With rising awareness regarding the hazards of incinerating waste, a lot of proposals for incinerators have been ruled out in the West and the search for a viable alternative is on
Uproar over a burning issue
IRE is mounting globally against a technology that has existed for more than a
100 years now. Although it is not in
good taste to get up one fine morning
and start protesting about what has
been going on for ages, it is certainly
rational if done to ensure good health
and better environment. Incineration is
an industrial combustion process
designed to reduce unwanted materials
to simple solid and gaseous residues.
Unwanted materials can range from
solid municipal refuse to highly toxic
liquid and solid chemical residues.
Though in vogue for long it has now
been blamed for its devastating side-effects, including releasing of a cocktail
of pollutants into the atmosphere.
Emissions include particulate matter,
heavy metals, acid gases, oxides of
nitrogen and products of incomplete combustion, including chlorinated organic compounds (dioxins, furans, 61orobenzenes,
chlorophenols, etc). Incinerators
are of three types: municipal waste,
hazardous (industrial) waste, and
medical waste incinerators. The
design of the incinerator also influences the rate of particulate loading
in the flue gases. Other factors
influencing the emissions include
the incinerator size, grate type, and
the combustion chamber design.
Large incinerator units seem to
have slightly higher emission rates.
Its potential hazards have been
recognised since many years, and
there is a large body of knowledge
in the West that has initiated a mass movement against incinerators. Heavy metals like arsenic, cadmium, chromium, mercury, lead and nickel which have toxic effects are all released during combustion. Acid
gases like hydrogen chloride and sulphur dioxide are formed during combustion, when certain elements in
garbage come in contact with oxygen or
hydrogen, and are released into the
atmosphere. Oxides of nitrogen are
formed during garbage incineration by
the combination of nitrogen from the
wastes and oxygen from the atmosphere.
The ash which is left after combustion also contains a lot of toxic elements. Ash is of two types. Bottom ash,
which contains non-combustible and
incompletely burned solid matter, and
is generally dumped in nearby land, and
fly ash, which comes out of the incinerator during burning and escapes into
the atmosphere.
In many countries in Europe and in
the us, incinerator proposals are facing
delays and public opposition.
Opposition to commercial or merchant
sector facilities in the last two decades
has grown. As a result of this, plans for
new plants do not get approvals or may
face great delays in many countries.
Examples are the problems faced in
Spain and Australia for their proposals
to handle wastes. The '70s saw a rapid
growth in the concern over incineration
as a publt'c health risk. This was as a
result of & identification of chlorinated dibenzo-p -dioxins and dibenzofurans in municipal solid waste (msw)
incinerat 0@r emissions which coincided
with the release of 2,3,7,8-TCDD
(Tetrachlorodibenzo-p-dioxin) and
subsequent environmental contamination in a chemical accident at Seveso in
Italy.
The pollution that results from
incinerators is to a large extent
dependent on the type of waste that
is put into it. This in turn reflects
the consumption and production
patterns of the society as a whole.
For instance, plastic convenience
packaging content may be seen as
indicative of societal trends. Twice
as much plastic (five per cent by
weights of total waste) is found in
Italian and us' msw than that in
UK's MSW.
The advantage incinerators
have is that they reduce the bulk of
the waste and the remainder can
sometimes be used as fuel.
Incinerators reduce upto 90 per
cent in volume and 70 per cent in
weight of wastes, specially bulky
solids with a high combustible content. Destruction of some wastes
and detoxification of others renders them more suitable for final disposal as in the case of combustible carcinogens, pathologically contaminated
materials, toxic organic compounds, or
biologically active materials that could
affect sewage treatment works. It also
destroys the organic component of
biodegradable waste which when direct -
ly laridfilled generates landfill gas (LFG).
Incineration development has been
influenced by many factors like concerns over direct landfill of clinical
wastes, identification of problem wastes
for which incineration represents the
only commercially available method of
disposal and the recognition of energy
generation potential from wastes having
the capacity for adverse environmental
impact, if inappropriately disposed.
Incinerators are generally favoured
in communities offering the least political resistance. As a result, these facilities
are overwhelmingly found in areas
where the population is poor, elderly
and rural. In the US, more than half of
the nation's existing and proposed commercial hazardous waste burning facilities are located in rural communities
near agricultural lands.
Emerging evidence shows that these
hazardous waste incinerators contaminate the food chain and pose health
threats to the consumers who eat food
grown near incinerators. That the incinerators' emissions have a negative
effect on the crops is not well documented and statistically researched, but
is, nevertheless, a fact proved by field
studies and experimental tests.
One of the many problems with
incinerators is mercury, a large part of
which is pushed out into the atmosphere. Where there is an efficient battery collection system in place (as is the
case with a Swiss MSW incinerator), the
mercury levels in the feedstock have
been found to be considerably lower.
Waste incineration is responsible for the
emission of some 20 tonnes of mercury
into the atmosphere per year in
Germany. The behaviour of mercury is,
however, the least understood. One
method to minimise mercury emissions
is by changing the temperature in key
components of the plant, though this is
likely to cause problems with other
emissions.
In India, as in other countries, there
are no laws governing the disposal of ash from incinerators. If this metal-contaminated ash (specially in the case of
industrial indnerators) is disposed off
in landfills, it can result in metal mobilisation que to leaching.
This problem occurs particularly when incinerator
ash is disposed off with
other wastes, Similarly,
disposing off the ash from
MSW and hospital waste
incinerators is a problem,
This ash lands up in landfills and creates an acidic
environment.
Hazardous waste incinerators are supposed to
be different from ordinary
MSW incinerators. Surprisingly, however, hazardous industrial wastes
are routinely incinerated in facilities that are not designed for that
purpose. The problem components of
hazardous waste that is incinerated are
chlorinated solvents, PVC, pesticides and
pharmaceuticals.
Incineration of industrial wastes has
been practiced for the last 50 years, and
early units were based on MSW incineration technology itself. Rotary Kiln units
were the result of poor performance of
ordinary units in dealing with hazardous industrial wastes. The first rotary
kiln type of units were constructed in
Germany.
Water pollution from incinerators is
not generally regarded as an important
problem because of the limited amount
of waste water generated. However,
waste water from municipal waste
incinerator plants is contaminateq with
heavy metals and inorganic salts.
According to an US Environmental
Protection Agency report, "dioxins are
one of the most toxic chemicals known
and exposure to one molecule can be
harmful... Incinerators are the largest
producers of dioxins". There are more
than 210 molecular variations of chlorinated dioxins and furans in effluents of
incinerators. Interestingly, concentrations of dioxins from the same incinerator tested at different times can vary up
to 15 fold. One of the effects of exposure
to dioxins is infertility. It is also known
to cause birth defects and cancer and it
also effects agriculture. For example,
milk from cows grazing near a municipal incinerator in Switzerland contained
dioxin concentrations upto ten times those found in milk from other cows. In
terms of agricultural effects, lead has a
permanent effect on soil contamination.
Humans have secondary exposure to dioxins via milk and eggs.
A recent British study
showed marked concentration of larynx cancer
cases among adults in a
community within two-and-a-half km from a
ctomriiercial waste incinerator.
This awareness about
the environmental devastation caused by incinerators is spreading fast in the
West, and finding more
and more eager ears and
attempts are being made
to search for alternatives.
This anti-incineration movement has led to several international bans. For instance, in 1985, the
government of Sweden implemented a
two year moratorium on the construction of all new incinerators. In May
1992, the company, Chemical Waste
Management, tried unsuccessfully to
persuade communities in Mexico to
accept proposals for hazardous waste
incinerators. These proposals were met
with local opposition. In March 1995,
an ecological group in Chihuahua,
Mexico, protested against a proposal to
build a municipal waste-to-energy
incinerator, promoted by a Canadian
Company -Alberta Special Waste
Management.
In the us, since 1985, two hundred
and eighty incinerator proposals have
been struck down. Despite this, the us
still has twice the hazardous waste
incineration capacity than what is good
for it. There is a five-year moratorium
on waste incineration in Berkley,
California. Waste incineration has been
banned within city borders by the
Philadelphia city council. There was a
law suit against the internal revenue service for allowing the use of tax exempt
bonds for mass burn incinerator plants
in Vermont, us. All the above sited
examples are evidence to the fact that
there is definitely ananti-incineration
movement in the Organization for
Economic Cooperation and Development countries. It is time cue thought
out whether we should buy from the
West what they do not want in their
own land.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.