Waste as a driver of change

Part 1: The nature of the problem 

            and why we have it

Introduction:

Fig.1 Humans use the term “waste” to describe materials 

that have been used but are no longer wanted.

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

Fig. 2 Territory size shows relative proportion of the

 world's population living there.

Fig. 3 Territory size shows proportion of total

 global municipal waste generated there.

Calculating the amount of waste generated on the global scale presents several issues. There are numerous ways to define, describe, and monitor waste. Some countries, on the other hand, lack reporting of any kind. These factors together present significant issues when attempting to generate and examine comparable data from one country to the next. A recent report1 estimates that 1.2 bn tonnes of municipal waste were collected worldwide in 2004. The main producers of municipal waste are the United States and Europe, each collecting more than 200M tonnes of waste per annum. The US seems to be the worst offender, with over 700kg of domestic waste per person generated every year. The US is closely followed by Australia and parts of Western Europe, with 600-700kg per year. In contrast, the average resident of Nairobi in Kenya generates only 220kg per year; in Mumbai in India, annual waste generation is as low as 120kg per person.

Fig. 4 Territory size shows proportion of total

global municipal waste recycled there.

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).

Fig. 5 Waste and wealth: links between 

increasing GDP and waste generation.

Waste is generated in many ways, but its composition and volume largely depend on country specific consumption patterns and industrial and economic structures. It has been widely observed that the generation and collection of waste are globally linked to both GDP (gross domestic product) and urbanization. The economies of developed countries depend on the consumption of goods and services to drive the economic growth seen as fundamental to meeting society’s needs.

Fig 6. Global household expenditure.

This leads to the increasing production and use of natural resources that are required to keep consumers spending. Unsurprisingly, as consumption increases, so does waste generation (Fig 5). Future population projections indicate that the situation is likely only to get worse, with a suggested 9bn people living on the planet by 2050, and there are no signals to suggest that global levels of consumption will decrease in the near future (Fig 6).

What are we producing?

Fig. 7 Composition of municipal solid waste 

(MSW) in the USA and Uganda (%).

Only 75 years ago, people were living in a pre-plastic, pre-chemical, and pre electronic era. Humanity’s waste was a much less volatile commodity than it is today. As with total volume generated, the composition of waste is also strongly linked to a population’s wealth. As GDP increases and people migrate from rural to urban environments, waste streams become more sophisticated, containing a much lower proportion of biodegradable food waste and far more plastics, metals, glass, and toxic products that are increasingly difficult to manage and dispose of safely. An individual living in an emerging country with limited contact with Western society produces a domestic waste stream that can be almost entirely composted (Fig. 7). It is estimated that in Uganda approximately 82% of the waste consists of food, vegetable or garden matter. In rich countries the opposite is the case, with the amount of compostable waste dropping to approximately 31% and the remainder comprising man-made products.

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.

Fig. 8 What is e- waste?

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.

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.