Table of Contents
By Heather Pyle
W hat comes to mind when you think of pollution? Dirty rivers clogged by rubbish? Oil spills at sea? Smog over the city? These are often the first things we think of, but there are other forms of pollution – loud and persistent noise, bright light when it should be dark or fumes in our local streets. While effects of pollution on the natural environment have often been highlighted, research has also identified potential negative health effects.
Noise Pollution
Noise pollution, unwanted or excessive sounds in the environment, often cause annoyance and headaches but can potentially cause other harm, affecting hearing, sleep and heart health. Loud noise (particularly above 85 decibels) or prolonged exposure can cause hearing loss or persistent ringing in the ears. Examples of the noise levels of some common sounds are shown in Table 1. Noise above 120 decibels is not considered safe for hearing for any duration.
Sleep disturbance is common amongst people exposed to noise. During sleep, our ears continue to pick up noises that our brains process, affecting sleep quality. Poor sleep can lead to daytime sleepiness, poor concentration, impaired memory and reduced performance in work or other activities. Research also suggests that exposure to noise pollution affects children’s attention and reading performance.
In addition to these effects, noise pollution is associated with high blood pressure and heart disease, most likely from persistent activation of stress responses which increase the heart rate and blood pressure, as well as altering metabolism. It is not currently known how much noise exposure will result in these problems. About 70 percent of environmental noise in urban areas is from road traffic. Shift workers, children, elderly people or those with chronic health problems are more vulnerable to the effects of noise pollution.
Light Pollution
Light pollution is the excessive or inappropriate use of outdoor artificial light and may be the least frequently recognised of these forms of pollution.
It is a growing global problem. Huge areas, particularly in developed countries, are brightly lit at night (see The World Atlas of Night Sky Brightness: https://cires.colorado.edu/Artificial-light). Light pollution has been associated with many health effects and disrupts our natural circadian rhythms which regulate many body functions and the sleep-wake cycle. Light exposure reduces melatonin production, resulting in poor sleep and fatigue, as well as altering hormone systems which affect metabolism, mood, anxiety and stress. Research suggests that light pollution may also be associated with increased risks of obesity, heart disease, diabetes, breast cancer and possibly other cancers.
Air Pollution
Air pollution may be the most well-known, occurring when the atmosphere is contaminated by dust, fumes and smoke in sufficient quantities or for long enough that it can harm health. Most evidence relates to particulate matter and gases like carbon monoxide, sulphur dioxide, nitrogen dioxide and ozone.
All body systems may be affected by air pollution depending on the amount and duration of exposure. Short-term exposure to high levels of pollutants can lead to breathing difficulties, respiratory infections and exacerbation of asthma. With long-term exposure, fine particles may be absorbed into the blood stream from the lungs and travel to organs increasing the risk of diseases such as stroke, heart disease, chronic obstructive pulmonary disease and cancer.
Minimising Pollution
Reducing pollution is a shared responsibility. In Victoria, the Environment Protection Act 2017 outlines a general duty for all individuals and businesses to minimise activities that could harm the environment or public health.
Further research will help us better understand pollution’s effects and improve strategies to reduce risks. Everyone has a role to play in protecting both the environment and human health.
