Where is the worlds noisiest city?

The ignored pollutant can cause depression, stress, diabetes and heart attacks. What are cities doing to curb excess noise?

The constant roar of traffic, incessant construction noise, piercing sirens, honking horns, shrieking loudspeakers noise in cities is clearly a nuisance.

But its also a danger. The World Health Organisation (WHO) has described noise pollution as an underestimated threat that can cause hearing loss, cardiovascular problems, cognitive impairment, stress and depression. Some experts go further: they believe exposure to environmental noise could be slowly killing us.

Noise pollution causes hypertension, diabetes, obesity, heart attacks, strokes and death, says Dr Daniel Fink, chairman of the Quiet Coalition, a community of health and legal professionals concerned with the adverse impacts of environmental noise.

Noise pollution is often cited as one of the main factors in the reduced quality of life in large, 24-hour cities like New York (where more than 200,000 noise complaints were recorded in 2016). It causes stress, which has its own adverse effects on health.

While the impact of noise on mental health has not been studied extensively, research has shown that strong noise annoyance is associated with a twofold higher prevalence of depression and anxiety in the general population.

A recent study by experts at the American College of Cardiology linked noise pollution to increased cardiovascular problems (high blood pressure, heart attacks, stroke, coronary heart disease) through the bodys stress mediated response resulting in the release of the stress hormone cortisol, which in turn damages blood vessels.

At a conference on noise organised by the European commission in April 2017, noise was regarded as the silent killer, with potentially severe consequences for our physical and mental health. And yet its impacts remain unreported and underestimated.

Worst offenders

Dr Eoin King, assistant professor of acoustics and author of the book Environmental Noise Pollution, calls noise the ignored pollutant. Environmental noise still continues to be poorly understood by practitioners, policymakers and the general public, he says.

Most worrying, says King, is the impact on children. Studies considering the effect that noise may have on children have found that tasks such as reading, attention span, problem-solving and memory appear to be most affected by exposure to noise.

The issue is compounded by debate over how much noise it is safe to be exposed to. In its Make Listening Safe guide, WHO states that 85 decibels is considered the highest safe exposure level, up to a maximum of eight hours. However, others Fink among them argue this is still too loud.

A car measures 70 decibels, a jackhammer 100, and a plane taking off 120, according to the WHO. Though there is no set threshold to establish risk, we do know that anything above 60 decibels can increase risk for heart disease, Dr Thomas Mnzel, from the Mainz University Medical Centre, has said.

A recent report by the BBC found that parts of the London Underground were loud enough to damage peoples hearing, with noise levels greater than 105 decibels on many lines. The report stated that some were so loud they would require hearing protection if they were workplaces.

Guangzhou
Guangzhou has been ranked as having the worse levels of noise pollution in the world Photograph: ChinaFotoPress via Getty Images

Concerned about increased risk of hearing loss in cities, last year Mimi Hearing Technologies created a World Hearing Index to draw attention to the issue. With the results of hearing tests of 200,000 of their users worldwide and data on noise pollution from WHO and Sintef, a Norwegian research organisation, the index plotted levels of noise pollution and hearing loss in 50 cities.

The study found that, on average, a person living in the loudest cities has hearing loss equivalent to that of someone 10-20 years older. Overall the results showed a 64% correlation between hearing loss and noise pollution.

Guangzhou, China, ranked as having the worse levels of noise pollution in the world, followed by Cairo, Paris, Beijing and Delhi. Of the 50 cities, Zurich was found to have the least noise pollution.

Participants in Delhi recorded the highest average hearing loss equivalent to someone 19.34 years older than them. Vienna had the lowest hearing loss but still, on average, that of someone 10.59 years older.

We were able to collect quite a unique hearing data warehouse on hearing abilities across countries and continents, says Henrik Matthies, managing director of Mimi Hearing Technologies. There is an obvious known correlation between being exposed to noise and decreased hearing ability.

However, mapping this correlation to cities helped us to get the message out, sparking a debate about noise pollution and hearing in megacities like Hong Kong and Delhi.

But what can be done about it?

Political will

The EU are probably the world leaders at setting out a process to tackle noise pollution, says King. In 2002, it issued an environmental noise directive that requires member states to map noise exposure in urban areas holding upwards of 100,000 people, to develop noise abatement action plans in these areas and to preserve quiet areas.

Action plans usually incorporate a variety of measures such as traffic management strategies, promoting light rail systems and electric buses, reduced speed limits, introducing noise barriers and improved planning processes.

But good intentions only go so far. The problem is that there is no real enforcement associated with these action plans, says King. Until there is more of a political will to drive planning decision related to noise, I dont think much will change.

With road traffic by far the largest source of noise pollution in Europe, affecting an estimated 100 million Europeans, concepts like Pariss car-free day could have an impact. For one day every month in the French capital, 30% of the city becomes off limits to vehicles. The project has seen sound levels in the city centre drop by half.

The most effective way to control noise is at the source. If we could make planes, trains and cars quieter we would solve a lot of our problems, says King. If all vehicles in a city street were electric, noise would be significantly reduced.

Increasingly citizens can also do their bit to monitor noise pollution in cities by transforming their smartphones into sound level meters.

The NoiseTube app, developed by researchers at the Free University of Brussels in Belgium, enables users to record where and at what times decibel levels are highest to produce a detailed noise map of the city. Councils can use the data to target noise pollution more effectively, using sound absorbent materials such as foam and fibreglass precisely where they are needed most.

King says there are many such projects looking to harness the potential of big data in the fight against noise for example, noise complaint data, or social media chatter related to noise, to better assess public sentiments towards soundscapes. There is a lot going on which I suppose gives us some hope.

Follow Guardian Cities on Twitter, Facebook and Instagram to join the discussion, and explore our archive here

Read more: https://www.theguardian.com/cities/2018/mar/08/where-world-noisiest-city

How do you build a healthy city? Copenhagen reveals its secrets

The Danish capital ranks high on the list of the worlds healthiest and happiest cities. With obesity and depression on the rise worldwide, here are its lessons for how to combat them culturally

How do you build a healthy city? Copenhagen reveals its secrets

How do you build a healthy city? Copenhagen reveals its secrets

The Danish capital ranks high on the list of the worlds healthiest and happiest cities. With obesity and depression on the rise worldwide, here are its lessons for how to combat them culturally

Read more: https://www.theguardian.com/environment/2018/feb/11/how-build-healthy-city-copenhagen-reveals-its-secrets-happiness

Why November Means Unsafe Air in India’s Capital: QuickTake Q&A

For the third straight November, thick toxic smog has enveloped India’s capital, New Delhi, forcing schools to shut down, halting traffic and sending residents scurrying to buy air purifiers and filtration masks. United Airlines briefly suspended service to the city, the Indian Medical Association declared a public health emergency, and India’s Supreme Court slapped a ban on selling fireworks ahead of Diwali, the Hindu festival of lights. Chief Minister Arvind Kejriwal, the leader of the metropolis that’s home to 20 million people, has called New Delhi a "gas chamber." It’s not even India’s worst city for pollution.

1. What causes the smog?

Mostly it’s the burning of crop stubble, which continues unabated despite being banned in the surrounding states of Punjab, Uttar Pradesh, Haryana and Rajasthan. Farmers in those regions traditionally clear their fields by burning in preparation for the winter season. Contributing to the pollution are vehicle and industrial emissions, road and construction dust, and fires lit by the poor for domestic use. Compounding the problem: The trough-like topography of the north Indian region means polluted air lingers in colder months.

2. What is the point of stubble burning?

After rice, wheat or other grain is harvested, the straw that remains is called stubble, and it must be removed before the next planting. It once was used as cattle feed, or to make cardboard, but harvesting by combine (rather than by hand) leaves 80 percent of the residue in the field as loose straw that ends up being burnt. Disposal of the stubble by means other than burning — such as plowing it into a fine layer of field cover — costs time and money, two things that farmers say they can’t afford.

3. How serious is the health risk?

The World Health Organization warns that increasing air pollution in many of the world’s poorest cities is driving up the risk of stroke, heart disease and lung cancer in vulnerable populations. The World Bank estimated that 1.4 million people in India died prematurely due to air pollution in 2013, the latest year for which data is available. (Pollution has worsened since then.) The most dire threat to humans is from PM 2.5, the fine, inhalable particles that lodge deep in the lungs, where they can enter the bloodstream. World Health Organization guidelines say exposure to PM 2.5 above 300 micrograms per cubic meter is hazardous. New Delhi’s recent readings have exceeded 1,000, as they did last year.

4. Why not enforce the ban on burning?

Farmers are a strong electoral constituency. Getting them to change their ways is no easy task, particularly as labor shortages bite and push up the costs of removing stubble manually.

5. Does the problem end when the burning stops?

The worst of the pollution typically dissipates as spring begins, but New Delhi’s air remains dirty all year. On every day in 2017, PM 2.5 readings exceeded the level deemed healthy by the WHO (up to 50 micrograms per cubic meter). And there were 39 days when readings topped 300, according to U.S. embassy data through Nov. 20.

6. Then what action is India taking?

New Delhi takes temporary measures, such as restricting traffic on alternate days or attempting to prevent the burning of waste. The federal government has accelerated the timeline for stricter emission rules; oil refiners plan a 288 billion-rupee ($4.4-billion) outlay on upgrades to comply with a local equivalent of European emission standards by April 2018.

7. Why hasn’t more been done?

The chaotic nature of Indian democracy doesn’t lend itself to coordinated action. Unlike in China, where the one-party government has directed a concerted nationwide anti-pollution drive, India’s various levels of government have failed to make meaningful progress on an issue that sprawls across political jurisdictions run by rival parties. At the same time, pollution hasn’t become as important an issue at the ballot box as, say, inflation or employment.

8. Where else in India is pollution a serious problem?

India accounted for 19 of the 35 worst-polluted cities in the world, as measured by PM 2.5, in WHO’s 2016 rankings. The Indian cities of Gwalior and Allahabad ranked second and third, behind only the Iranian city of Zabol, which is beset by dust storms. New Delhi, ranked 11th, was behind Saudi Arabia’s Riyadh for most polluted capital city.

9. What’s the impact on the economy?

The World Bank in 2013 estimated the annual cost of environmental degradation in India at $80 billion. According to a study by the Lancet Commission on Pollution and Health, pollution-related illnesses drag down productivity and reduce annual economic output by as much as 2 percent in developing economies.

10. What can India do?

To start, it could implement measures it’s already approved. That means enforcing the ban on burning crop stubble, holding to stricter emissions targets for 2020 and forcing construction sites to stick to rules on creating dust. Phasing out diesel cars and adopting cleaner fuels like compressed natural gas would also help, as would strengthening the public transport system to reduce the number of vehicles on the road.

The Reference Shelf

    Read more: https://www.bloomberg.com/news/articles/2017-11-23/why-november-means-unsafe-air-in-india-s-capital-quicktake-q-a