Impacts of Air Pollution

​​Air pollution can be defined as presence in the atmosphere of one or more contaminants which may be harmful to the environment, causing impacts on human health, crops, forests, fisheries, semi-natural ecosystems and materials (e.g. corrosion) etc.Air pollution from sulphur and nitrogen emissions can give rise to impacts close to sources in urban areas or in the vicinity of major industries. Pollutants can also cause impacts far from the source, through transfer in the atmosphere by winds, and may also cause impacts across national boundaries. Impacts of air pollution may therefore be both localised and/or transboundary in nature. Pollutants are emitted as gases, such as sulphur dioxide and nitrogen dioxide, and these can have direct impacts on the environment. Furthermore, the nitrogen oxides may react with volatile organic compounds to give rise to ozone gas, which is also damaging to health and vegetation. During transport in the atmosphere the sulphur dioxide is transformed into sulphuric acid and nitrogen oxides into nitric acid, which give rise to acidic deposition, causing potential acidifying effects on ecosystems.

There are a number of ‘regional’ air pollutants including sulphur oxides, nitrogen oxides, ammonia, tropospheric ozone, heavy metals and persistent organic pollutants (POPS). As it is used here ‘regional’ refers to that part of the issue that is not solely local (e.g. urban areas) or global (e.g. global climate change). In that emissions often give rise to local impacts and also regional effects after long-range transport, local impacts are considered part of the regional air pollution problem. Although there are a number of regional air pollutants, which are important in developing countries, the Malé Declaration on Control and Prevention of Air Pollution and its likely Transboundary Effects is concerned with impacts of sulphur and nitrogen compounds and tropospheric ozone.

regional Transport

Air Pollution in South Asia

In South Asia, air pollution as a local issue has been partially addressed by legislation in most countries. Further action has not been taken because the knowledge base concerning linkages between observed pollution levels and established health effects in South Asia is weak. As a result, there is some degree of complacency, which does nothing to discourage the development of polluting activities in the interest of promoting industrial and social development in South Asia. It is not inevitable that the promotion of economic development entails increased pollution. The “precautionary principle” has not come into play as yet in this field due to the imperatives of “growth” and lack of conclusive evidence to establish the existence of effects. By taking such concepts and impacts into account development paths may be chosen that both promote development and minimise the impact on the environment.

Malé Declaration

In view of the above, governments in South Asia have agreed that initiatives are required such that risks from air pollution may be understood and emissions prevented as required. The Malé Declaration was formulated and approved at the seventh meeting of the Governing Council of SACEP held on 22 April 1998 in Malé, Republic of Maldives. This followed a policy dialogue held at AIT, Bangkok, in March 1998 where a draft declaration was developed by the participants. The development of the policy process rests on a thorough understanding of the issues relating to air pollution.

Baseline Studies and Action Plans

The signatories to the Malé Declaration stated the need for countries to carry forward or initiate studies and programmes on regional air pollution in each country of South Asia. The first stage in this process is to document current knowledge and structures in each nation relevant to air pollution issues. To this end it has been agreed that baseline studies will be developed. There will be a number of gaps in the current status of knowledge and infrastructure which will become apparent from the information gathered by the baseline studies. These gaps will need to be filled to aid the policy process and, for this reason, action plans need to be developed in each country which, when implemented, will create a solid scientific basis for the policy process. There is a need for integration of national efforts and data on a sub-regional basis. The format for this will be discussed amongst SACEP, NIAs and Environmental Ministries, together with advice from UNEP/EAP-AP and SEI.

Accompanying this document are two further documents, the purpose of which is to assist the National Implementing Agencies (NIAs) in preparing the baseline studies and Malé Declaration action plans (national) to support the implementation of the Malé Declaration. The additional documents are designed to help in the production of the baseline report and Malé Declaration action plan (national) report. These are:

Part I: Guidelines for the Preparation of Baseline Studies (61.8 KB)

Part II: Guidelines for the Preparation of Malé Declaration Action Plans (National) (22.5 KB)

Note: The national reports should be produced both in hardcopy and digital format (in MS Word)

These guideline documents have been produced by Mylvakanam Iyngararasan and Surendra Shrestha of UNEP/EAP-AP (Environmental Assessment Programme for Asia and Pacific) and Johan Kuylenstierna and Kevin Hicks of SEI (Stockholm Environment Institute). These guideline documents have also been reviewed and adopted by the National Implementing Agencies. Sida, the Swedish International Cooperation Development Agency, has funded this part of the implementation of the Malé Declaration.

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Sri Lanka