In this final section we look at some important principles that should be applied when attempting to prevent or control pollution. Pollution prevention means avoiding or minimising the generation of wastes that produce pollutants, thereby restricting their release into the environment. Pollution control focuses on measures taken after wastes have been produced to limit the damage they may cause. It is often more difficult and expensive to control pollution after it has been released into the environment.

Which do you think is better - pollution prevention or pollution control?

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Pollution prevention is better. It is better to try and prevent pollution from being created in the first place and it is more difficult and expensive to control pollution after it has been created. However, if pollution has been created, it should be controlled.


There are many methods for prevention of pollution. For water pollution the main priority is to improve water, sanitation and hygiene (WASH) provision. If everyone has access to effective sanitation (latrines) and there is no open defecation, this will prevent contamination of the environment with human faeces. Combined with this is the need for safe drinking water to be available for all. In addition, improving hygiene behaviour and ensuring that everyone washes their hands will radically reduce the impacts on human health from biological pollutants. In practice there needs to be a coordinated approach to improving all three – water, sanitation and hygiene – which is reflected in current WASH programmes.

Air pollution can be improved by reducing the reliance on biomass fuels for domestic cooking, especially for indoor fires. Legislation to remove very old vehicles from the road or a requirement for regular maintenance and certification would also help.

For pollutants derived from solid wastes, waste optimisation should be adopted. This principle is based on the notion that, ideally, waste should not be produced in the first place. However, this primary target is not always possible and so, if waste is produced, there is a range of options for waste management that form a waste hierarchy from most desirable to least desirable (Figure 8.9).

Figure 8.9 The waste hierarchy. Waste management options are listed in order of desirability, from most desirable at the top to least desirable at the bottom.

The waste optimisation principle includes the application of what is known as the ‘3 Rs’ – reduce, reuse and recycle. Reduction refers to the minimisation of waste at source by efficient use of raw materials and changing the technology for producing items. Reuse means using an item more than once, for example, the use of plastic bottles for collecting water. Recycling refers to the use of discarded materials as raw materials that are taken back into the factory process. The use of discarded and broken bottles in a glass factory to make new glass bottles is an example of recycling. The waste hierarchy also includes recovery of materials or energy, for example through composting or incineration. Composting is a good example of recovering materials from waste organic matter that can be then used to improve soil in a constructive way rather than allowing the decomposition process to cause pollution by careless disposal.

The concept of waste optimisation is applied in industries through the process of cleaner production. Cleaner production aims to reduce the impact of industry on the environment through waste minimisation and the application of the 3 Rs, and other processes such as replacement of toxic chemicals with less toxic alternatives, and process and product modification to use less energy.

Principles for pollution control

The following principles are used to help control pollution.

Polluter pays principle

The polluter pays principle says that whoever is responsible for pollution should pay for the damage caused. It is about economic accountability. Any organisation or individual is responsible for handling and taking care of the waste they produce and should be accountable for any damage that it causes. Imagine a factory that produces many types of wastes that potentially damage the air, water and soil. The polluter pays principle encourages the factory to treat the waste before it is released. If any damage to the environment is caused by the factory waste, then the factory is liable to compensate for the loss of life, damage to health and damage to property and the environment.

Precautionary principle

For any activity, there should be an obligation not to cause harm, even if you are not sure of the outcome. For example, if a factory owner wants to discharge wastewater into a river, they should not be allowed to do so if the possible effects of the wastes are not known. The precautionary principle means you do not release any waste into the environment even if you are not certain that damage will result. It means to be cautious rather than take risks with unknown consequences.

Principle of duty of care

All citizens should be actively involved in safeguarding their environment, either by not producing any waste or by properly handling and taking care of their own waste. In other words, each citizen has an obligation or duty to make their environment clean and safe.

Last modified: Sunday, 2 October 2016, 3:28 PM