Environmental and Health Impact of Solid Waste Management Activities

By R.E. Hester, R. M. Harrison

The Royal Society of Chemistry

Copyright © 2002 The Royal Society of Chemistry
All rights reserved.
ISBN: 978-0-85404-285-2

Contents

Overview of Waste Management Options: Their Efficacy and Acceptability Kit Strange, 1,
1 Introduction, 1,
2 Key Issues, 1,
3 What Is Waste?, 2,
4 How Is Waste Managed?, 7,
5 Recycling, 33,
6 What Is Integrated Waste Management?, 34,
7 Trends in Waste Management, 39,
8 Public Attitudes, 43,
9 Conclusions, 50,
Health Risks of Materials Recycling Facilities Toni Gladding, 53,
1 Introduction, 53,
2 Previous Research Concerning Waste Handsorting, 58,
3 A Further Study on MRFs, 67,
4 Conclusions, 71,
5 Acknowledgements, 72,
Microbial Emissions from Composting Sites Jillian R. M. Swan, Brian Crook and E. Jane Gilbert, 73,
1 Introduction, 73,
2 Bioaerosol Components, 78,
3 Potential 111 Health Effects among Compost Workers, 84,
4 Compost Site Case Studies, 86,
5 Ill Health Case Studies, 96,
Health Effects and Landfill Sites Andy Redfearn and Dave Roberts, 103,
1 Introduction, 103,
2 Overview of Epidemiological Studies, 104,
3 Adverse Birth Outcomes, 116,
4 Theoretical Basis of Purported Effects, 129,
5 Summary, 139,
Emissions from Solid Waste Management Activities Paul T. Williams, 141,
1 Introduction, 141,
2 Waste Landfill, 141,
3 Incineration, 153,
4 Other Waste Treatment Processes, 165,
Health Impacts of Waste Incineration Ari Rabl and Jo V. Spadaro, 171,
1 Introduction, 171,
2 Emissions, 174,
3 Dispersion and Peak Concentration, 179,
4 Health Impacts and Costs, 182,
5 Monetary Valuation, 185,
6 Calculation of Damage, 186,
7 Damage Costs per Kilogram of Pollutant, 189,
8 Damage Costs per Kilogram of Waste, 189,
9 Conclusions, 192,
10 Acknowledgements, 193,
Methodological Issues Related to Epidemiological Assessment of Health Risks of Waste Management Helen Dolk, 195,
1 Introduction, 195,
2 The Design of an Epidemiological Study, 196,
3 Disease/Health Measurement, 197,
4 Exposure Measurement, 199,
5 Confounding, 204,
6 Statistical Considerations, 207,
7 Criteria for Causation, 209,
8 Use of Epidemiological Studies in Risk Management, 210,
Subject Index, 211,

CHAPTER 1

Overview of Waste Management Options: Their Efficacy and Acceptability

KIT STRANGE

1 Introduction

Managing solid wastes in society has been a challenge for as long as people have gathered together in sufficient numbers to impose a stress on local resources. In bygone centuries (and nowadays in poorer countries) waste from homes and industries could be dealt with simply by hauling it to crude dumps where it could be buried, eaten by animals and burned.

Household waste and other waste streams needed to be removed from the human environment to avoid nuisance and public health problems, and the wider environment provided an ample sink for these negative effects of human life. Growth in population and in individual prosperity have since combined to put greater pressure on the environment, at the same time as permitting a growth in people’s appreciation of that environment. Consequently waste management policy and practice in industrialised countries developed rapidly in the second half of the 20th century, to ensure that, while public and occupational health risks are minimised, environmental resources are protected.

Since the 1980s one of the driving forces in shaping waste policy, along with many other aspects of life in society, has been the over-arching goal of sustainable development. Within this broader ambition, approaches to waste management have changed, embracing the social, economic and environmental dimensions of sustainability. In practical terms, sustainable waste management has been equated with integrated waste management, the judicious application of a range of options to achieve a broadly optimal system of waste management and resource recovery.

2 Key Issues

The main challenge for a modern, industrial country is to break the historic link between waste creation and wealth creation. Over the years, per capita waste arisings and wealth (expressed as GDP) have appeared to grow inexorably – with waste production outstripping economic growth. Total reported waste generation within the EU and the European Free Trade Area increased by 10% between 1990 and 1995. Over this period, economic growth was 6.5% in constant prices. The EEA has demonstrated a close correlation between economic activity and municipal waste generation.

Although limited data hinder the development of projections for future waste trends, it is considered that most waste streams will probably increase over the next decade.

The European Union’s 5th Environment Action programme Towards Sustainability set a target of stabilising municipal waste generation at the 1985 level of 320 kg/capita/annum by 2000. However, there has been little progress and it is clear that this was not met. In fact MSW generation within the EU averaged 400–450 kg per person in 2000, representing a growth of about 30% between 1985 and 2000 (an average annual growth of about 2%). The European Union’s 6th Environment Action programme Environment 2010: our future, our choice changed from capping individual waste generation rates to setting targets for landfill diversion. This is arguably easier to achieve and is certainly easier to measure.

It remains very difficult to improve the way society uses resources, improving efficiency and reducing the environmental impacts associated with the flow of unwanted materials and energy. This is not because of any particular technical barriers, but is rather a matter of costs and acceptability. While holes in the ground are relatively abundant, more sustainable waste management options can seem unreasonably expensive alternatives, particularly when there is no agreement over who should bear those costs.

3 What Is Waste?

Definitions

The report focuses generally on municipal solid waste (MSW). The definition of MSW varies, but typically includes waste arising from private households to that collected by or on behalf of local authorities from any source. MSW therefore includes a proportion of commercial and non-hazardous industrial waste. Depending on the country, the definition can include some or all of:

• household wastes (collected waste, waste collected for recycling and composting, and waste deposited by householders at household waste disposal sites)

• household hazardous wastes

• bulky wastes derived from households

• street sweepings and litter

• parks and garden wastes

• wastes from institutions, commercial establishments and offices

In Britain, municipal waste is defined as waste collected by, or on behalf of, local authorities and includes all the waste types listed above, although the trade waste component tends to be limited. In most countries, municipal waste is taken to be a broader and more encompassing definition than simply household solid waste.

Depending on definitions, a study by the Dutch Environment Ministry (VROM), in 1997, found that the ratio of household waste to municipal waste varies dramatically from 45% (Norway) to 84% (Germany). It should be recognised that municipal waste is a management concept and since the extent of municipal collection activities in the commercial sector varies widely across the countries surveyed, data and information are unlikely to be directly comparable in a number of cases.

MSW is a small fraction of all solid wastes. The UK generates more than 400 million tonnes per annum (Mtpa) of solid waste, in the following approximate proportions:

• Agriculture 19%

• Mining and quarrying 18%

• Construction and demolition 17%

• Industrial 16%

• Dredged spoils 12%

• Sewage sludge 8%

• MSW 7%

• Commercial 4%

In many ways MSW is the most significant waste stream because it stems from us all, reflecting our lifestyle choices, our consumption and resource recovery decisions.

Waste policies have tended by rely on setting targets which oblige countries or local authorities to recover or recycle specified fractions of waste, or to divert material from disposal to landfill. Inevitably this approach requires decisions on the relative merits of the waste management alternatives. This has become established as the waste management hierarchy, a formal order of preference which guides policy-makers.

The Waste Management Hierarchy

Waste management is a complex subject, made up of many component parts. It can be easy to lose sight of the ‘big picture’. European waste management is particularly challenging: environmental protection must be achieved without distorting the European internal market. There is no blueprint which can be applied in every situation but the EU has firm principles upon which its approach to waste management is based.

• prevention principle – waste production must be minimised and avoided where possible

• producer responsibility and polluter pays principle – those who produce the waste or contaminate the environment should pay the full costs of their actions

• precautionary principle – we should anticipate potential problems

• proximity principle – waste should be disposed of as closely as possible to where it is produced

These principles are made more concrete in the 1996 EU general strategy on waste which sets out a preferred hierarchy of waste management operations:

1. prevention of waste

2. recycling and reuse

3. optimum final disposal and improved monitoring

The strategy also stresses the need for:

• reduced waste movements and improved waste transport regulation

• new and better waste management tools (e.g. regulatory and economic instruments)

• reliable and comparable statistics on waste

• waste management plans

• proper enforcement of legislation

Nowadays it is more often recognised that, although prevention is clearly the ideal option, there are sound reasons why it is not always sensible to specify precisely an order of waste management preferences. A rigid approach has limitations:

• the hierarchy has little scientific or technical basis (there is no scientific reason, for example, why materials recycling should always be preferred to energy recovery)

• the hierarchy is of little use when a combination of options is used (the hierarchy cannot predict, for example, whether biological treatment combined with thermal treatment of the residues would be preferable to materials recycling plus landfilling of residues)

• the hierarchy does not address costs (and so cannot help assess affordability)

However, the hierarchy can be used within an IWM philosophy as a reminder of the waste management options available to the decision-maker.

Composition

The composition of MSW is variable, depending on a range of factors. Household waste reflects population density and economic prosperity, seasonality, housing standards and the presence of waste minimisation initiatives (for example home composting). The prevalence of open fires in the home will affect the levels of combustible materials in the waste stream. Commercial waste will be influenced by the nature of the commerce. The composition of MSW will also depend on the specific definition of MSW being applied. The Resource Recovery Forum published a report which showed the results of extensive analyses of one source of household waste, showing the detailed breakdown of residual waste and materials recovered for recycling (Table 1).

Eurostat reports that data availability on waste composition is generally very poor and difficult to compare, not least because the characterisation techniques may vary from country to country. Because of this, the method used to assess the weight of the various fractions may influence the results due to the fact that objects containing various materials may or may not be assigned to a single category. The compositions reported (see Table 2) may not always refer to the total amount of municipal waste generated which should – but does not always – include all the waste fractions separately collected for recycling and recovery operations.

Waste Arisings

The rate at which individuals create waste is at least as variable as the composition of the waste generated. The average European now creates more than half a tonne of municipal solid waste each year, and arisings are generally stable, although growth is still taking place in some countries.

The European agency Eurostat publishes waste and other environmental statistics, which indicate that the trend in municipal solid waste arisings continues to grow, accounting for approximately 190 million tonnes per annum (Mtpa) in the mid-1990s, averaging 575 kg per person per annum (see Figure 1).

4 How Is Waste Managed?

Essentially, the final management option for residual waste is disposal to landfill. Everything else might be viewed as some form of pre-treatment or waste avoidance. However, it is clear that all of the alternative management options have a role to play, to help minimise the amount of material which can be said to have been wasted. Indeed, some optimistic policy-makers do not regard even landfill disposal as an ultimate waste of resources, preferring to regard this as a long-term storage element of a wider Zero waste policy.

The range of options available once waste is created is limited to recovering materials and/or energy resources before the final, useless residues are landfilled. The techniques applied depend on the materials in the waste, the waste management systems available locally or regional and the market opportunities. The selection depends particularly on the established waste management policy. Treatment methods are used to reduce the amount of residual waste for disposal, and to achieve one or more of the following goals:

• reduce the potential environmental impacts of the waste

• separate and recovery materials or energy

• reduce transport costs

• reduce the

• volume of landfill needed

• minimise overall costs

Waste management options after generation and before final disposal comprise:

• waste minimisation

• collection and sorting

• re-use

• recycling

• composting

• anaerobic digestion

• energy recovery (incineration or other more advanced thermal treatment techniques)

• incineration (without energy recovery)

Arguments over the relative merits of management options between prevention and disposal have been loud and vigorous, although during the late 1990s there were significant signs of rapprochement between the different camps. Although local circumstances may alter the priorities, it is generally true that the main purpose of a waste management policy is to reduce the scope for waste to harm the environment or public health. The European Commission has described the range of environmental impacts from managing MSW, as shown in Table 3.

It is clear from many sources that different countries elect to manage waste in different ways, or rather display different sets of preferences as alternatives to landfill. A study undertaken for the Resource Recovery Forum yielded the results shown in Figure 2, which shows that landfill dependency ranges by an order of magnitude.

Waste Minimisation

Waste minimisation, prevention or avoidance is the most important management technique to be applied to solid wastes, because waste which is avoided needs no management and has no environmental impact.

General recommendations, while helpful in theory, often contribute little in any individual case, over and above giving pointers as to possible waste reduction routes. In order to successfully reduce waste volumes, it is first necessary to establish the composition of that waste, and the reasons which prompted its creation. In a domestic situation, those reasons may include or be dictated by life style, for example if both parents in a household are working full time, necessitating the purchase of more convenience foods, or if there is a young baby in the family using disposable nappies. The growing tendency in some countries for smaller households increases the likely quantities of wastes created. For example one study showed that single-person homes can create around 120 kg food waste each year. By contrast each person in a two-person household creates only 85 kg food waste pa. In a three-person, home this figure falls to 50 kg per person per year. In a commercial situation, some waste may be the result of delivery policies set by a central supply system, or stem from choices made years before on types of machinery, requiring considerable investment in new equipment to change.

Definition. While some consider the diversion of waste materials into recycling to be waste minimisation, as this reduces the amount of waste going for final disposal, the original intent of the term was to reduce to a minimum the amount of waste being generated. The OECD has developed a broad definition of waste minimisation, encompassing the following three elements, in this order of priority:

• preventing and/or reducing the generation of waste at source

• improving the quality of the waste generated (e.g. reducing the hazard)

• encouraging re-use, recycling and recovery

Home composting schemes, where householders themselves turn kitchen and garden wastes into compost, can be considered waste minimisation, but all other procedures which require handling of wastes such as collection for recycling, while reducing pressure on disposal facilities, are not actually reducing the amount of waste generated. That reduction could be achieved through changed manufacturing procedures, or even a change in the type or combination of materials used, enabling production scrap to immediately be returned to the beginning of the manufacturing line, so that it never reaches the stage of being considered a waste.

Resource optimisation. It is easy to think narrowly of waste as a solid product left over at the end of a process or action, but it would be wrong to concentrate on reducing the amount of solid waste produced, to the exclusion of considerations about, among other things, wastage of energy or water. It is as wasteful to use several gallons of water unnecessarily, or to drive cars when one could walk or cycle, or to consume energy thoughtlessly, as it is to discard newspapers, cans or empty wrappings.

(Continues…)Excerpted from Environmental and Health Impact of Solid Waste Management Activities by R.E. Hester, R. M. Harrison. Copyright © 2002 The Royal Society of Chemistry. Excerpted by permission of The Royal Society of Chemistry.
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