL
HG IN LEAVES FROM MAPLE TREES INCREASES WITH TIME AND REFLECTS SOIL HG
PHYTOREMEDIATION WORKS IN PRINCIPLE (MER A PLANTS DO NOT RETAIN MUCH HG IN LEAVES) BUT MAGNITUDE IS SMALL
ROLE OF PLANTS IN SOIL HG EMISSION IS NOT YET CLEAR
Thanks to CT Sea Grant College Program, CTDEP, USGS and the Mellon Foundation
for funding.
Much of the field and analytical work was done by Wesleyan University students Beth Goldoff,
Kate Lauriat, Bart Kreulen, Billo Jallow and Patrick Welsh.
THANKS TO YOU FOR LISTENING