Report:Wholesome Air, Serene Cities – reduced noise and air pollution in urban areas
“Air pollution” refers primarily to airborne components that have negative effects on human health, such as respiratory issues, cancer, stress, sleep disturbance and premature death. Many pollutants can also damage plants, trees and crops and cause deterioration to buildings and landmarks of historical and cultural value.
A city’s sounds can turn into harmful noise if the sound level becomes too high and remains high without periods of lower noise levels, and if the sounds are perceived by residents as unnecessary and disturbing. Noise is not only annoying for those affected by it – it can also lead to stress, sleep disturbance, hypertension and even premature death.
Air and noise pollution often originate from the same sources, such as traffic, machinery used on construction sites, and local point sources such as power plants and generators.
Noise and air pollution in European cities
European cities have varying concentrations of air pollutants. While densely populated cities with heavy traffic are generally more polluted, local meteorology and topography (e.g. cities located in geological basins/valleys) have a major effect on pollution levels.
Approximately 75 million citizens living in European urban areas are exposed to noise levels above Lden 55 dB, which is the threshold level recommended by WHO. Road traffic noise is the foremost source of noise exposure. Based on available noise mapping data reported by European countries for 2012, an estimated 11 million urban residents are annoyed by road noise and 5 million suffer from sleep disturbance. It is similarly estimated that reported road noise exposure causes 500,000 cases of hypertension, 43,000 cases of heart disease and 10,000 premature deaths every year. In Europe air pollution is responsible for about 500.000 premature death each year.
European countries have taken several different initiatives to reduce urban noise and air pollution. Noise maps and noise action plans have been produced for the largest cities, but these initiatives have not yet reduced the number of citizens affected by urban noise. The EU has adopted several directives in order to control and improve air quality. The primary directive is the Ambient Air Quality Directive, which requires member states to monitor and control air quality in cities and rural districts. The directive sets limits for maximum pollution levels for certain air pollutants.
Although air quality in Europe has improved over the past 20 years, the rate of reduction of harmful substances in the air has decreased in recent years. Further urbanisation and climate change may even cause increased pollution and harmful noise in years ahead.
Reducing noise and air pollution
Solving noise and air pollution problems requires a long-term strategy for transportation systems, production and construction methods, in favour of quieter, more environmentally friendly solutions. Noise pollution can be mitigated at the source, during propagation and at the recipient (homes, schools, etc.). Air pollution can only be mitigated at the source and, to a very minor degree, at the recipient. It is important to identify solutions to pollution both in existing urban areas and when planning new urban areas.
Noise and air pollution can be reduced by removing or reducing traffic in sensitive areas. This may involve reducing or banning heavy vehicles inside the city centre, restricting the speed to 30 km/h for all vehicles, banning studded tyres and older diesel vehicles and, in the longer term, only allowing e-cars. Good conditions for cyclists and public transport will also help reduce polluting traffic. Another possible measure may be to require delivery of goods to shops by smaller vehicles.
Technological solutions to reduce air and noise pollution are available, although efficiency can be improved through further development and combination of solutions. Noise screens and low-noise asphalt are two technological solutions that are used in many cities. Intelligent traffic regulation, aimed at decreasing stop-and-go driving, and improved fuel efficency for cars are examples of technological meausers that can reduce air pollution. Electric buses are already reducing noise and air pollution in some European cities and are likely to become even more common in the future.
Calm areas – areas undisturbed by environmental noise – can provide significant health benefits to citizens. Such areas can be found in city parks, between blocks of flats, in courtyards, gardens and leisure areas. When developing existing urban areas and designing new ones, it is important to include designated and protected calm areas. Methods of creating calm areas in the city include designating low speed limit zones, restricting heavy vehicles and encouraging bicycle use and road sharing. The effects of a calm area can be enhanced using noise screens and noise-absorbing surfaces such as green areas and greenery.
Noise insulation and dwelling ventilation
In existing urban areas with canyon-like streets and heavy traffic, the best solution may be to reduce noise and air pollution inside people’s homes. With mechanical ventilation, air filters and noise insulation for windows, walls and ceilings, harmful noise and air pollution can be significantly reduced.
Today, residents of European cities have to accept that health hazards associated with noise and air pollution are just a necessary evil that comes with the benefits of living in an urban area. But it doesn’t have to be this way. Through the work of urban planners and other stakeholders the negative effects of noise and air pollution can be substantially reduced – improving quality of life for millions of Europeans.
Wholesome Air, Serene Cities – reduced noise and air pollution in urban areas
About the authors
Kenneth Lillelund is a noise expert specialised in environmental noise and noise mitigation measures. He has more than 20 years of experience in noise assessment of infrastructure and urban development projects. He is committed to working with customers, public authorities and other technical disciplines to identify good solutions. Kenneth has contributed to guidelines for implementation of the European Noise Directive in Denmark and Romania.
Knud Erik Poulsen has over 25 years’ experience as a consultant specialised in Danish and European environmental regulation of air pollution from industrial activities and traffic. He has extensive experience in air pollution dispersion modelling and the assessment of industry and traffic-related air pollution in relation to environmental impact assessments for projects and plans. Knud Erik has worked on air pollution projects in more than 15 countries.
Christina Halck is an expert in air pollution calculations and has extensive experience as a consultant on air pollution from industrial activities and traffic. She has many years’ experience as a consultant specialised in Danish and European environmental regulations and has contributed to many environmental impact assessments for infrastructure projects and industrial customers.
Other contributing experts from Sweco
Johanna Thorén, Emma Hedberg and Leonard Kolman