Environmental Management: Principles and practice

Electromagnetic radiation (non-ionizing)
Electromagnetic force (EMF) emissions are produced by microwave ovens, radar
transmitters, household power cables, radio and TV broadcasting, telecommunications
equipment, computers and high-voltage transmission lines. Stray EMF can cause
difficulties with legitimate radio and TV broadcasting, hospital equipment, research
activities, control systems in cars, aircraft, weapons, etc., and measures are taken to
shield against it and to legislate to control sources.
Epidemiological studies in the USA and by the Swedish National Board for
Industrial and Technological Development suggest high-voltage power cables might
cause childhood leukaemia, cancer and brain tumours; worries about portable-
telephone emissions are so far unproven. But so far there is no convincing proof that

---

CHAPTER ELEVEN
222
EMF of less than 100,000 hertz is dangerous to humans (Hester, 1992). However,
until proven completely safe, EMF should be treated seriously. It may prove necessary
to shield equipment much more carefully and to zone land use to keep transmission
lines and housing apart.
Coping with pollution and waste
Pollution and wastes are deemed hazardous if they threaten human health or
environment by virtue of their toxicity, ability to cause cancer or genetic disorders,
or because they transmit disease or pest organisms. Less hazardous material may be
a nuisance or unsightly.
Hazardous pollution and waste
Hazardous pollution and wastes can be grouped as chemical hazards, bio-hazards,
radiation hazards. In addition, emergency services and health and safety planners
usually recognize explosives and fire hazards. Chemical hazards include
organochlorine compounds and PCBs, which, once released, pose a long-term threat
even at low concentrations. At very low concentrations PCBs can mimic hormones:
one effect of this is to cause cancer, another is to disrupt reproduction in fish, reptiles,
birds and mammals. Nicknamed ‘gender benders’, these, and possibly other
background pollutants, have already disrupted fish and alligator stocks in various
countries, and there are fears that they might be reducing human sperm counts.
Unfortunately, these compounds are utilized in the manufacture of plastics and other
widely used materials.
Hazardous materials must be effectively labelled, carefully handled, stored
and used. They must either be securely isolated from the environment (sealed
containment) and after use treated chemically or biologically, or incinerated to render
them safe. Pumping material into rivers, the sea or the ground is widespread but
unsafe and so is increasingly being stopped. Containment is effectively storing
material, often without reducing its threat, and hoping time will reduce the danger.
Treatments seek either to neutralize a material chemically or biologically or to bind
it to something (e.g. vitrification) to prevent its escape or destroy it by heat.
To avoid emission of dangerous fumes or dust, incinerators must achieve
complete combustion at high temperature—to treat PCBs effectively requires over
1200°C for at least 60 seconds (British Medical Association, 1991). Even with back-
up filtration of flue gases and oxygen injection things can go wrong, so it might be
better to site hazardous waste incinerators in remote areas or on board ships that can
move to a suitable place. However, there has been criticism of shipboard hazardous
waste incineration (it may be difficult to oversee, and an accident means widespread
and untreatable contamination); in EU and North Sea waters a moratorium is in
force. America has companies which offer mobile (trailer-mounted) high-temperature
incinerators which can be taken by road to where decontamination is needed. However,
some countries like Canada are hesitating to rely on incineration.

---

POLLUTION AND WASTE MANAGEMENT
223
In the future particularly dangerous compounds may be treated in incinerators
at over 9000°C using solar power or plasma-centrifugal furnaces. Present treatments
can be expensive—PCBs, incineration or bioremediation (treating with micro-
organisms) cost US$2,000 to 9,000 per tonne of soil/waste treated (in 1995). Many
countries export hazardous waste for such treatment, either because they do not have
the expertise or facilities, or because it is cheaper, or a way in which commerce can
avoid tight environmental controls at home.
At present there is no cheap, effective way to decontaminate fissured rocks or
clays that have been deeply infiltrated by materials like PCBs or dioxins. Some soils
can be ploughed up and formed into banks, treated with bacteria and left for
bioremediation or could be transported for treatment at a decontamination facility.
Fermentation and oxidation may be sufficient to treat many pollutants. Bacteria and
yeasts are being bred to neutralize more effectively hazardous compounds (including
toxic chlorinated hydrocarbons and waste oil) in bioreactors, yielding a safe and
ideally useful end-product. For organic wastes, composting or fermentation can be
suitable strategies, yielding useful compost and methane. There has been considerable
interest in some of the bacteria found deep underground or around deep ocean
hydrothermal vents, in the hope that they might be used to effectively convert heavy
metal pollution to recoverable sulphates.
Chemical treatment of wastes ranges from simple disinfection (e.g. maceration
and chlorination or ozone treatment) to complex detoxification plants that chemically
convert materials like nerve gases. The environmental manager’s dream is a treatment
that gives a safe end-product of enough value at least to pay for treatment.
Asbestos, widely used for construction (e.g. roofing panels or cement-pipe
manufacture), insulation, fireproofing, and in vehicle brake and clutch linings, poses
health problems during manufacture, through dust generated when it is in use, and
when it is disposed of. Blue and white asbestos present the greatest threat; brown
asbestos is less of a hazard. Inhalation or ingestion, particularly of white or blue
asbestos, causes asbestosis, a chronic, debilitating, often fatal respiratory disease
that can manifest itself decades after exposure. The dust can be carried on the wind
and workers using the material may contaminate people downwind, and their families
and friends through dust on clothes. In developed countries controls have been greatly
tightened in recent years but in many developing countries they are still woefully
inadequate.