Over the course of the twentieth century, growing recognition of the environmental and public health impacts associated with anthropogenic activities (discussed in the chapter Environmental Health Hazards) has prompted the development and application of methods and technologies to reduce the effects of pollution. In this context, governments have adopted regulatory and other policy measures (discussed in the chapter Environmental Policy) to minimize negative effects and ensure that environmental quality standards are achieved.
The objective of this chapter is to provide an orientation to the methods that are applied to control and prevent environmental pollution. The basic principles followed for eliminating negative impacts on the quality of water, air or land will be introduced; the shifting emphasis from control to prevention will be considered; and the limitations of building solutions for individual environmental media will be examined. It is not enough, for example, to protect air by removing trace metals from a flue gas only to transfer these contaminants to land through improper solid waste management practices. Integrated multimedia solutions are required.
The Pollution Control Approach
The environmental consequences of rapid industrialization have resulted in countless incidents of land, air and water resources sites being contaminated with toxic materials and other pollutants, threatening humans and ecosystems with serious health risks. More extensive and intensive use of materials and energy has created cumulative pressures on the quality of local, regional and global ecosystems.
Before there was a concerted effort to restrict the impact of pollution, environmental management extended little beyond laissez-faire tolerance, tempered by disposal of wastes to avoid disruptive local nuisance conceived of in a short-term perspective. The need for remediation was recognized, by exception, in instances where damage was determined to be unacceptable. As the pace of industrial activity intensified and the understanding of cumulative effects grew, a pollution control paradigm became the dominant approach to environmental management.
Two specific concepts served as the basis for the control approach:
- the assimilative capacity concept, which asserts the existence of a specified level of emissions into the environment which does not lead to unacceptable environmental or human health effects
- the principle of control concept, which assumes that environmental damage can be avoided by controlling the manner, time and rate at which pollutants enter the environment
Under the pollution control approach, attempts to protect the environment have especially relied on isolating contaminants from the environment and using end-of-pipe filters and scrubbers. These solutions have tended to focus on media-specific environmental quality objectives or emission limits, and have been primarily directed at point source discharges into specific environmental media (air, water, soil).
Applying Pollution Control Technologies
Application of pollution control methods has demonstrated considerable effectiveness in controlling pollution problems - particularly those of a local character. Application of appropriate technologies is based on a systematic analysis of the source and nature of the emission or discharge in question, of its interaction with the ecosystem and the ambient pollution problem to be addressed, and the development of appropriate technologies to mitigate and monitor pollution impacts.
In their article on air pollution control, Dietrich Schwela and Berenice Goelzer explain the importance and implications of taking a comprehensive approach to assessment and control of point sources and non-point sources of air pollution. They also highlight the challenges - and opportunities - that are being addressed in countries that are undergoing rapid industrialization without having had a strong pollution control component accompanying earlier development.
Marion Wichman-Fiebig explains the methods that are applied to model air pollutant dispersion to determine and characterize the nature of pollution problems. This forms the basis for understanding the controls that are to be put into effect and for evaluating their effectiveness. As the understanding of potential impacts has deepened, appreciation of effects has expanded from the local to the regional to the global scale.
Hans-Ulrich Pfeffer and Peter Bruckmann provide an introduction to the equipment and methods that are used to monitor air quality so that potential pollution problems can be assessed and the effectiveness of control and prevention interventions can be evaluated.
John Elias provides an overview of the types of air pollution controls that can be applied and the issues that must be addressed in selecting appropriate pollution control management options.
The challenge of water pollution control is addressed by Herbert Preul in an article which explains the basis whereby the earth’s natural waters may become polluted from point, non-point and intermittent sources; the basis for regulating water pollution; and the different criteria that can be applied in determining control programmes. Preul explains the manner in which discharges are received in water bodies, and may be analysed and evaluated to assess and manage risks. Finally, an overview is provided of the techniques that are applied for large-scale wastewater treatment and water pollution control.
A case study provides a vivid example of how wastewater can be reused - a topic of considerable significance in the search for ways that environmental resources can be used effectively, especially in circumstances of scarcity. Alexander Donagi provides a summary of the approach that has been pursued for the treatment and groundwater recharge of municipal wastewater for a population of 1.5 million in Israel.
Comprehensive Waste Management
Under the pollution control perspective, waste is regarded as an undesirable by-product of the production process which is to be contained so as to ensure that soil, water and air resources are not contaminated beyond levels deemed to be acceptable. Lucien Maystre provides an overview of the issues that must be addressed in managing waste, providing a conceptual link to the increasingly important roles of recycling and pollution prevention.
In response to extensive evidence of the serious contamination associated with unrestricted management of waste, governments have established standards for acceptable practices for collection, handling and disposal to ensure environmental protection. Particular attention has been paid to the criteria for environmentally safe disposal through sanitary landfills, incineration and hazardous-waste treatment.
To avoid the potential environmental burden and costs associated with the disposal of waste and promote a more thorough stewardship of scarce resources, waste minimization and recycling have received growing attention. Niels Hahn and Poul Lauridsen provide a summary of the issues that are addressed in pursuing recycling as a preferred waste management strategy, and consider the potential worker exposure implications of this.
Shifting Emphasis to Pollution Prevention
End-of-pipe abatement risks transferring pollution from one medium to another, where it may either cause equally serious environmental problems, or even end up as an indirect source of pollution to the same medium. While not as expensive as remediation, end-of-pipe abatement can contribute significantly to the costs of production processes without contributing any value. It also typically is associated with regulatory regimes which add other sets of costs associated with enforcing compliance.
While the pollution control approach has achieved considerable success in producing short-term improvements for local pollution problems, it has been less effective in addressing cumulative problems that are increasingly recognized on regional (e.g., acid rain) or global (e.g., ozone depletion) levels.
The aim of a health-oriented environmental pollution control programme is to promote a better quality of life by reducing pollution to the lowest level possible. Environmental pollution control programmes and policies, whose implications and priorities vary from country to country, cover all aspects of pollution (air, water, land and so on) and involve coordination among areas such as industrial development, city planning, water resources development and transportation policies.
Thomas Tseng, Victor Shantora and Ian Smith provide a case study example of the multimedia impact that pollution has had on a vulnerable ecosystem subjected to many stresses - the North American Great Lakes. The limited effectiveness of the pollution control model in dealing with persistent toxins that dissipate through the environment is particularly examined. By focusing on the approach being pursued in one country and the implications that this has for international action, the implications for actions that address prevention as well as control are illustrated.
As environmental pollution control technologies have become more sophisticated and more expensive, there has been a growing interest in ways to incorporate prevention in the design of industrial processes - with the objective of eliminating harmful environmental effects while promoting the competitiveness of industries. Among the benefits of pollution prevention approaches, clean technologies and toxic use reduction is the potential for eliminating worker exposure to health risks.
David Bennett provides an overview of why pollution prevention is emerging as a preferred strategy and how it relates to other environmental management methods. This approach is central to implementing the shift to sustainable development which has been widely endorsed since the release of the United Nations Commission on Trade and Development in 1987 and reiterated at the Rio United Nations Conference on Environment and Development (UNCED) Conference in 1992.
The pollution prevention approach focuses directly on the use of processes, practices, materials and energy that avoid or minimize the creation of pollutants and wastes at source, and not on “add-on” abatement measures. While corporate commitment plays a critical role in the decision to pursue pollution prevention (see Bringer and Zoesel in Environmental policy), Bennett draws attention to the societal benefits in reducing risks to ecosystem and human health—and the health of workers in particular. He identifies principles that can be usefully applied in assessing opportunities for pursuing this approach.