Pollution is the next stop on Paul Reeve's journey through the IEMA Associate certificate syllabus
The term “pollution” encompasses environmentally harmful outputs from a remarkably complex range of activities, products and services. Activities, products and services generally require “inputs” – for example, materials and energy. They also generate “outputs”, such as useful products and recovered materials. Releases to the environment are also outputs. These include atmospheric emissions, effluent discharges, solid wastes, or the release of engineered materials, noise, vibration, heat or light.
The sources of these releases may be “point” sources, such as a discharge pipe to natural waters, or the combustion stack of an industrial process. Or they might be “diffuse” sources, including individual traffic emissions, which raise aggregate airborne concentrations and noise to unwanted levels, or the widespread application of various chemicals to land, causing contaminated runoff to surface waters.
Aspects and impacts
ISO 14001, the leading international standard for environment management systems, carries a very useful definition of how organisational activities can interact with the environment (see below). Pollution from an activity, product or service – referred in the 14001 terminology as an “aspect” – is a release to the environment that may have negative environmental impacts. Polluting outputs and associated environmental impacts include the following.
- Climate change – greenhouse-gas emissions, including the six covered by the Kyoto Protocol: carbon dioxide, methane, sulphur hexafluoride, nitrous oxide, perfluorocarbons, hydrofluorocarbons.
- Tropospheric ozone creation (low-level photochemical “smog”) – emissions of nitrogen oxides, carbon monoxide and volatile organic compounds/unburnt hydrocarbons.
- Acid deposition – emissions of sulphur dioxide, nitrogen oxides and hydrogen fluoride/chloride.
- Other air-quality impacts (notably leading to serious/persistent health problems) – particulates (including smoke and dusts), nitrogen oxides, sulphur dioxide, benzene, lead and dioxins (waste product of manufacture/burning of chlorinated organics/plastics).
- Water pollution – discharges of suspended solids, nitrates and phosphates, oil, solvents, heavy metals, endocrine disruptors (hormonal effects), persistent organic substances, pesticides, other organic matter, thermal (heating) and litter.
- Contaminated land (often linked to both ground and water pollution) – accumulations of hazardous substances and wastes, such as heavy metals (for example, cadmium and lead), asbestos, organochlorine compounds, combustible and explosive materials and biological contamination.
- Waste – generation of contained solid and liquid wastes, hazardous wastes and radioactive wastes.
- Nuisance – smoke, dust and fumes, accumulated waste/litter, and intrusive odour, noise/vibration and light.
In addition, there is pollution of the stratosphere from manmade molecules, which could cause ozone depletion (see below). Pollution can range from steady/intermittent and long term, to major and immediate incidents. The polluting outputs from major incidents (including substances used to deal with the incident) can include: oil spills (including dispersants); chemical spills/spreading; explosions and fires (including firewater); and radioactive incidents. However, long-term sources of pollution – notably noise pollution – can interfere with the quality of life and, if exposure is excessive, can harm health.
Nature’s capacity to fight back
Nature’s ability to reduce the negative impacts of pollution depends on several key factors such as the type of pollution; how much is generated, and over what duration; the receiving environmental medium (air, water or land); and receptors (the type, and how sensitive they are to a given pollutant).
However, not all of nature’s processes reduce environmental impacts. There are many examples of environmentally “persistent” substances that have significant lifetimes. These range from toxic organochlorides (that build up in the human food chain), carbon dioxide (now infamously associated with climate change), CFCs or chlorofluorocarbons (a major culprit behind stratospheric ozone depletion – a single CFC molecule, for example, can destroy 100,000 ozone molecules), asbestos (persistent and toxic) and various radioactive wastes.
Furthermore, some natural processes may increase negative impacts. For example, urban airborne emissions can be broken down by sunlight, leading to the formation of substances harmful to health (such as ground-level ozone). In addition, some pollutants have more than one environmentally harmful characteristic.
Methane, another example, is a potent greenhouse gas – linked to climate change. It is the principal component of natural gas, so is also potentially flammable and explosive. Methane is also formed and released to the atmosphere by biological processes occurring in anaerobic environments. Once in the atmosphere, methane absorbs terrestrial infrared radiation that would otherwise escape to space. This property can contribute to the warming of the atmosphere, which is why methane is a greenhouse gas. It is about 21 times more powerful at warming the atmosphere than an equal weight of carbon dioxide.
Environmental receptors
Once released to the environment, pollution follows natural pathways – wind, rain, flowing water, permeable ground, the food chain (see diagram below). It then has a negative impact on one or more parts of the environment, which are known as receptors. These impacts can occur over the short or longer term, depending on the nature and extent of the pollutant and the sensitivity of the receptor. The following provides examples of pollution sources, pathways and receptors:
- Polluting sources – combustion emissions, dust, effluent discharges, leaks and spills, dumped or poorly managed waste.
- Environmental pathways – atmosphere, water (rivers, lakes, aquifers, coasts, seas), and land (including surface and underground contamination, and groundwater).
- Receptors – humans, neighbours, wider population, sensitive individuals/communities (“at risk” receptors); natural and owned resources, including crops and livestock, wildlife (plants and animals), conservation/sensitive species and habitats (“at risk” receptors), and buildings and structures.
Pollution can cause significant harm to biological receptors and can include exposing humans to toxic, carcinogenic, endocrine-disrupting or bioaccumulative substances, heating natural waters and degrading the surrounding environment. It can ultimately affect the quality of ecosystems and biodiversity.
Finally, there is not always a clear distinction between environmental receptors and pathways. For example, water and land can be both pathways and receptors, as can organisms in a food chain.
Compelling case
The factors above are persuasive reasons for organisations to prioritise pollution prevention and minimisation, rather than attempting to clean pollution up once it has happened.
But another crucial factor is that, if a substance is released into the environment, it may be impossible to predict what will happen next, much less control the environmental impacts. Once pollution occurs, the time for cost-effective control has gone.
Depending on the scale and location of the pollution, clean-up costs can be huge. BP, for example, set aside $41 billion to cover costs related to the Gulf of Mexico spill. More than four million barrels of oil poured into the sea when an explosion ripped through the Deepwater Horizon drilling rig in April 2010, spreading pollution over 600 miles and damaging marine life and coastal wetlands between Louisiana and Florida.
This is why the international environment management system standard 14001 says that environment managers should seek to control “aspects”, not “impacts”. The “prevention of pollution” is so fundamental that 14001 specifically requires organisations to commit, in their environment policy statement, to achieving it.
Useful definitions
The following definitions are from ISO 14001, the international standard for environment management systems:
- Environmental aspect – “Element of an organisation’s activities, products or services which can interact with the environment (a‘cause’ of impacts).”
- Environmental impact – “Any change to the environment, whether adverse or benefi cial, wholly or partially resulting from an organisation’s environmental aspects.”
The 2008 EU Directive on integrated pollution prevention and control (2008/1/EC), which replaced the earlier Directive (96/61/EC), defines pollution as: “The direct or indirect introduction, as a result of human activity, of substances, vibrations, heat or noise into the air, water or land which may be harmful to human health or the quality of the environment, result in damage to material property, or impair or interfere with amenities and other legitimate uses of the environment.”
Many consider the reference to “quality of the environment” to include biodiversity (species and ecosystems, including the food chain). Note that “activity” can include storage. Example “services” range from delivered goods to the provision of information and communication technology (providing services still require substances and energy to be released into the environment throughout the supply chain).
Ozone depletion
Some man-made molecules which incorporate chlorine and bromine atoms do not break down readily in the lower atmosphere (troposphere). These molecules, more widely known as “halogenated” molecules, can persist for decades if they are released into the environment (as gas or vapour) and can eventually reach the upper atmosphere (stratosphere). Here, solar ultraviolet radiation breaks up these molecules, creating free chlorine and bromine atoms. These atoms cause further complex reactions, including the conversion of stratospheric ozone molecules to oxygen. This is “ozone depletion”, and its impacts are most acute at high latitudes. It is a major environmental concern because the ozone layer protects the Earth’s surface from excessive solar ultraviolet radiation. When the ozone layer thins, extra UV radiation reaches the surface, increasing the risk of harm to humans, animals, crops and other plants.
This serious and widespread negative impact was not originally anticipated. But by the 1980s, scientists had not only identified the phenomenon of polar ozone depletion but had also established the convoluted link to halogenated gases. During the next decade, the main response of global governments was to progressively ban the production and use of a range of halogenated ozone-depleting substances, including chlorofluorocarbons and halons.
It is widely believed, although it will take years to confirm conclusively, that the bans have started to help the ozone layer to recover.
The polluter pays principle
The polluter pays principle (PPP) recognises that the polluter should pay for any environmental damage it causes, and that the burden of proof in demonstrating that a particular technology, activity or product is “safe” to health, the environment or both should not lie with the public or its representatives.
The PPP is mentioned in principle 16 of the Rio Declaration on Environment and Development. This says that nations should: “Endeavour to promote the internalisation of environmental costs and the use of economic instruments, taking into account the approach that the polluter should, in principle, bear the cost of pollution, with due regard to the public interest.”
The PPP has been adopted by the European Commission, which says the principle implies that those who cause “environmental damage should bear the costs of avoiding it or compensating for it. Therefore public financing of environmental policy … should be financed by the polluters themselves as far as they can be identified.”
In the UK, the PPP is one of the five “guiding principles” behind the government’s current sustainable development policy. The “Achieving a sustainable economy” principle includes the following: “Building a strong, stable and sustainable economy which provides prosperity and opportunities for all, and in which environmental and social costs fall on those who impose them (the ‘polluter pays’) and efficient resource use is incentivised.”
In environmental law, the PPP is applied, for example, when seeking compensation from those whose activities have harmed the environment. However, it is also cited when authorities recover the cost of issuing permits for activities that have the potential to cause pollution, even where there has been no civil or criminal offence.
IEMA Associate certificate – sources, effects and management of releases
- Principal sources of pollutants
- Main pathways of pollutants and their behaviour
- How pollutants adversely affect air, land, water and, consequently, people
- How pollutants impact on habitats and species
- Origins of key environmental issues and their implications, such as climate change, ozone depletion and bio-accumulation
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Prevention and control of releases including key biological, physical and chemical technologies
