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Year : 2012  |  Volume : 14  |  Issue : 61  |  Page : 313--314

Combined Exposures: An update from the International comission on biological effects of noise

Tony Leroux1, Ronny Klaeboe2,  
1 School of Speech Language Pathology and Audiology, Faculty of Medicine, University of Montreal, C.P. 6128, succ. Centre ville, Montreal (Quebec), Canada
2 Department of Safety, Security and Environment, Transportøkonomisk Institutt, Gaustadalléen 21, 0349 Oslo, Norway

Correspondence Address:
Tony Leroux
School of Speech Language Pathology and Audiology, Faculty of Medicine, University of Montreal, C.P. 6128, succ. Centre ville, Montreal (Quebec)


International Commission on Biological Effects of Noise (ICBEN) Team 8 deals with the effects of combined «DQ»agents«DQ» in the urban and work place settings. Results presented at the ICBEN conference indicate that some pesticides, more specifically the organophosphates, and a wider range of industrial chemicals are harmful to the auditory system at concentrations often found in occupational settings. Effects of occupational noise on hearing are exacerbated by toluene and possibly by carbon monoxide. Several of the chemicals studied found to be potentially toxic not only to hair cells in the cochlea but also to the auditory nerve. In urban environments, team 8 focuses on additive and synergetic effects of ambient stressors. It was argued that noise policies need to pay attention to grey areas with intermediate noise levels. Noteworthy is also stronger reactions to vibrations experienced in the evening and during the night. An innovative event-based model for sound perception was presented.

How to cite this article:
Leroux T, Klaeboe R. Combined Exposures: An update from the International comission on biological effects of noise.Noise Health 2012;14:313-314

How to cite this URL:
Leroux T, Klaeboe R. Combined Exposures: An update from the International comission on biological effects of noise. Noise Health [serial online] 2012 [cited 2022 Nov 27 ];14:313-314
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Full Text

 ICBEN Conference Presentations

Current European Commission (EC) noise policies focus on the "black" areas where noise exposure lies above 65 dBA. As a result of Swedish research, the soundscape movement, and the incorporation of quiet or "green" areas in the European Noise directive urban areas with noise levels below 55 dBA have also received attention. Ronny Klae argued that gray areas between 55 and 65 dB should not be neglected, and needed a research focus. Whereas efforts addressing black areas have met with some success, both Norwegian and Dutch time series show that the overall noise problem is getting worse due to the temporal and spatial expansion of gray areas. Climate motivated urban densification processes also tend to locate new dwellings in more heavily noise exposed areas. Klaeboe also warned that limiting noise annoyance as a health problem to only "serious" or "highly" annoyed persons could result in a reduction in the calculated benefits of undertaking noise mitigation efforts, and be of disservice to the very group one wanted to prioritize.

In a complementary approach Dick Botteldooren and colleagues adapt a broader approach to "traffic livability"-quality of life factors that are influenced by traffic, not only at home, but also in commuting, and other life arenas/locations. Results indicate that it is possible to obtain more holistic indicators of traffic livability, and relate these to people's perception of the urban environment.

 Noise and Chemicals Substances

Only two papers were presented at this year's conference on this topic. Leroux and colleagues used a weight of evidence approach to assess the ototoxic potential of industrial chemicals at concentrations relevant for the occupational setting. Their work indicates that lead, styrene, toluene, and trichloroethylene are ototoxic and ethyl benzene, n-hexane, and xylene are possibly ototoxic. When looking at interaction with noise exposure, toluene, and possibly carbon monoxide appear to exacerbate noise-induced hearing impairment. Toluene interacts with noise to induce more severe hearing losses than noise alone. Robidoux-Léonard and colleagues examined the interaction between noise and organophosphate pesticides on a small group of farm workers (n = 5). Workers exposed to both contaminants showed a significantly more pronounced hearing loss at 8 kHz and worst hearing threshold for a wider frequency range between 4 and 9 kHz. A tendency for a larger proportion of abnormal contralateral suppression of otoacoustic emissions was observed in workers exposed to both contaminants at 1.4 and 2 kHz. Given the very small sample size, these results need further confirmation.

 Noise and Vibrations

This year's ICBEN conference brought a very welcome set of papers on methods for obtaining dwelling vibration measures, on annoyance from vibrations alone and in combination with noise. Gennaro Sica presented different methodologies for estimating the exposure from vibration sources in residential settings. Different sources (rail, construction, internal) require distinct measurement and estimation strategies. David Waddington presented exposure-annoyance relationships from the study showing a clear increase in annoyance reactions from vibration with increasing noise exposure.

Current EC policy is to transfer freight from road to rail to relieve congested road systems and reduce the emissions of local air pollutants and green house gases. This will unavoidably increase the number of night-time rail freight movements. However, Eulalia Peris presented results from the DEFRA study showing that residents react stronger to vibrations occurring during the nighttime.

 Noise and Air Pollution

Klaeboe summarized Norwegian research into combined impacts from road noise and air pollution. Relationships between indicators of air pollution and annoyance from air pollution show narrow bands of error and are of the same quality as those obtained for road traffic noise in Norway. He also noted exposure that annoyance results from several smaller European studies are similar to those found in Norway. Annoyance reactions are prevalent at ambient air pollution levels commonly occurring in European cities.

Bente Oftedal explored the correlation between road traffic noise at the most exposed facade and NO 2 in a separate Oslo-study. The correlation between road traffic noise at most exposed façade and NO 2 was 0.42-0.43 and 0.21-0.23 between rail noise at most exposed façade and NO 2 . The correlation between both sources of traffic noise at least noise exposed façade and NO 2 was even lower (rs = 0.06-0.07). This indicates that the exposure data should be well suited to differentiate between health impacts caused by each of the exposures alone and in combination.

 Sound Perception

"Global" impact measures such as average annoyance experienced over a whole year are often related to exposure metrics correspondingly averaged over a long period of time. In a novel and refreshing approach Annelies Bockstael and colleagues deconstruct annoyance by considering annoyance as a result of distinct noise events with time resolution in themillisecond range. The perception of the sound environment is seen as resulting from series of simultaneous and consecutive events. The effects of these individual events are modeled with the help of neuro-physiologically motivated gating and saturation functions. Consecutive similar sound events give rise to saturation effects modeled as a heightening the threshold for perceiving following events. This is an approach that has the potential to improve our understanding of exposure annoyance relationships from different noise sources, the perception of combined noise sources, and if expanded to annoyance events in general, to human responses to mixed ambient stressors. However, it then becomes necessary to establish relationships between contextually dependent micro-scale annoyance experiences and more global overall measures of annoyance.

 Full Reviews from 2014

The team 8 meeting in London concluded that due to the scarcity of studies on combined impacts, a 6-year summary period could be more appropriate than a 3 year one. In the environmental setting, [1] Lercher provided a fairly recent review, whereas the studies from references [2],[3],[4],[5] also provided the same in the workplace setting. Team 8 will produce 6-year summaries starting in 2014. New chair of Team 8 is Tony Leroux from University of Montreal. Co-chair is Ronny Klaeboe from Institute of Transport Economics in Oslo.


1Lercher P. Combined noise exposure at home. In: Nriagu JO, editor. Encyclopedia of Environmental Health. Burlington: Elsevier Science and Technology; 2011. p. 764-77.
2Johnson AC, Morata TC. Occupational exposure to chemicals and hearing impairment. The Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals. Nordic Expert Group. Gothenburg. Arbete och Hälsa 2010;44:1-177.
3European Agency for Safety and Health at Work. Combined exposure to noise and ototoxic substances. Luxembourg: European Agency for Safety and Health at Work; 2009. p. 60.
4Vyskocil A, Leroux T, Truchon G, Lemay F, Gagnon F, Gendron M, et al. Effect of chemical substances on hearing - Interactions with noise. Studies and research projects/Report R-747. Montréal, Institut Robert-Sauve de recherche en santé et en sécurité du travail; 2012. p. 34.
5Sliwinska-Kowalska M. Combined exposures to noise and chemicals at work. In: Nriagu JO, editor. Encyclopedia of Environmental Health. Burlington: Elsevier Science and Technology; 2011. p. 755-63.