Conference_programme: 29: Community noise
Lecture: Assessment of residential exposure to aircraft, road traffic and railway noise in London: Relationship of indoor and outdoor noise
Author(s): Naim Faridah, Fecht Daniela , Hansell Anna, Gulliver John
Summary:
Most epidemiological studies investigating the association between noise exposure and health use modelled outdoor noise estimates as an exposure proxy. This could potentially lead to misclassification of exposure. This study aims to explore the variability of the relationship between indoor and outdoor noise at residential dwellings in London. Measurements were done at 49 homes mostly in the winter and spring seasons when windows are most likely to be closed. Continuous noise measurements were made simultaneously inside and outside each home for three consecutive days using an Optimus CR:171B sound level meter. Selected homes were located close to major roads, railways, under an aircraft flight path or a combination of these. Building surveys and time-activity diaries of the occupants were also collected. The relationship of daytime and night-time indoor and outdoor levels was investigated using linear regression and mixed effects models with random intercepts and slopes on dwelling. The ability of the model to predict indoor noise was investigated. Based on 49 homes measured, mean noise levels recorded were 38.4 dB indoors and 57.7 dB outdoors for LAeq,16h and 30.2 dB indoors and 51.2 outdoors for Lnight. The mean outdoor noise levels were attenuated indoors up to 21.9 dB, with weak correlation between indoor and outdoor noise (LAeq,16h: r=0.34, p=0.02; Lnight: r=0.32, p=0.03). From the linear regression analysis, significant associations were found between indoor and outdoor noise: LAeq,16h (β=0.41, 95% Confidence Interval (CI): 0.08-0.74, p=0.02) and Lnight (β=0.33, 95% CI: 0.04-0.62, p=0.03). Based on mixed-effects model, Lnight has better explanatory power than LAeq,16h which the model predicted 87% of variability in indoor noise. For application in epidemiological studies, this suggests using the Lnight will provide a less biased measure of exposure than daytime noise.
Corresponding author
Name: Ms Faridah Naim
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: United Kingdom
