Characterizing temporal trends in populations exposed to aircraft noise around U.S. airports: 1995-2015

Abstract

Background: Aircraft noise is a key concern for communities surrounding airports, with increasing evidence for health effects and inequitable distributions of exposure. However, there have been limited national-scale assessments of aircraft noise exposure over time and across noise metrics, limiting evaluation of population exposure patterns.

Objective: We evaluated national-scale temporal trends in aviation noise exposure by airport characteristics and across racial/ethnic populations in the U.S.

Methods: Noise contours were modeled for 90 U.S. airports in 5-year intervals between 1995 and 2015 using the Federal Aviation Administration's Aviation Environmental Design Tool. We utilized linear fixed effects models to estimate changes in noise exposure areas for day-night average sound levels (DNL) of 45, 65, and a nighttime equivalent sound level (L_night) of 45 A-weighted decibels (dB[A]). We used group-based trajectory modeling to identify distinct groups of airports sharing underlying characteristics. We overlaid noise contours and Census tract data from the U.S. Census Bureau and American Community Surveys for 2000 to 2015 to estimate exposure changes overall and by race/ethnicity.

Results: National-scale analyses showed non-monotonic trends in mean exposed areas that peaked in 2000, followed by a 37% decrease from 2005 to 2010 and a subsequent increase in 2015. We identified four distinct trajectory groups of airports sharing latent characteristics related to size and activity patterns. Those populations identifying as minority (e.g., Hispanic/Latino, Black/African American, Asian) experienced higher proportions of exposure relative to their subgroup populations compared to non-Hispanic or White populations across all years, indicating ethnic and racial disparities in airport noise exposure that persist over time.

Significance: Overall, these data identified differential exposure trends across airports and subpopulations, helping to identify vulnerable communities for aviation noise in the U.S.

Impact statement: We conducted a descriptive analysis of temporal trends in aviation noise exposure in the U.S. at a national level. Using data from 90 U.S. airports over a span of two decades, we characterized the noise exposure trends overall and by airport characteristics, while estimating the numbers of exposed by population demographics to help identify the impact on vulnerable communities who may bear the burden of aircraft noise exposure.

Keywords: Environmental justice; Geospatial analyses; Vulnerable populations.

Fig. 1

Sample of U.S. airports (n = 90) included in the study.

Fig. 2. Temporal trends in mean aircraft noise contour size for 90 U.S. airports.

dB(A) A-weighted decibels, DNL day–night average sound level, L_night nighttime equivalent sound level.

Fig. 3. Temporal trends in residents exposed to aircraft noise around 90 U.S. airports.

A Total counts and B normalized by tract total population^a. ^aNormalized by tract total population: denominator is the total population (e.g., no. of total population exposed in tracts / no. of total population living in tracts around airports). dB(A) A-weighted decibels, DNL, day–night average sound level, L_night nighttime equivalent sound level.

Fig. 4. Temporal trends in residents exposed to aircraft noise around 90 U.S. airports by Hispanic/Latino status.

Presented as A normalized by tract Hispanic/Latino or non-Hispanic/Latino populations^a, B total counts, and C normalized by tract total population^b. ^aNormalized by tract sub-population: denominator is the subgroup population (e.g., no. of Hispanics exposed in tracts / no. of Hispanics living in tracts around airports). ^bNormalized by tract total population: denominator is the total population (e.g., no. of Hispanics exposed in tracts / no. of total population living in tracts around airports). dB(A) A-weighted decibels, DNL day–night average sound level, H/L Hispanic/Latino, L_night nighttime equivalent sound level.

Fig. 5. Temporal trends in residents exposed to aircraft noise around 90 U.S. airports by race.

Presented as A normalized by tract race group population^a, B total counts, and C normalized by tract total population^b. Note: Lacking 2005 race data due to inconsistent reapportionment of “Other Alone”. ^aNormalized by tract sub-population: denominator is the subgroup population (e.g., no. of White alone exposed in tracts / no. of White alone living in tracts around airports). ^bNormalized by tract total population: denominator is the total population (e.g., no. of White alone exposed in tracts / no. of total population living in tracts around airports). AA African American, AI/AN American Indian/Alaska Native, dB(A) A-weighted decibels, DNL day–night average sound level, L_night nighttime equivalent sound level, NH/PI Native Hawaiian/Pacific Islander, 2+ two or more races.