Daniel J. Jacob, Harvard University

Mercury in the Arctic Environment

Hg

Hg

A brief human history of mercury poisoning

Qin Shi Huang,1st emperor of China

Mad hatters

Minimata disaster

Karen Wetterhahn,Dartmouth professor

Iraq grain disaster

200 BC

19th-20th century

1950s

1971

1997

The perilsof eating too much fish

Jeremy Piven, actor Richard Gelfond, IMAX CEO

Both hospitalized for extended time due to mercury poisoning from daily fish consumption over many years

Mercury from fish consumption: a global environmental issue

Children IQ deficits (fetal exposure)Well-established

$8 billion per year cost in US

Adult cardiovascular effectsSuspected

EPA reference dose (RfD): 0.1 μg kg-1 d-1 (about 2 fish meals per week)

Hg

(m

g/k

g)

Til

efis

hS

har

k

Sw

ord

fish

Ora

ng

e R

ou

gh

y

Mar

lin

Can

ned

Tu

na

(alb

)

Blu

efis

hG

rou

per

, R

ock

fish

Sco

rpio

nfi

sh

Hal

ibu

t

Sea

tro

ut

Sab

lefi

sh

Lo

bst

er

Sn

app

er

Lo

bst

er

Mac

kere

lS

kate

Can

ned

Tu

na

(lt)

Co

dC

roak

er

Sq

uid

Wh

itef

ish

Po

llo

ck

Cra

b

Mercury biomagnification factor

Sal

mo

n

Mercury is a particularly important issue in the Arctic

High mercury concentrations, dependence on populations on seafood

Mercury is present in the atmosphere as an elemental gas

ArgonCO2

Watervapor

OxygenHelium

Mercury Nitrogen

It is the only metal that behaves that way!

Natural cycle of mercury

mercury

burial

SEDIMENTS

uplift

volcanoeserosion

mercury

HUMAN PERTURBATION:coal combustion

mining

ATMOSPHERE

OCEAN/SOIL

deposition

re-emission

food chain

Rising mercury in the environment

Dietz et al. [2009]

Mercury in Wyoming ice core Mercury in Arctic wildlife

Human perturbation started in Antiquity; present-day mercury levels in global environment are about ten-fold higher than natural

Global transport of mercury through the atmosphere

Circle around mid-latitudes: 1 month

Transport to southern hemisphere:1 year

Implies gPresent-day cale transport of anthropogenic emissions

Mercury emitted anywherecan deposit to oceans worldwide

Present-day emission of mercury to atmosphere from coal and mining

Atmospheric concentrations

UNEP [2013]; Soerensen et al. [2013]

UNEP Minimata Convention on MercuryFirst major global environmental treaty in over a decade

• Requires best available technology for coal-fired power plants• Mercury mining to be banned in 15 years• Regulation of mercury use in artisanal

gold mining

Opened for signatures in October 2013; signed by 128 countries so far

Convention requires ratification by 50 countries to go into effect; twelve (including the US) have ratified so far

signed ratified

“Grasshopper effect” keeps mercury in environment for decades

Amos et al. [2014]

Res

ervo

ir f

ract

ion

Fate of an atmospheric pulse:

AtmosphereSurface soils Deep soils

Surface/subsurface ocean Coastal sediments

Deep sediments

Deep ocean

mercury

deep oceanrivers

SEDIMENTS

Land Ocean

0

Helen Amos (Harvard)

Who is responsible for mercury in the present-day ocean?

Amos et al. [2013]

EuropeAsia

N America

S America

former USSR

Rest of world

pre-1850natural

by time of initial emission:

by source continent:

Half of human-derived mercury presently in the ocean

was emitted before 1950

Atmospheric mercury has been decreasing since 1990, despite increasing emissions from coal combustion

Why?

Zhang et al. [2015]

Long-term atmospheric data Long-term precipittation data

BLUE = DECREASE RED = INCREASE

Yanxu Zhang (Harvard)

Many commercial products contain(ed) mercury

Wiring Devices &Industrial Measuring Devices

Medical Devices

Pharmaceuticals & Personal Care Products

Pesticides and Fertilizer Explosives/Weapons

Dyes/Vermilion

Many commercial products contain(ed) mercury

Global historical use of mercury in commercial products

Horowitz et al. [2014]

Co

nsu

mp

tio

n,

Mg

per

yea

r

Year AD

Artisanal gold mining

Hannah Horowitz (Harvard)

Tracking the environmental fate of commercial mercury

Global mercury mined per decade

Commercial use by country

Disposal

Air Land Water

Landfill

Additional releases from commercial Hg in the context of atmospheric emissions

Historical release of commercial mercury to the environment

Hannah Horowitz (Harvard).

“Inadvertent” mercury (coal combustion, silver/gold mining)

Air

Soil

WaterLandfills

Co

mm

erci

al m

ercu

ry

Total release peaked in 1970, has been decreasing since

Atmospheric mercury in the Arctic is high and not decreasing;WHY?

2000-2009 trend

BLUE: decreaseRED: increase

Atmospheric mercury concentration

Jenny Fisher (Harvard)Fisher et al. [2013],Chen et al. {2015]

What is going on in the Arctic?

Large river inputs to shallow Arctic Ocean; melting sea ice allows mercury to escape

Ocean mercury, pM

mercury

mercury

Northern Dvina in Arkhangelsk

The wild card of climate change:potential mobilization of the large soil mercury pool

Global soils: 270,000 tons mercury Oceans: 330,000 tons

Atmosphere: 5,000 tons

Increasing soil respirationdue to warmer temperature

Climate change may be as important as emission controls for the future of environmental mercury in the century ahead.