Causes and Effects of Noise Pollution (College Board AP® Environmental Science): Study Guide

Noise pollution is measured in decibels (dB) and is defined as harmful or annoying levels of noise in an environment

• Noise pollution is sound at levels high enough to cause physiological stress and hearing loss

It is an unwanted, ever-present, invisible danger to both organisms and humans

Centers for Disease Control (CDC) and the National Institute for Occupational Safety and Health (NIOSH) state that regular noise above 85 dB (e.g. a food blender) will damage a person's hearing

Noise levels range from breathing at 0 dB to normal conversation at around 60 dB, with the call of the sperm whale at 230 dB

The Haleakalā crater on Maui, Hawaii, is known as the 'quietest place on Earth,' at just 10 dB

Sources of noise pollution can be land-based or aquatic

Most common land-based noise pollution comes from:

• large urban areas—movement of people, talking, dragging luggage, grocery carts, cafe's, diners, etc.

• transport—vehicles, sirens, car horns, trains and aircraft take off and landing

• construction—jackhammers, drilling, cement mixers, hammering, sawing, etc.

• industry—heavy machinery, power tools, ventilation systems, conveyor belts, pumps, pneumatic equipment, etc.

• night activities—nightclubs, bars, parties, etc.

• energy production—wind turbines, power stations, dams, etc.

Sound travels farther in water and aquatic noise pollution arises from

• propellers of ships

• offshore wind turbines

• sonar equipment on ships, fishing vessels, submarines, excavation vessels, etc.

  • sonar sounds can be as loud as 235 dB and travel hundreds of miles underwater

• oil rigs and drilling

• seismic surveys

• underwater construction, such as laying pipes, pile driving, caissons, and cofferdams, etc.

Noise pollution can stress and deafen animals

Species that rely on echolocation for their communication, feeding and orientation can be harmed

• Bats have difficulty finding their food

• Birds have to alter their singing pitch or sing at different times to attract mates

• Loud noises can disrupt the echolocation of marine animals like whales and dolphins, making it harder for them to migrate, navigate, find food, and communicate, sometimes leading to stranding

Underwater: propellers and sonar have disrupted whale and dolphin communication and caused hearing loss

• Whale pods have changed their migratory routes to avoid shipping routes and sonar

Noise pollution has a range of impacts on humans, including:

• Permanent hearing loss-long-term exposure to 100 dB or more (e.g. construction work) damages the inner ear and leads to sensorineural hearing loss

• Disturbed sleep leading to stress and anxiety

• In adults, it contributes to high blood pressure, heart disease, and impaired thought processing

• Negative effects on child development, such as reading difficulties, speech delays, stress and hyperactivity