The impact of a lesser known environment hazard – noise
A recent study conducted by the Swiss Tropical and Public Health Institute and the Barcelona Institute for Global Health recently found that noise increases the risk of being overweight and obesity.
By CASSANDRA GOMES-HOCHBERGMan lying in bed with pillow suffering from noise (photo credit: INGIMAGE)
Road traffic causes not only air pollution, but another environmental hazard which has proven to be more prevalent and hazardous than originally thought. Noise, not commonly regarded as an environmental pollutant, can lead not only to concentration disturbance, nervousness and hearing loss, as is commonly known, but to much more serious health problems.A recent study conducted by the Swiss Tropical and Public Health Institute and the Barcelona Institute for Global Health recently found that noise increases the risk of overweight and obesity.Exposure to noise – traffic noise specifically – was associated with direct measures of abdominal fat (waist circumference and central obesity) and adiposity (percentage of body fat). According to the study, reducing the exposure to traffic noise could substantially reduce the obesity epidemic and decrease morbidity.The study was conducted in Switzerland where, according to data published by the OECD in 2015, the road traffic density is 854 vehicles per kilometer of road, slightly above the OECD average of 773. Israel comes second in road traffic density among OECD countries – after South Korea – with an average of 2,730 vehicles/km, so it can be assumed that the noise from such traffic is significantly higher. South Korea has the highest density by far, with 13,809 vehicles/km – five times as much as Israel, and almost 18 times as much as the OECD average.Not only is the number of vehicles responsible for noise levels, but their type, speed, slope, vehicle conditions and flow character – intersections where traffic is “stop and go,” for example, have higher noise levels. A report published by Israel’s Environmental Protection Ministry showed that from 2000 to 2014, half of the population was exposed to noise levels of over 60 dBa (A-weighted decibels), which is considered excessively noisy. Some 23% were exposed to noise of over 65 dBa and 8.1% to noise over 70 dBa.Noise leads to stress reactions that trigger the endocrine and autonomous nervous systems, especially during resting periods while sleeping. Further studies in the field have shown the role that repeated night time noise exposure contributes to increasing stress hormones – specifically cetecholamines – blood pressure, heart rate and endothelial dysfunction.These effects trigger oxidative stress, which is an imbalance between the production of free radicals and the body’s ability to counteract their harmful effects through antioxidants.Studies from the same group cohort have previously evaluated the association between transportation noise and arterial stiffness. Long-term exposure to railway noise, not road noise, affected the participants in the study, especially those who live in the vicinity of highly intermittent night time noise.
