Old Topics – New Insights Noise Exposure – What's New?

1. Old Topics – New InsightsNoise Exposure – What's New? Hugh W Davies, PhD, CIH School of Environmental Health

2. Noise – a very old topic… OEMAC Conference, Saskatoon, 2010

3. Who is exposed? Occupationally • One of the most ubiquitous of occupational hazards • No routine surveillance • Loss of data • Recent study in US by Tak, et al (2009) • Self-reported exposure (NHANES) • 22 million exposed • Rule of 1/10th’s • ~ 2.2 million in Canada • ~ 200, 000 in BC OEMAC Conference, Saskatoon, 2010

4. Who is exposed? Environmentally • Transportation noise major source of chronic exposure • Road traffic: noise 2 million > 65 dBA • Aircraft noise: 50,000 > 65 dBA • Health Canada • 7.9% very or extremely annoyed by noise • 40-50% of those, transport noise major factor • Less than 20% “not at all” bother by road traffic • Michaud, 2008 OEMAC Conference, Saskatoon, 2010

5. “Non-auditory” effects of Noise • Annoyance • Sleep Disturbance • Hypertension • Ischemic Heart Disease • Learning problems • Accidents • Immune system • Effects on the fetus • Other psychiatric disorders OEMAC Conference, Saskatoon, 2010

6. Noise, stress, and CVD OEMAC Conference, Saskatoon, 2010

7. Experimental Evidence OEMAC Conference, Saskatoon, 2010

8. Don’t you just habituate? • Response rapidly extinguished with repetition in lab • However, response elicited by superimposing a new tone • Response more resilient if source unpredictable, variable • Noise-disturbed sleep • Awakenings subside, but heart rate increase does not extinguish (Greifan et al, 2008) OEMAC Conference, Saskatoon, 2010

9. Epidemiological evidence: The Sawmill Cohort Study • 27,000 male sawmill workers in 14 BC Mills • Employed 1950 – 1998, > 1 year • Linked to vital stats, hospital discharge and MSP • Retrospective noise exposure assessment • N=1900 measurements OEMAC Conference, Saskatoon, 2010

10. Noise & Hypertension Sbihi, et al., Occup Environ Med 2008;65:643–646 OEMAC Conference, Saskatoon, 2010

11. Noise & Hypertension Sbihi, et al., Occup Environ Med 2008;65:643–646 OEMAC Conference, Saskatoon, 2010

12. Sawmill Cohort: Noise and AMI Davies et al., 2005, Epidemiology, 16:25-32 OEMAC Conference, Saskatoon, 2010

13. Sawmill Cohort: Noise and AMI Davies et al., 2005, Epidemiology, 16:25-32 OEMAC Conference, Saskatoon, 2010

14. Hypertension in US Workers • NHANES 1999-2004 • 6307 participants • Self-reported noise exposure • Outcomes • Self-report physician-diagnosed cardiovascular disease • Blood pressure monitoring/blood biochemistry • Results • 2-3 fold risk for angina, AMI, all types of CHD, isolated diastolic hypertension • Higher risk in workers under 50 years Gan, WQ, et al, In press, OEM, 2010 OEMAC Conference, Saskatoon, 2010

15. Our hearing is a choice and dainty sense, And hard to mend, yet soon it may be marred………. …… things that breed it most offense, Blows, fall and noise …… The Medical Poem of Salerno, 1608 OEMAC Conference, Saskatoon, 2010

16. Burden of NIHL OEMAC Conference, Saskatoon, 2010

17. Do hearing conservation programs work? • Weaknesses in most aspects of HCP’s • Yet no broad-based evaluation of HCP’s OEMAC Conference, Saskatoon, 2010

18. UBC HCP Evaluation Study • Examined 316,000 audiograms from 1979-96 • Outcome: 10 dB STS (2,3 & 4 KHz) from baseline • Main indicator variables: participation in HCP, HPD • Co-variates: noise exposure, age, medical Hx, non-occupational exposures • Finding • 42,282 S’s; 5919 STS • RR for HCP = 0.5 • 0.7 – HPD • 0.7 – HCP participation Davies et al, Am J Ind Med (51):923 OEMAC Conference, Saskatoon, 2010

19. UBC Barriers to Noise Controls study • Exposure to noise expected, accepted • Over reliance on HPD • Poor knowledge of engineered noise controls • Engineered noise controls considered impracticable • Low risk perception for noise • Poor knowledge of regulations • Individual responsibility overemphasized • Communication issues • Noise given low priority OEMAC Conference, Saskatoon, 2010

20. ‘The noise and clatter which makes conversation almost impossible on many streets of New York at the present time will be done away with, for horseless vehicles of all kinds are always noiseless or nearly so.’ Sci Am, 1890’s OEMAC Conference, Saskatoon, 2010

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22. Traffic noise and CVD Babisch, 2008 OEMAC Conference, Saskatoon, 2010

23. Noise, air pollution & CHD • Vancouver study analyses in progress – BAQS • All adults 45-85, • N=450,000 • 4-year follow up • LUR air pollution exposure data • Co-variates • Age, gender • SES (from census) • Co-morbidity OEMAC Conference, Saskatoon, 2010

24. BAQS – Road Proximity Study, CHD Gan, Tamburic, Davies et al, Epidemiology 2010;21: 642–649) OEMAC Conference, Saskatoon, 2010

25. UBC Vancouver Noise Mapping OEMAC Conference, Saskatoon, 2010

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27. Future Studies – Early Child Development • Social and environmental factors influence of early child development • Collaboration with Human Early Learning Partnership • Early Development Indictor (EDI) • Sociodemographic covariates • BAQS birth cohort • All kids born 1999-2002 • Maternal exposure • Childhood exposure • Perinatal health • Infant health • Opportunity for life-course study of these early exposures OEMAC Conference, Saskatoon, 2010

28. To summarize… • Noise remains one of our most ubiquitous occupational health hazards • Claims – incidence? – remain high • Lack of will to reduce exposure • Limited data on effectiveness of hearing conservation programs • Noise has important “non-auditory” health effects, including cardiovascular disease OEMAC Conference, Saskatoon, 2010

29. Acknowledgments • Paul Demers, Murray Hodgson, Kay Teschke, Jean Shoveller, Mike Brauer • Hind Sbihi, Musarrat Nahid, Amber Louie, Kim McLeod • Sarah Chiarello, Kathleen McLean • Christine Harrison, Heather Gillis OEMAC Conference, Saskatoon, 2010

30. Questions? OEMAC Conference, Saskatoon, 2010