The present methods
of storage and disposal of many chemical wastes and other toxic
substances pose severe risks to human health and to the viability
of other species and ecological processes. All countries produce
and dispose of hazardous substances on an increasing scale, but
many of them, especially developing countries, lack awareness of
the hazards. They also lack the data and analytical capacity needed
for the safe management of hazardous wastes. After decades of
uncontrolled dumping, industrialized countries and an increasing
number of developing countries have discovered that the cost of
ignorance and neglect is extremely high in terms of air, water, and
land pollution and consequent harm to health and
productivity.
The traditional low
cost methods of hazardous waste disposal are landfill, storage in
surface impoundments, and deep-well injection. Recently, thousands
of landfill sites and surface impoundments used for dumping
hazardous wastes have been found to be entirely unsatisfactory;
corrosive acids, persistent organics, and toxic metals have
accumulated in them for decades. Estimates of the costs of cleaning
up existing dangerous sites range from $1 billion in Denmark to $10
billion in the Federal Republic of Germany and $23 to 100 billion
in the United States. Some of the unsatisfactory dumping has
exposed people directly to hazardous chemicals. In two major cases
in the Netherlands and the United States, homes were built on
reclaimed land containing paint solvents, pesticides, chemicals
used in making plastics, and the sludge from the bottom of stills.
Hundreds of families had to be evacuated from the sites in both
cases. For the U.S. site, the cleanup costs reached tens of
millions of dollars and there were many serious health problems in
children living on and near the site. In Japan in the 1950s and
1960s, mercury discharged from a chemical factory into the sea
contaminated fish eaten by local people; nearly two thousand people
suffered neurological disorders and about four hundred died.
Although dumping of waste at sea is now controlled under
international and regional contentions, several countries are still
using this method for the disposal of hazardous waste, and
underground storage of hazardous waste is practised on a limited
scale in a few developed countries.
Several physical,
chemical, and biological methods can be used to reduce the bulk or
toxicity of the waste. Of all the treatment technologies available,
properly designed incineration systems can provide the highest
overall degree of destruction and control for the broadest range of
hazardous waste streams. Ideally, incineration should produce
carbon dioxide, water vapour, and inert ash. But small quantities
of a multitude of other more dangerous emissions may be formed.
Such emissions appear to pose little increased risk to human
health, but more detailed studies are needed. Rising costs, scarce
treatment capacity, and public opposition to new treatment and
disposal facilities plague hazardous waste disposal programmes
virtually everywhere. Incineration at sea in specially designed
ships costs much less than land-based incineration, since emissions
are not as tightly controlled. However, there is now a trend to
limit marine incineration or ban it altogether.
As controls on
hazardous waste disposal have been tightened in some countries,
industries have increasingly resorted to exporting their waste to
foreign countries. Recent publicity about the dumping of hazardous
wastes in some African countries has triggered widespread concern.
The shipment of hazardous wastes from the North to the South is
likely to grow even if illegal dumping is prevented. Developing
countries may accept hazardous wastes in return for hard currency
or needed industrial goods, even though it is extremely difficult
for them to ensure that the wastes are properly handled and
disposed of. Export of hazardous wastes transfers the risks
involved to the importing countries, without necessarily
transferring the knowledge or managerial capability to deal with
them. Transboundary transfer of hazardous wastes may magnify such
risks, therefore, and it weakens incentives for reduction of waste
generation at the source. Reduction at the source appears to be the
most reliable way to reduce the impact of hazardous waste, and is
probably the cheapest in the long run.
Despite some
encouraging examples of new low-waste technologies, recycling, and
other innovative measures, few of the potential gains have so far
been achieved. About 4 to 5 per cent of hazardous wastes are being
recycled in some OECD countries, but using existing technologies
there is a great potential for recovering up to 80 per cent of
waste solvents and 50 per cent of the metals in liquid waste
streams in the United States. Japan seems to have advanced the
furthest of any major industrial country toward recycling and
reusing its industrial waste, largely thanks to a cooperative
relationship between industry and government. In Japan, the United
States, and Western Europe, there are waste exchanges operating on
the simple premise that one industry's waste can be another's raw
material. They have succeeded to varying degrees in promoting the
recycling and reuse of industrial waste. The United States
Environmental Protection Agency has estimated that existing
technologies could reduce the total amount of hazardous wastes
generated in the United States by 15 to 30 per cent by the year
2000. More vigorous research and development in recycling and waste
minimization technologies, together with technical and financial
support to encourage investments in them and, in some cases, taxes
on waste generated, could probably cut the production of hazardous
wastes by one third in many industrialized countries by the year
2000.
Until more
production processes that produce far less hazardous waste can be
devised and implemented, technical and regulatory measures will be
necessary. They will be needed to ensure safe handling and disposal
of the existing output of waste, especially in the developing
countries. These measures should include methods to evaluate
alternative means and sites of waste disposal and to assess the
implications of importing such wastes. But few developing countries
have established the basic foundation of a hazardous waste
management system. Most have no regulation, no trained manpower,
and no facilities capable of adequately treating and disposing of
hazardous wastes. An active exchange of information and experience
between developed and developing countries could do much to advance
the latter's capabilities to deal with such wastes. Special
emphasis should be put on strategies of waste minimization,
recycling, and reuse that could yield large economic and
environmental gains.
More than 100
countries signed the Final Act of the Basel Convention on the
Control of Transboundary Movements of Hazardous Wastes and Their
Disposal in March 1989. This Act deals with exchange of
information, technical assistance, and control measures. Under the
terms of the Convention, the signatories cannot send hazardous
waste to another signatury that bans imports of it, or to one that
does not have the facilities to dispose of the waste in an
environmentally sound manner, or to any country that has not signed
the Treaty. An exporting country must have the importing country's
consent, and must first provide detailed information to the
importing country to allow it to assess the risks. When an
importing country proves unable to dispose of legally imported
waste in an environmentally acceptable way, then the exporting
State has a duty either to take it back or to find some other way
of disposing of it in an environmentally sound manner. Shipments of
hazardous waste must be packaged, labelled, and transported in
conformity with generally accepted and recognized international
rules and standards. The Treaty calls for international co-
operation involving the training of technicians, the exchange of
information, and the transfer of technology. It also asks that less
hazardous waste be generated and that such waste be disposed of as
close to its source as possible.
The ultimate goal of
the Convention was to make the movement of hazardous waste so
costly and difficult that industry will find it more profitable to
cut down on waste production and recycle what waste they produce.
But a total ban on the movement of hazardous waste is neither
practical nor desirable. The Executive Director of UNEP has noted
that only about 20 per cent of the hazardous waste generated in and
exported from industrialized States is shipped to developing
countries. In the near future, developing countries will be
exporting hazardous waste to developed countries. Nigeria is
already shipping hazardous waste to the U.K. This Convention can
give great impetus to minimizing the production of hazardous wastes
and the risks of dealing with them, once the necessary 20 countries
have deposited their instrument of ratification with the
Secretary-General. As of 12 December 1989, more than 40 countries
had signed the Treaty itself, but only Jordan had deposited its
instrument of ratification.
