Waste as a driver of change
Part 1: The nature of the
problem
and why we have it
Introduction:
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Fig.1
Humans use the term “waste” to describe materials
that have been used but are
no longer wanted.
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No
organism is 100% efficient. As resources are consumed, wastes inevitably are
generated. The actions of humans are no exception, and waste is an unavoidable
aspect of our existence. However, as human society has developed, the wastes it
produces have changed, in both nature and quantity.
“Waste”
is the general term used for any unwanted or undesired material, yet it is not
easily definable. No definitive list exists of what does and does not
constitute “waste”. Under European legislation, it is “any substance or object
the holder discards, intends to discard or is required to discard”. The
legislation states that once a substance has become waste, it will remain waste
until it has been fully recovered and no longer poses a potential threat to the
environment or to human health.
Interestingly,
this definition highlights the important notion that “waste” is an
anthropogenic concept. Humans use this term to describe materials that have
been used but are no longer wanted, either because they have no more value to
us or because they no longer serve the desired function. In contrast, natural
ecosystems have evolved to be highly efficient, with the waste products
produced by one organism becoming the feed stocks for another. In this sense
wastes are not “wasted” but instead used as resources. “Waste” as we know it
does not exist.
The problem for us is not the production of waste in
itself, but rather the quantity now generated by society, its toxicity, and the
impact that our inefficient use of materials has on resource depletion, climate
change, the environment, and human health in all corners of the planet.
Managing
the waste we generate is a formidable challenge for governments around the
world.
How
to dispose of refuse economically and without degrading the environment is a
problem shared by developed and developing countries alike. Yet, are
governments missing the point? Should we not be addressing the causes of the
problems, rather than just looking for end-of-pipe solutions?
What is the problem?
The scale of the
problem
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Fig. 2 Territory size
shows relative proportion of the
world's population living there.
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Fig. 3 Territory
size shows proportion of total
global municipal waste generated there.
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These
trends can be mapped graphically. When comparing total municipal waste generation
against the population of countries across the world, it highlights that
although China and the US generate similar net quantities of municipal waste,
the latter produces a much higher rate per capita.
In
terms of recycling, developed economies collect a high net quantity of waste
for recycling, but this is in part due to them producing large amounts of waste
in the first place. Interestingly the US, which collects a high net volume of
material for recycling, does not appear in the list of the top 10 countries
with the highest recycling rates (Fig. 2-4).
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Fig. 5 Waste and wealth: links
between
increasing GDP and waste generation.
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Fig 6. Global household expenditure.
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What are we
producing?
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Fig. 7 Composition of municipal solid waste
(MSW) in the USA and Uganda (%).
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The nasty side of
waste:
The wastes produced by modern
society and industry can have far-reaching and sometimes long-term and
irreversible consequences for human health and the environment. Of particular
concern are the hazardous wastes that lie behind the luxury and convenience of
modern living. Even the materials simply thrown away in our own bins can be:
(1)
ecotoxic - causing damage to the environment;
(2) carcinogenic - causing cancer;
(3)
persistent - remaining dangerous for a long time; and
(4) bio accumulative - accumulating as it makes
its way up the food chain.
Although
it is very difficult to place a figure on the global generation of hazardous
waste due to un-uniform definitions as to what does and does not constitute
hazardous waste, it is estimated to be upward of 150M tonnes every year.
Of particular concern are
electronic wastes, a category near non-existent just 20 years ago but now
rapidly becoming a global issue. Currently e-waste makes up ca.4% of waste in
the EU, but it is increasing fast, at ca.3-5% annually, three times faster than
the growth in total waste flow. In developing countries the situation is
similar, with e-waste estimated to triple between 2006 and 2010.
E-waste is of concern because electronic commodities
contain a complex mixture of materials and chemicals, which are very difficult
to separate and recover, and can be harmful to humans and the environment if
not disposed of correctly.
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Fig. 8 What is e- waste?
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A
typical computer comprises 23% plastic, 32% ferrous metals, 18% non-ferrous
metals (lead, cadmium, antimony, beryllium, chromium, mercury), 12% electronic
boards (gold, palladium, silver and platinum), and 15% glass. The toxicity of
the waste is mostly due to the lead, mercury, and cadmium, with the
non-recyclable components of a single computer containing almost 2kg of lead.
An additional factor is that much of the plastic used in computers contains
flame retardants, which makes it difficult to recycle. Old computers tend
either to end up on landfill or be exported to developing countries for reuse.
However there are many reported cases of exported computers being dismantled
and contaminating the environment.
Waste affecting human
health:
If
hazardous waste enters the environment it can have devastating consequences. One
of the earliest waste disasters took place in the Japanese fishing village
Minamata, where in 1953 people began to experience headaches, convulsions, and
blindness. By 1966, 43 people had died and 66 had become permanently disabled
by the illness. “Minamata Disease”, as it became known, was caused by the
release of methyl mercury in industrial waste water from the Chisso Corporation
chemical factory between 1932 and 1968. The mercury bio accumulated in the food
chain and poisoned the local inhabitants when they ate locally-caught fish and
shellfish, resulting in the deaths of over 2000 people in the area.
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| Fig. 9 Bio-accumulation |
As of March 2001, 2955 individuals
had been officially identified by the Japanese government as having contracted
Minamata disease, but the real number is likely to be significantly higher,
with around 20000 people having applied to the Japanese government to be recognized
as sufferers. Chemicals are still regularly contaminating the environment and
finding their way into the food chain (Fig 9). This can happen through direct
discharge from industry as at Minamata, via waste leaching at disposal sites,
through direct application of pollutants into the environment, or accidental
spillages and leaks. The issues of bio accumulation of wastes in the food chain
were first presented to the general public in 1962 by Rachel Carson. Her famous
book, focusing on the dangers of the agricultural pesticide DDT, shocked the
public and triggered awareness that hazardous wastes can persist in the
environment and build up in the bodies of wildlife and people. DDT was
eventually banned in many countries, but it is still used in parts of the
developing world.
Today,
new chemicals are causing problems. A 10-year study by WWF looked for chemical
contamination in a wide range of food items in seven European countries and
found it in all of them. For example PCBs (poly chlorinated biphenyls), which
are globally banned and have been shown to adversely affect neurological
development, were found in every food item in the analysis. Phthalates are used
to soften plastics and are found in numerous consumer products from vinyl
flooring to cosmetics, but they are also endocrine-disrupting chemicals that
interfere with hormones. Being soluble in fat, they bio accumulate in fatty
foods causing health risk to those who consume them. As previously noted,
mercury can enter the environment through waste streams, and it is estimated
that up to 10% of American women carry mercury concentrations near the levels
considered to put fetal development at risk of neurological damage.


















