Individual daytime noise exposure in different microenvironments

Abstract

Background: Numerous studies showed that chronic noise exposure modeled through noise mapping is associated with adverse health effects. However, knowledge about real individual noise exposure, emitted by several sources, is limited.

Objectives: To explain the variation in individual daytime noise exposure regarding different microenvironments, activities and individual characteristics.

Materials and methods: In a repeated measures study in Augsburg, Germany (March 2007-December 2008), 109 individuals participated in 305 individual noise measurements with a mean duration of 5.5h. Whereabouts and activities were recorded in a diary. One-minute averages of A-weighted equivalent continuous sound pressure levels (Leq) were determined. We used mixed additive models to elucidate the variation of Leq by diary-based information, baseline characteristics and time-invariant variables like long-term noise exposure.

Results: Overall noise levels were highly variable (median: 64 dB(A); range: 37-105 dB(A)). Highest noise levels were measured in traffic during bicycling (69 dB(A); 49-97 dB(A)) and lowest while resting at home (54 dB(A); 37-94 dB(A)). Nearly all diary-based information as well as physical activity, sex and age-group had significant influences on individual noise. In an additional analysis restricted to times spent at the residences, long-term noise exposure did not improve the model fit.

Conclusions: Individual exposures to day-time noise were moderate to high and showed high variations in different microenvironments except when being in traffic. Individual noise levels were greatly determined by personal activities but also seemed to depend on environmental noise levels.

Keywords: Activity diary; Epidemiology; Microenvironments; Noise exposure; Personal exposure.