POPULATION, WASTE AND CHEMICALS
aste is an inevitable by-product of most human activities. People have been generating and discarding materials since hunter-gatherers threw bones and vegetable remains outside their caves. For many hundreds of years those wastes consisted exclusively of matter which biodegraded easily (such as vegetable and human wastes), or were inert (such as bones and wood ash). Given the relatively small population, the quantities of waste were minor and could be readily absorbed by the environment; indeed they had value in fertilizing the soil. [Add]
As the global population grew, and urban and industrial development accelerated, the opportunities to dispose of materials, including biodegradable ones, diminished while the quantities and nuisance value of wastes increased. Society now has large volumes of waste to deal with: in the United Kingdom, for example, more than 500 million tons of waste are generated each year, of which some 30 percent are mineral wastes, 20 percent industrial, 40 percent agricultural and 5 percent municipal. A sometimes inordinate focus on household waste has often disguised the much larger volumes generated by up-stream activities such as extraction, manufacture and distribution: it is often claimed that for every ton of finished product, ten tons of wastes are created. [Add]
Laws to raise waste management standards were first introduced at the beginning of the 20th century, and today there is a plethora of such regulation. As well as protecting public health and reducing local nuisance, these laws are increasingly aimed at protecting the wider global environment. Waste is no longer a local issue. There are global concerns about the consumption of finite resources and the impacts of their acquisition, as well as the effects of waste management and the transboundary nature of pollution. [Add]
Certain wastes -- such as polychlorinated biphenyls (PCBs), now phased out, and those from the nuclear industry -- take many years to reach a state where they pose no further threat. Concern about long-term harm has influenced disposal methods. We have learned, in theory, how to manage landfill sites to contain leakage, and how to seal radioactive waste in concrete tanks for safe, long-term storage. We have developed combustion technologies to minimize emissions, and found ways to clean those emissions. Yet despite the many advances, disposing of waste is still problematic. Some potential disposal sites are ruled out by geological factors and some by their distance from the point of arising, but almost all are opposed by nearby residents. Proposals to site a recycling collection point attract as much opposition as those to construct a high-tech incinerator. We all want the goods and services which industrialized society provides -- from power supplies to computers, fast food to vitamin pills -- yet we do not want the resulting waste to affect us as individuals. This is exacerbated by mistrust of waste management systems and the risk of accident. [Add]
Industrial waste reflects not only the type of industry, but also how efficiently it is operated, and whether "clean technologies" are adopted. It is estimated that 26 percent of Europe's waste comes from manufacturing. In 1996, the United Kingdom generated 56 million tons of manufacturing waste . These quantities are diminishing, but not fast enough to counteract the rises caused by increased consumption. Pressure for industry to reduce wastage comes from both internal and external economic drivers. Producer responsibility initiatives -- already in place or proposed for a range of goods from batteries and packaging to vehicles and electronic equipment -- make industry responsible for its products after use, and should result in fewer harmful components, as well as design decisions which will make disassembly and recycling easier. [Add]
Industrialization and level of affluence influence both the composition and quantity of waste generated by society. Research shows that in lower income regions of the world (such as Jakarta, Indonesia or Lucknow, India) 73 to 96 percent of the typical family's waste comprises food and biodegradable material, while in the higher income area of Brooklyn, New York, that figure is 26 percent . Waste densities vary too: in high income countries, waste density is lower because it contains more lighter materials and manufactured goods, more paper and less food waste.
The link between affluence and municipal waste generation is surprisingly close: a 40 percent increase in the GDP of countries belonging to the Organisation for Economic Co-operation and Development (OECD) since 1980 has been accompanied by the same percentage growth in municipal waste. The OECD predicts that there will be a further 70 to 100 percent increase in GDP in its region by 2020. Unless the link between waste generation and GDP is severed, there could be a commensurate increase in waste. This is likely to be further exacerbated by certain social trends, such as the increase in single-person households due to higher divorce rates and the ageing population, particularly in the developed world. As the developing world industrializes and grows more affluent, it too can be expected to increase waste generation. [Add]
How can the links be broken? Technological developments in materials have already helped to reduce waste: food cans and glass milk bottles are each half the weight they were 50 years ago. This, alongside new materials, is reflected in the composition of household waste. In the United States, for example, the combined percentage of glass and metals in the waste stream diminished from 22 percent in 1970 to around 16 percent in 1990. Plastics rose from 2 percent to 9 percent, while paper and card remained fairly constant at around 38 percent . By contrast, paper makes up just 5 percent of the waste in Ghana .
Trial schemes which charge householders for the waste they produce have raised awareness, although they have also thrown up a few new problems, such as wastes being dumped by roadsides to avoid the charges. The Swiss Environment Ministry reports that another method of avoiding waste charges -- the burning of domestic refuse in gardens or fireplaces -- is now the country's biggest cause of dioxin pollution. While the national emissions of dioxin from municipal incineration facilities are just 16 grams per year, uncontrolled burning of waste by householders emits between 27 and 30 grams of dioxin each year, despite the fact that only 1 to 2 percent of Switzerland's municipal waste is burned illegally, while 46 percent is burned in properly managed plants. [Add]
Sustainable development policies require us to take a more holistic view of waste and resources. We need to change attitudes, and to husband resources more carefully, particularly those which are finite. Observing the proximity principle and providing waste treatment and disposal facilities within a region's boundaries can do a great deal to reduce the environmental impact of managing waste. [Add]