Environmental Pollution - Types, Causes, Controls and Abatement Strategies

 Environment Pollution: Types, Causes, Effects:

Environmental Pollution is not a new phenomenon, yet it remains one of the greatest threats to the health and well-being of humanity and one of the major environmental causes of death and morbidity. For example, substances such as plastic materials, heavy metals, etc., once released into the atmosphere. By natural processes, it cannot be degraded and are harmful to living organisms. In environmental pollution, pollutants originate from a source, are transported by air or water, and are dumped into the soil by human beings.

The long-term impacts of pollution are still being felt despite global attention to the issue. Day by day, our atmosphere is becoming more and more polluted due to anthropogenic activities. It is usually due to the pollutants released into the air, water, soil, etc., through many human activities. Let us examine the different types of environmental pollution.

Environment Pollution: Introduction, Causes & Types

What is Environmental Pollution?

• Environment Pollution is the addition of contaminants into the natural environment that causes detrimental effects to nature, natural resources and mankind.
• Any unnatural and negative changes in all the dimensions like chemical, physical and biological characteristics of any component of the ecosystem i.e. air, water or soil which can cause harmful effects on various forms of life and property is called environmental pollution.

What is a Pollutant?

• Any substance which causes harmful effects or uneasiness in the organisms, then that particular substance may be called as the pollutant.

The materials that cause pollution are of two types:

1. Persistent pollutants: Those pollutants which remain consistent in the environment for a long period of time without any change in its original form are called persistent pollutants. For example pesticides, nuclear wastes, and plastics etc.
2. Non-persistent pollutants: These pollutants are the opposite of persistent pollutant and break down in the simple form. If this process of breaking down is done by living organisms, then such pollutants are referred to as biodegradable pollutants.

From another perspective, pollutants can be classified as follows:

1. Primary Pollutants: Primary pollutants are those which remain in the form in which they were added to the environment for ex. DDT, Plastic
2. Secondary Pollutants: Secondary pollutants are formed due to interaction of primary pollutants amongst themselves viz. PAN by the interaction of NOx & Hydrocarbons.

According to their existence in nature:

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1. Quantitative Pollutants: These substances are already present in the atmosphere but they become pollutant when their concentration level reaches to a particular level which is above a threshold limit.
2. Qualitative Pollutants: These are man-made pollutants eg. Fungicides, herbicides etc.

According to origin:

1. Man-made Pollutants
2. Natural Pollutants

According to the nature of disposal:

1. Biodegradable Pollutants
2. Non-biodegradable Pollutants

Types of Environment Pollution:

AIR POLLUTION:

• Air pollution is the presence of one or more disadvantageous content in such quantity and for such duration, as it is catastrophic, or tend to be catastrophic, to human health and welfare, animal or plant life.
• It is the contaminants of air by the discharge of detrimental substances.

Some of the air pollutants, their sources, and effects:

Name of the pollutants	Sources	Health effects
Nitrogen oxides	Industries, vehicles and power plants	Problems in the lungs, respiratory systems and causes asthma and bronchitis.
Carbon monoxide	Emission and burning of fossil fuels	Severe headache, irritation to mucous membrane, unconsciousness and death.
Carbon dioxide	Burning of fossil fuels	Vision problem, severe headache and heart strain.
Suspended particulate matter	Vehicular emission and burning of fossil fuels.	Lung irritation reduces development of RBC and pulmonary malfunctioning.
Sulphur oxide	Industries and power plant	Irritation in eyes and throat, allergies, cough etc.
Smog	Industries and vehicular pollution	Respiratory and eye problems
Hydrocarbons	Burning of fossil fuels	Kidney problems, irritation in eyes, nose and throat, asthma, hypertension and carcinogenic effects on lungs.
Chlorofluorocarbons	Refrigerators, emission from jets	Depletion of ozone layer, global warming

•  Other pollutants are cadmium, lead, mercury, silica, coal dust and particles and radioactive pollutants.

Control measures:

• Policy measures
• Modification of industrial process and selection of suitable fuels and its utilization.
• Collection of pollutants and convert it into less toxic forms by different methods.

Government initiatives:

• National air quality monitoring programme (NAMP)
• National ambient air quality standards (NAAQS)

WATER POLLUTION

• Addition of certain substances such as organic, inorganic, biological and radiological to the water, which degrades the water quality and makes it unhealthy for use.
• Water pollution is not only confined to surface water but also spread to groundwater, sea, and ocean.

Sources

Point sources: These are directly pointed towards the water bodies from the source of origin of pollution and are thus easy to regulate.

Non-point sources: These sources are related to many diffuse sources and are thus difficult to regulate.

Some of the sources are:

• Industrial and community wastewater: Industries like mining, iron and steel, pharmaceuticals, food processing, soap and detergent and paper and pulp.
• Agricultural sources, thermal pollution (discharge of hot water by thermal power plants cause deficiency of dissolved oxygen in water) and underground water pollution.
• Marine pollution: river discharge, manmade pollution and oil spills etc.

Effects

• An excessive amount of mercury in water can cause Minamata disease in humans and dropsy in fishes; Lead in large amount can cause dyslexia, Cadmium poisoning causes Itai – Itai disease, etc.
• Polluted water has less amount of Dissolved oxygen (DO) content which is important for sensitive organisms, thereby eliminates sensitive organisms.
• Excess of nitrate in drinking water is dangerous for infants and human health, excess fluoride cause neuromuscular disorder and teeth deformity, hardening of bones and painful joints.
• Biological magnification and eutrophication.

Note: ‘Eu’ means healthy and ‘trophy’ means nutrition. The improvement of nutrients in water bodies causes eutrophication. Domestic waste discharge, agricultural waste, land drainage and industrial waste in a water body leads to a rapid increase in nutrients in a water body which initiates early ageing of water bodies.

Control measures

• Usage of water should be minimized by changing the techniques involved.
• Recycling and treatment of water should be used to the maximum extent possible.
• The quantity of discharge of wastewater can be minimized.
• Excessive use of pesticides and fertilizers should be avoided.
• Organic farming and efficient use of animal residues as fertilizers.

SOIL POLLUTION

• Addition of unwanted substances to the soil which negatively affects physical, chemical and biological properties of soil and reduces its productivity is called soil pollution.
• The factors which disturb the biological balance of the soil and deteriorate the quality, texture, and mineral content are called soil pollutants.
• Use of fertilizers, pesticides, insecticides, dumping of solid waste, deforestation, and pollution due to urbanization and other anthropogenic substances causes soil pollution.

Sources

• Industrial waste: lead, cadmium, mercury, alkalies, organic substances, and chemicals.
• Agricultural waste: fertilizers, pesticides, insecticides, and manures.
• Discarded materials and radioactive elements and plastic bags.

Effects

• Agriculture: It reduces soil fertility and thus crop yields; increase soil erosion and salinity.
• Ecological imbalance and imbalance in flora and fauna further increases.
• Problems in urban areas like clogging in drains, the release of gases, foul smells, and problems in wastewater management.
• Release of radioactive rays, biomagnification and pollutant gases cause health problems.

Control measures

• Afforestation, reforestation and use of organic farming.
• Solid waste management and reduction of waste from the construction area.
• Stop the use of plastic bags and use bags of degradable materials like paper and cloth.
• Biomedical waste should be collected and incinerated in incinerators.

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.