Road traffic noise is the most pervasive and rigorous type of noise pollution. It has become a serious problem nowadays because of inadequate urban planning in the past. Schools, homes, offices, commercial business centers, hospitals, and community buildings were built close to the main roads without adequate soundproofing or buffer zones. The problem has also been aggravated by an increase in traffic volumes, such as heavy motor vehicles, two-wheelers, and other vehicles.
Evidence is also emerging associating road noise to health problems, such as sleep problems, headaches, tiredness, stress, hormonal effects, high blood pressure, and increased risk of heart disease. Now, a team of researchers from the University of Oxford has found a connection between traffic noise and obesity. They said that long-term exposure to road traffic noise, such as living near a busy road or motorway, was linked with increased waist circumference and body mass index. These two are key markers of obesity, reports Science Daily.
Transport noise exposure and obesity
Yutong Cai from the Nuffield Department of Women’s & Reproductive Health at the University of Oxford and colleagues wrote that the environmental stressors contribute to increased levels of stress hormones, disrupts the function of the endocrine system, and cause sleep deprivation. All of these factors contribute to the development of obesity.
Nearly 50,000 individuals were involved in their study. The three population-based cohorts are from UK Biobank, HUNT3, and Lifelines established between 2006-2013 in the UK, Norway, and the Netherlands respectively. The participants' waist circumference and body mass index were measured at recruitment. Their central obesity status was subsequently derived.
For all three groups, residential 24-hour road traffic noise (Lden or day-evening-night noise level) was modeled from a standardized European noise assessment framework. Links between road traffic noise and weight were found in Norway and the UK but not in the Netherlands group. Although the study is unable to confirm the causal relationship, their findings echo the conclusions of several previous studies conducted in other European nations.
Co-author Professor Anna Hansell, Director of the University of Leicester's Centre for Environmental Health and Sustainability, said that it has already been recognized that unwanted noise can impact the quality of life of people and disturb our sleep. Recent studies have even raised concerns that traffic noise can influence general health, such as linking it to diabetes and heart attacks.
The authors believe that on an individual level, the top strategy to prevent obesity is to stick to a healthy lifestyle. Dr. Cai mentioned, though, that these results may have some policy implications at the population level. The author opined that introducing environmental policies that focus on reducing people’s exposure to traffic noise can tackle several health problems, including obesity.
The study, led by Professor Hansell, will continue to investigate other sources of noise in the United Kingdom, including aircraft noise, and its impact on the health of people. The researchers believe that long-term follow-up studies would also be valuable in providing more data on how the link between weight and noise functions.
Obesity prevalence worldwide
According to the World Health Organization, worldwide obesity has nearly tripled since 1975. In 2016 alone, more than 1.9 billion adults (18 years and older) were overweight and 650 million of these were obese. The organization considers a person obese if their BMI is greater than or equal to 30.
World Obesity, which represents professional members of the scientific, medical, and research communities dedicated to solving the problems of obesity, likewise shares that the epidemic of obesity is one of the most important public health problems facing the world today. Adult obesity is even more common worldwide than under-nutrition.
Countries with high percentage of adults with obesity includes United States (37.9% men, 41.5% women), Mexico (27.7% men, 38.6% women), Turkey (21.6% men, 35.9% women), Saudi Arabia (24.1% men, 33.5% women), Egypt (24.8%, 48.8% women), and South Africa (11.0% men, 41.0% women), among others.
Why are women more likely to be obese than men?
Economists Anne Case and Alicia Menendez determined common reasons why women are more likely to be obese than men. One is that women who were nutritionally-deprived when they were still children are significantly more likely to be obese when they become adults. On the other hand, men who were nutritionally deprived as children face no greater risk. Economists also found that women’s perception of an “ideal body” is larger than men’s perception of the ideal male body.
Professor Hansell and the team shared that as the world will soon emerge and recover from the pandemic, they encourage the government to look into policies that would manage road traffic better and make public spaces quieter, cleaner, and safer. Dr. Cai went on to say that air pollution is already a health risk but now increasing evidence shows that traffic noise is an equally important public health concern as air pollution.
Noise pollution: statistics
Digital hearing app Mimi Hearing Technologies shares the cities with the worst noise pollution. Guangzhou has been ranked as having the worst levels (1.82) of noise pollution followed by Delhi (1.72), Cairo (1.70), Mumbai (1.67), Istanbul (1.57), Beijing (1.41), Barcelona (1.36), Mexico City (1.32), Paris (1.31), Buenos Aires (1.30), Moscow (1.27), and Shanghai (1.22). The top five quietest cities, on the other hand, are all in Europe: Zurich (0.02), Vienna (0.07), Oslo (0.23), Munich (0.24), and Stockholm (0.26).
Dr. Eoin King, assistant professor of acoustics and author of the book Environmental Noise Pollution, previously shared via The Guardian that noise is an ignored pollutant. Even though there is no set threshold to determine risk, a noise that is above 60 decibels can increase the risk of heart disease. A car measures 70 decibels, plane taking off 120, and a jackhammer 100. He also suggests that noise would be significantly reduced if all vehicles in a city street were electric.
Pollution extends beyond what’s in the water and air. The noise we live with every day is also a growing public and is affecting our hearing. The world needs to take this opportunity to think about how we can reorganize communities and cities to support our health. Road agencies, for instance, can design low noise pavements. European freight trains also use low-noise brake blocks.