Keyword air pollution; water pollution; noise nuisance; sustainable transport

The environmental effects of transport are diverse and wide-ranging, and can extend to air, water and land. Air pollution from transport can be very localized or have transboundary and global effects. In dense traffic zones, pollution emissions are emitted close to the place where the impacts appear whereas other pollutants can travel long distances before they are deposited on the ground. The emission of greenhouse gases (CO₂), of which transport is one of the main sources, has global impacts, which have been shown to lead to global climate change. For instance, in the EU, while passenger cars have became more efficient, the growth in transport demand has increased, resulting in a increase in emissions of greenhouse gases from transport by 20% over the past decade. (TERM Indicators 2004).

Ground-level ozone is a key component of summer smog, and is formed from a mixture of nitrogen oxide and volatile organic compounds, which originates primarily from transport, especially in urban areas. Ozone negatively affects health and also causes harm to ecosystems. Acidification is caused by emissions of nitrogen oxides and sulphur emissions. This affects fish populations and forest soils, especially in sensitive areas in Europe. Eutrophication also stems from nitrogen oxide emissions, and causes some plant species to grow excessively and others to disappear, thereby reducing biodiversity. Both acidification and eutrophication are hazardous to human health as well as the environment.

In addition, air pollution has been shown to lead to increased mortality and morbidity. In a study carried out in Austria, France and Switzerland as part of the preparation of the London Conference on Environment and Health (1999), which provided an estimate of the health effects of air pollutants from traffic and their related costs, it was found that in the three countries air pollution has been estimated to cause 6% of total mortality, or more than 40,000 attributable cases per year. In countries where leaded petrol is still used, children exposed to lead from fuel are at a higher risk of suffering negative impacts on neuro-cognitive functions.

Transport also has effects on water pollution, both directly and indirectly. Examples of transport-related activities leading to water pollution include the use of de-icers on roads and airports, contamination of rainwater gutters by fuel or motor oil and maritime fuel tank flushing.

Transportation, and in particular road transport, is a primary source of noise pollution in Europe. It has become a growing concern for an increasing segment of the population in recent years, especially in urban areas. Road traffic is the predominant source of human exposure to noise, except for people living near airports and railway lines. The health effects of noise include stress, reduced psychological well-being, and sleep disturbance. Children are particularly vulnerable to the effects of noise, for instance with respect to impairments of their reading acquisition, and attention and problem-solving abilities.