TagWHO(6)

A Des Moines resident's formal comment argues that the Seattle-Area Metroplex Environmental Impact Statement's noise analysis is legally inadequate because it relies solely on a federal FAA noise threshold rather than Washington State's own multi-factor significance standard. The comment contends that the standard noise metric used (DNL) masks the real impact of roughly 96 additional daily flights projected by 2037, since it averages out individual disturbance events rather than counting them. The commenter calls for supplemental analysis using alternative metrics—such as single-event sound levels and nighttime averages—supported by peer-reviewed health studies linking aircraft noise to sleep disruption and cardiovascular harm.

This document explains how aircraft noise is measured using decibel-based metrics such as DNL, CNEL, and SEL, and highlights that the FAA's accepted noise threshold of 65 dB exceeds the World Health Organization's recommended limits of 50–55 dB outdoors and 30–35 dB indoors. It also notes that standard metrics like SEL fail to capture the cumulative impact of repeated aircraft overflights. The international aviation body ICAO recommends a four-part 'Balanced Approach' to managing airport noise, encompassing noise reduction at the source, land-use planning, operational procedures, and operating restrictions.

This 2022 WHO compendium brings together guidance from the World Health Organization and other United Nations agencies on the links between human health and environmental factors. It covers topics such as air quality, water, sanitation, and climate-related health risks, providing policymakers and practitioners with a consolidated reference for evidence-based standards. The document is produced in collaboration with UNDP, UN Environment, and UNICEF.