Alternatives to the waste mountain created by current waste strategies.
Alternatives |
Waste management alternatives |
Medical waste |
Hospital products |
Disinfection |
Autoclaving |
Cost benefits of autoclaving |
Microwave disinfection |
Superheated steam |
Hazardous waste |
Toxic use reduction |
Cement kilns
Municipal and hospital waste incinerators are the largest dioxin
sources in industrial countries. PVC plastic is probably the most
significant source of dioxin generating chlorine in these
incinerators.
Incinerators that burn hazardous waste from industry are also
point sources of dioxin.
Strategies to prevent generating incineratable waste streams
currently exist by:
· Toxic use reduction planning within industries;
· Waste reduction and alternative forms of sterilisation in
hospitals; and
· Efficient reduction, recycling and compost actions at
community level for
household waste.
Incinerators and cement kilns that burn hazardous waste will
never solve toxic waste problems. A clean production approach,
which substitutes safe materials and processes to stop the
generation of hazardous waste in the first place, is needed.
Alternatives to municipal waste incineration
Municipal and biomedical waste incinerators, are the largest
dioxin sources in industrial countries, according to the US
EPA.
Although it only accounts for approximately 0.5 percent of
municipal waste by weight, PVC provides over 50 percent of
available chlorine - the element essential to dioxin formation.
According to the majority of incineration studies, when all
other factors are held constant, there is a direct correlation
between input of PVC and output of dioxin. For this reason the
Danish government policy is to avoid the presence of PVC in
incinerators.
"Cleaner production is as much about attitudes, approaches and
management as it is about technology. This is why it is called
cleaner production and not cleaner technology." Cleaner Production
in the Mediterranean Region, 1995.
If all the PVC and chlorinated wastes were eliminated from the
waste stream, incineration would still be a poor solution due to
high costs, loss of jobs in the recycling industry, lost profits
from secondary resale and on-going contamination from heavy metal,
hydrocarbon and other air emissions.
Cost effective and eco-efficient waste management alternatives to incineration exist
Glass, metals and paper can be easily recycled and reused.
Organic waste fractions can be composted at household or community
level. Some plastics such as polyethylene and polypropylene can be
efficiently recycled if collection and recycling systems are based
within the region.
Recycling is also profitable. A ban on incinerators, legislated
in 1992 in the province of Ontario, Canada, stimulated job creation
and the price of secondary materials.
A highly successful recycling programme is running in Curitibi,
Brazil since 1989. Ten thousand families participate in the
"Garbage that is not Garbage" programme receiving two kilos of food
for every four kilos of recyclable garbage collected and delivered
to the mobile units.
The programme was implemented to foster the separation of
organic from inorganic garbage as part of the city's environmental
programme. Even admittance to the municipal open air shows requires
bringing a bag for recycling rubbish. Approximately 60 tonnes of
paper are recycled every day equivalent to 1,200 trees.
The goals for the future are to transform Curitiba into a centre
of excellence in the areas of urban planning and transportation and
demonstrate the success of good city planning in developing
countries.
An analysis of recycling potential including composting found
that 72.8 percent of waste reclamation was possible. The financial
costs of incineration (even with energy recovery) was calculated to
be 6,000 pesetas/tonne compared to 2,325 pesetas/tonne if materials
were recycled. Implementation could achieve a 60 percent beneficial
use within five years and solve the country's escalating waste
problem.
A study, by the Centre for the Biology of Natural Systems in New
York, US in 1996, to examine the costs and benefits of eliminating
dioxin sources from all combustion processes in the Great Lakes
region of North America. The study found that replacing all
municipal waste incinerators in the region with intensive recycling
programmes would result in approximately US$530 million annual
savings.
The consequences of closing all the 52 Great Lakes garbage
incinerators and creating programs of intensive recycling capable
of diverting the same tonnage of waste that is currently burned
involves an increase in collection costs and an increased education
cost to the municipalities. But this is balanced against the net
income from processing and marketing collected recyclables, the
savings from avoiding disposal costs and paying off the debt for
the incinerator.
The study estimated that 6,100 jobs would be created from
additional collection and processing jobs after deducting job
losses at incineration closures. Further job increases of 21,000
are predicted if the additional recycled materials are used by
current and new manufacturing firms within the region.
A 1991 study by the Worldwatch Institute calculated the number
of jobs per one million tonnes of waste processed in New York
City.
Type of waste disposal/Number of jobs
Landfill - 40-60
Incinerators - 100-290
Mixed waste composting - 200-300
Recycling - 400-590
Recycling is not the answer to waste reduction however. We need
to reduce our use of packaging and products and advocate reusable,
returnable packaging and better product design for durability and
reparability.
Alternatives to medical waste incineration
In medical waste incinerators, the dominant chlorine donor is
PVC plastic, which enters these facilities as packaging and in many
disposal medical products. An estimated 9.4 percent of all
infectious waste is PVC, and virtually all available chlorine fed
to medical waste incinerators comes from PVC.
In reality there are dioxin-free means of disposing of 99.7
percent of the medical waste stream. Because medical waste
incinerators are a major point sources of dioxins some countries
have brought in more stringent regulations. This has resulted in
many hospitals closing their own on-site incinerator and shipping
waste to a commercial incinerator with more pollution control
devices.
However, this is increasingly seen as an inadequate solution.
Increasingly hospitals in Austria, Germany and Denmark are reducing
the amount and nature of wastes by switching to reusables, which
can be sterilised.
Substitution of PVC products go with programmes to prevent waste
and separate for recycling. Reasons for phasing out PVC in these
hospitals: municipal incineration plants either did not accept
wastes where the chlorine content exceeded the determined
percentage, or would do so only at a considerably increased price;
incineration plants had to be closed due to more stringent emission
regulations; and repeated complaints from the community.
Other reasons exist to substitute PVC products within hospitals.
Medical objections against the use of PVC are mainly based on the
migration of the plasticiser DEHP.
It is soluble in fat-containing fluids such as blood and may
cause diseases of the liver, skin and cardiovascular system. Animal
experiments have shown a significant increase in liver tumours when
DEHP is added to the food of mice and rats. For this reason DEHP
was classified as "carcinogenic in animal experiments" and for lack
of adequate epidemiological studies in human beings as "possible
human carcinogen". Recent evidence points to its hormone disrupting
potential.
Currently there are often increased costs for PVC alternatives
(often 20-30 percent more expensive). However these costs must be
balanced against the cost of ongoing incineration fees and dioxin
emissions.
Non PVC hospital products
In general, 85 percent of the total medical waste stream in
hospitals consists of the same mixture of discarded paper, plastic,
glass, metal and food waste that is found in ordinary household
waste. The remaining 15 percent is defined as infectious and these
wastes must be sterilised before disposal.
A small percentage of this waste or 0.3 percent of the total
medical waste stream, can only be incinerated, in part for cultural
or aesthetic reasons, but also because it is difficult to sterilise
in any other way. Thus there are dioxin-free means of disposing of
99.7 percent of the medical waste stream. Non hazardous waste can
be recycled within a household waste recycling plan.
Alternative disinfection
For disposing of infectious waste there are several alternative
dioxin-free methods that are cost comparative.
Three of these are autoclaving, microwave disinfection and
superheated steam sterilisation.
Autoclaving
An estimated 45 percent of infectious medical equipment from
Western hospitals is already reused through autoclaving.
This is basically steam sterilisation, which encourages the
reuse or recycling of medical equipment. Autoclaves are
commercially available in varying sizes from desktop to industrial
units.
The process involves heating bags of medical waste at between
120 and 165 C for 30 to 90 minutes in chambers into which
pressurised steam is introduced. The steam penetration ensures
destruction of bacteria and pathogenic micro-organisms. Waste is
reduced by an estimated 75 percent of its volume and can either be
landfilled directly or compacted further.
The autoclaved infectious waste adds to the landfill burden, but
the amount is usually less than 0.2 percent of the municipal solid
waste stream. According to a recent survey of hospitals that have
installed autoclaves, they are easier to operate than
incinerators.
Cost benefits of autoclaving
A 1996 study by the Centre for the Biology of Natural Systems in
New York examined the annual operating costs of hospital
incinerators in the Great Lakes Region of North America and found
that autoclaving was more profitable.
Autoclaving is the most profitable investment unless there are
no regulations at all on incineration emissions. Further assessment
was made of the costs to hospitals of converting to autoclaves
including paying off the debt on the original purchase of an
incinerator. In this scenario conversion costs (US$2.9 million) are
still cheaper than the annual operating cost of incineration with
mandatory emission upgrading (US$3.4 million per year).
Microwave disinfection
Microwaving is economically competitive, versatile and studies
in Europe have shown virtually no emissions since the internal
heating system is closed. Consequently there is no need for
pollution control devices. Microwave disinfection relies on
treating hospital waste with moist heat and conventional microwaves
at temperatures of 940C. The equipment can be installed on or off
site in stationary or mobile units. The remaining
residues, which have been reduced by 80 percent in volume, can
be landfilled
Superheated steam sterilisation
This technology comprises a heated shredder and sterilisation
unit. In the shredder, organic liquids are vaporised and solids
reduced to gas by super-heated steam at temperatures between 500
and 700C.
Medical equipment is melted into a sterile mass in under an
hour. Remaining residues are cooled and dropped into a collection
bin or ground in a heated shredder. The process has been shown to
reduce medical waste by 50 to 80 percent of its original
volume.
Alternatives to hazardous waste incineration
European researchers estimate that 70 percent of all current
waste and emissions from industrial processes can be prevented at
source by using technically sound and economically profitable
procedures.
No country should contemplate a commercial hazardous waste
incinerator without a national programme of cleaner production.
Policy measures to achieve this have been well documented by UN
agencies and cleaner production initiatives have achieved
significant results particularly within small and medium scale
industries.
Once an incinerator is built, ongoing toxic waste generation is
legitimised and there is little incentive to investigate process
changes within industry even if cleaner production methods are more
profitable. For this reason, mandatory toxic use reduction plans
should be prepared by each facility currently generating toxic
waste.
Benefits of toxic use reduction - Massachusetts, USA
Massachusetts in the US has achieved significant reduction of
hazardous waste through mandatory company planning. This
legislation and training programme has become a model for pollution
prevention activities around the world.
The Toxic Use Reduction Act (TURA) was passed in 1989. The goal
of the legislation is to develop toxics use reduction as its
primary tool for industrial pollution control while enhancing the
competitive position of Massachusetts enterprises. The first goal
is to reduce toxic waste generation by 50 percent through toxics
use reduction over a 10 year period (1987-1997).
Under TURA firms that use any of a list of approximately 800
chemicals in quantities that annually cross a minimum threshold
must:
· Annually report publicly on the amount of chemical used and
released; and
· Pay an annual fee prepare a plan (updated every two years) on
how to
reduce or eliminate the use of those chemicals that is certified
by a licensed Toxics Use Reduction Planner.
Between 1990 and 1993 all firms cut their toxic by-product
(waste) by 14.5 percent and plan to generate 23 percent less waste
in 1998.
Total volume of listed toxic chemicals in the state dropped by
six percent within these three years. Of the 29 firms applying for
awards in toxics use reduction, together they had eliminated the
use of 2,870 tons of toxic chemicals, reduced 750 tons of hazardous
wastes and saved US$44 million per year.
Alternatives to other combustion sources of dioxin - cement kilns
Increasingly, cement kilns are burning hazardous waste as fuel
thereby generating dioxins in air emissions and ash. Cement
products are now contaminated with heavy metals and dioxins. A
phase out of incinerable waste streams is possible via toxics use
reduction legislation.
The Centre has done the economic costs of converting these
cement kilns back to fuel for the Biology of Natural Systems in
1996. The study found that the added expected income from burning
hazardous waste in cement kilns is likely to be less than the model
estimates due to a declining market share.
This would enable kilns to resume former fuel burning of coal,
coke, oil or natural gas, as currently practised by three quarters
of the kilns in the region. However instead of receiving a tip fee
(which in 1993 amounted to US$68 million), the 9 cement kilns in
the region would then pay for the normal fuel (about US$9 million
per year) amounting to an increase of approximately US$77
million.
At the same time, the transition results in a payroll saving
since additional employees that handle the hazardous material are
no longer needed. Furthermore the kiln could avoid the operational
costs of installing control devices and more importantly would not
generate dioxin-contaminated emissions and wastes.