The new Protocol on
Heavy Metals to the Convention on Long-range Transboundary Air
Pollution
WHAT ARE THE
PROBLEMS ASSOCIATED WITH HEAVY METALS?
24 June 1998
In the right concentrations,
many metals are essential to life and have several important
functions in biological processes. In excess, these same metals
can be poisonous. For instance, metal emissions from point
sources like mines or metal-producing industries can have a
detrimental impact on the surrounding area. But heavy metals from
anthropogenic emissions can be transported in the air over wide
areas and deposited far from their sources.
In general, it would be fair to
say that the threats are associated mainly with mercury, cadmium
and lead -- the three heavy metals that the new Protocol
addresses.
Major environmental problems
resulting from the long-range transboundary transport of heavy
metals have been documented. For example, cadmium has accumulated
in agricultural soils and been taken up by crops. This has
affected consumers, who suffer from high levels of cadmium in
their kidneys. It has also been observed that the fish from lakes
in the Nordic countries and North America have a
higher-than-usual content of methyl mercury. Methyl mercury can
damage the central nervous system. The greatest risk is to
foetuses. The damage takes the form of impaired neurological
functions in children below school age.
Locally elevated levels of lead
are also a threat to our health. Children are particularly at
risk. They can ingest lead from soils and street dust. There are
substantial amounts of lead stored in urban soils, too. The
ongoing accumulation of heavy metals is also a considerable
stress factor for the forest ecosystem and for tree vitality.
These effects are reinforced by the acidification of soils.
Where do heavy metals come
from?
The main sources of mercury and
cadmium emissions are coal combustion in power stations and
heating plants, production of non-ferrous metals like copper and
lead, refuse incineration and chlorine production (Hg). Rocks
also emit mercury. The major sources of lead emissions are metal
production and leaded petrol.
What will the Heavy Metals
Protocol do?
The Protocol will set a
framework for national legislation and lead to a substantial
decrease in mercury, cadmium and lead emissions in Europe and
North America. Its basic obligations envisage a wide range of
actions:
- Countries have to reduce
their emissions below 1990 levels.
- Mandatory emission limit
values will be set for new and existing industrial and
energy production sources.
- It will become mandatory
for new and existing installations to use best available
techniques, such as filters, switching to clean fuels and
mercury-free processes.
- Leaded petrol will be
phased out.
- Product management measures
to reduce or phase out mercury, lead and cadmium in
products will be recommended.
The Convention on Long-range
Transboundary Air Pollution covers 42 countries in Europe and
North America and the European Community, all of which will be
free to sign the new Heavy Metals Protocol. The Convention and
the experience gained can also be used to initiate discussions to
reduce emissions of heavy metals in a wider context. Mercury is
transported around the whole of the northern hemisphere.
The Protocol will enter into
force when it has been ratified by 16 countries. Once in force,
it will considerably ease the environmental problems associated
with mercury, cadmium and lead. The Protocol will be an important
step towards reaching environmental goals and protecting our
health.
For more information,
please contact:
Mr Lars NORDBERG
Deputy Director
UN/ECE Environment and
Human Settlements Division
Palais des Nations,
office 346
CH - 1211 Geneva 10,
Switzerland
Phone: (+41 22) 917 23
54
Fax: (+41 22) 907 01 07
E-mail: [email protected]