Tackling Noise Pollution in Cities: Why and How

Noise pollution is the second most important environmental health risk in Western Europe, only after air pollution. It affects our sleep, our mood, our productivity, and our health.

According to the European Environment Agency (EEA), in most European countries, more than 50% of people living in urban areas are exposed to harmful levels of road traffic noise, while one in five Europeans is regularly exposed to noise levels at night that could significantly affect their health. Society pays a high price for this: the latest estimates show that at least 1 million healthy years of life are lost each year in Western Europe due to traffic-related environmental noise. However, the impact of noise on health is often underestimated and awareness of this public health problem is still low.

Noise and health: what do we know so far?

Noise can affect health in many ways, including auditory and non-auditory effects. Auditory effects, such as hearing loss and tinnitus, occur when we are exposed to high levels of noise. In contrast, non-auditory effects can occur at relatively low but constant levels of environmental noise, even when we think we have adapted to it. This is because our bodies react to the daily and constant exposure to noise (for example, by triggering hormonal responses), even if we are not consciously aware of it. 

Non-auditory effects include suffering from chronic annoyance and sleep disturbance, cognitive impairment, and cardiovascular and metabolic disorders. However, there are other non-auditory health effects of noise that are currently being investigated and require further research. These include mental health problems (such as depression and anxiety), metabolic disorders (such as obesity and diabetes), and adverse birth outcomes (such as increased risk of preterm birth and low birth weight). There is growing evidence that exposure to aircraft and road traffic noise at school may affect children’s cognitive development. It has also been suggested that noise stress may aggravate respiratory diseases, or that exposure to traffic noise may be involved in the development of some types of breast cancer.

Sleep disturbance, long-term noise annoyance and heart disease are the three health outcomes with the strongest evidence to date

In addition to these health effects, we should also consider the potential indirect effects of living in noisy areas. For example, traffic noise may lead to physical inactivity through sleep disturbance or reluctance to walk in noisy environments, while some studies have reported associations between traffic noise and lifestyle factors such as smoking, alcohol consumption or medication use. So, the full range of ways in which noise affects our health and well-being is still being explored, and the effects may be greater than we currently estimate. But for now, sleep disturbance, long-term noise annoyance and heart disease are the three health outcomes with the strongest evidence to date, according to the WHO’s latest guidance document, Environmental noise guidelines for the European Region.

Figure: Summary of the links between noise and health. Based on WHO (2018) and EEA (2020)

How much noise is too much?

Having established that noise can affect health in a number of ways, how do we know what levels of noise are harmful to our health? The WHO defines exposure thresholds at which (according to the latest evidence) adverse health effects start to build up. These thresholds vary depending on the source of the noise, and whether we are exposed to it during the day or at night. For example, we are less tolerant of aircraft noise at night than of road traffic noise.

The current EU Environmental Noise Directive (END) does not set limit values, but rather reporting thresholds. To comply with the END, strategic noise maps should show those areas where day–evening–night noise level (Lden) is above 55 dB and night-time noise level (Lnight) is above 50 dB. This means that there is currently a lack of data on the number of people exposed below 55 dB Lden and 50 dB Lnight, as reporting of these levels by countries is voluntary. What’s more, the current EU thresholds are too high and should be updated in line with the latest WHO guidelines, as health effects occur at levels below these thresholds, and are therefore likely to underestimate the health impacts of noise. Converting these thresholds into binding limits should be considered, as for air pollution.

The health effects of noise can also vary between population groups. Populations considered to be particularly vulnerable to noise include: children, the elderly, shift workers, pregnant women, ‘noise sensitive’ people, people with pre-existing health conditions. However, as is often the case with exposure to health risks, the most disadvantaged are likely to suffer disproportionately. Households with lower incomes often cannot afford to live in quiet residential areas or have insulated homes. They may also be at higher risk of suffering pre-existing health conditions and have fewer options for coping with noise. Night-time noise that affects sleep can lead to increased visits to the doctor and spending on sleeping pills, which affects families’ budgets. The gap between rich and poor is therefore likely to widen if we do not tackle noise pollution; especially in urban areas. This makes noise not only a health issue, but also an equity issue.

What can be done about it?

There are many different noise abatement measures in use in European cities today, ranging from low-noise asphalt and tyres, to innovative noise barriers (e.g. made from recycled rubber tyres or upcycled wind turbines) or environmentally friendly noise shelters. Paris, one of the noisiest European cities (according to the ISGlobal Ranking Of Cities) is using the latest technology in ‘noise radars’ to identify and fine the noisiest vehicles.

But the most effective way to tackle noise pollution is through urban management and design strategies that change what we do, and how we move around the city (e.g. redesigning streets to give more space to cyclists and pedestrians, or creating low noise zones). In particular, those measures that can significantly reduce motorised traffic, although still being unpopular in many countries, can be win-win solutions in terms of noise pollution, air pollution, walkability, and creating a healthier environment overall. In fact, 50% of all car journeys in European cities are less than 5 kilometres; a distance that can easily be covered by less polluting means of transport. Every trip we don’t take by car has a positive effect in terms of less noise and less air pollution. And probably more physical activity. All of which means a better urban environment and better health.

Every trip we don’t take by car has a positive effect in terms of less noise and less air pollution. And probably more physical activity. All of which means a better urban environment and better health

ISGlobal Urban Planning, Environment and Health Initiative has designed a free online course with the EIT Urban Mobility Academy, entitled Tackling noise pollution in cities. With the participation of Maria Foraster, Mark Nieuwenhuijsen and Carlota Sáenz de Tejada from ISGlobal, the aim of this course is for people to learn more about such a major environmental health risk and the best strategies to reduce noise in cities. We encourage anyone interested in the topic to enroll and become part of the silent change!