The Health Effects of Road Traffic – A Brief Overview

N. Meaghan Ferguson, Robert J. Moriarity, Frederic Gagnon and Melanie J. McCavour

Scientific research conducted over the last 30 years has accumulated evidence for the numerous impacts of road traffic on health. These include increased risk of heart attack, increased blood pressure, asthma, wheezing in infants, sleep deprivation, reduced birth weights, and psychological effects such as stress, anxiety, and diminished memory capacity. These health effects particularly impact people of lower socio-economic status because they are more likely to be exposed to the worst air quality, the highest noise levels, and overall poor environmental quality than those with higher socio-economic status. The effects are more pronounced with increasing proximity to highways, where a 200-meter buffer from the highway has been identified as a zone of elevated health risks. This has important implications for the environmental assessment of road projects. For example, air quality in the vicinity of Montreal’s Turcot Interchange cannot be predicted on the basis of air quality stations located several kilometers away, as was attempted in the Environmental Assessment report presented by the Ministère des Transports du Québec.

Introduction

This chapter provides an overview of the impacts of road traffic on the health of residents living within a 200-meter distance from a major roadway based on relevant scientific literature. The distance of approximately 200-meters has been identified as the width of the buffer where negative health effects due to air pollution and noise have clearly been demonstrated. The emphasis of this chapter is on the effects of noise and air pollution on quality of life as well as the link with socioeconomic status.

Noise and Vibrations

Since the late 1970s, research has shown a strong influence of noise, the invisible pollutant, on physical and mental health. Detailed investigations have revealed a strong connection between noise and cardiovascular, mental, and other health effects.

Road noise includes any noise generated by vehicles moving on a road surface. Noise could emanate from the vehicles themselves through engine noise or braking, and from the contact of the tires on the road surface. The main factors to consider are the volume and speed of traffic, and the number of trucks in the traffic flow; trucks generally create more noise than the typical car. Road noise levels also depend on how close the perceiver is to the road (Washington State Department of Transportation 2009).

Exposure to road noise at an average distance of 200-meters or less poses a risk to human health (Genereux et al. 2007). Any amount of noise that exceeds 50 decibels (dBA) for more than 24 hours is enough to cause stress on the physical and mental well being of those living in affected areas (Bluhm 2004). Furthermore, with the high cost of property involved in highways and road construction, it is not always feasible to construct buffer zones around roads; therefore, residential areas often end up in this 200-meter area. Certainly, this is the case with Montreal’s Village des Tanneries, a small neighbourhood immediately abutting the Turcot Interchange: it was there long before this structure and the Ville Marie expressway (Autoroute 720) were constructed.

Of those individuals living near a road or highway that has a continuous noise level over 50 dBA, with periodic maximums reaching 70 dBA, there is an approximately 1.5 times increase in the risk of a heart attack, and for those individuals living there more than 10 years there is a 2-fold risk increase (Babisch et al. 2005). The risk of hypertension increases for those individuals living in the vicinity of a busy highway by 1.4 times per 5 dBA increase, with a maximum risk increase of approximately 2.5 times (Bluhm et al. 2007). The literature supports the causal link between road noise and cardiovascular problems; therefore, it is safe to conclude that chronic exposure to high levels of traffic noise increases the risk of physical health problems.

The continuous noise of a highway clearly has a profound effect on physical health; however its effects on mental health are also widely noted (Lercher 1996; Muller-Wenk 2002). Experts agree that anyone living within 200-meters from a busy road or highway may have their mental health jeopardized after residing in the area for a period of more than one year. Impacts on health from noise-induced mental stress can result in memory loss, that is especially noticeable in children and long-term residents, an increased level of anxiety and depression, and in some cases elevated levels of substance abuse (Passcher 2000). Studies have also noted that those affected may not notice continuous noise after a certain amount of time, however the effects on mental health are present (Stansfield 2000).

The implications from non-auditory noise (i.e., vibrations) on the health of those living near a busy road or highway are still under investigation; however, studies show a general trend of changes in hormone levels, due to the constant vibration of the ground from a continuous source of vehicles (Lercher 1996; Matheson et al. 2003).

Respiratory health

Air quality is known to be poor within 200-meters of a highway, and very poor within 50 meters (Genereux et al. 2007). To accurately gauge air quality near a highway, measurement must systematically be done at is needed in proximity to the source of pollutants, the highway itself. Interpolated data from a limited number of air quality stations that are located more than 1000 meters away from a highway will not give an adequate representation of air quality in close proximity to highways or neighborhoods at ground level (Cao 2006). As a consequence, the data from a limited number of air quality stations in Montreal is insufficient to estimate variations in air quality at differing distances from highways.

There is a relationship between traffic pollutants and an increased incidence of asthma and respiratory allergies (Nillson 1999; Lewis 2000; Puliafito 2002; Holguin 2007). Typically, investigators have measured distance from highways to residential areas to establish a link with hospital admission records for asthma. One major conclusion of these studies is that low-income neighborhoods near highways tend to have higher per capita rates of hospital admission for respiratory problems (Delfino et al. 1997; Maupin 2004); and it is often suggested that this is due to the higher density of highways in low-income neighborhoods. In addition, there are experimental studies relating the concentration of particulate matter (PM), fine airborne particles, to non-asthmatic respiratory problems (Heinrich 2004; Brunekeef 2005; Morganstern 2008).

Asthma is a serious health hazard and has been the focus of many traffic pollution studies; several have concluded that traffic exposure and asthma are related (Rosas 1998; Hoek 2001; Chang 2009). Two variables that have been used are proximity to a highway and traffic volume. Montreal studies applying these variables show an increased occurrence of asthma in the elderly as well as in young children (Delfino et al. 1997; Hoek, 2001; Gehring 2002; Holguin 2007). Respiratory ailments in all age groups are higher within 200-meters of a major highway or road, with the highest rate of occurrence being reported within 50 to 75 meters from the highway (Van Vliet 1997; Nicolai 2003; Ryan et al. 2005). Infants living in close proximity to a major roadway have a higher incidence of wheezing as compared to unexposed infants (Ryan et al. 2005).

Many studies have demonstrated the relationship between air pollutants and respiratory problems. A recent study measured the amount of exhaled nitrogen monoxide (NO) in humans and concluded that it was the most reliable and measurable pollutant for explaining the relationship between respiratory difficulties and traffic (Holguin et al. 2007). This is of interest because exhaled NO can be used to estimate inhaled NO and is a good predictor of traffic pollutant levels (Holguin 2005). Other studies have found that of all the air pollutants responsible for wheezing in infants, only nitrogen dioxide (NO2) and NO showed significant correlations with the prevalence of asthma; as well, asthma-related emergency room visits were positively correlated to these two air pollutants (Andersen 2008; Garty et al. 1998). Additionally, PM2.5 (extremely fine airborne particles) in automobile exhaust is considered to be the most hazardous PM because as it is inhaled it is easily absorbed in the lungs. It may be that PM2.5 and NO are equally responsible for respiratory disorders; however there may be additional unidentified air pollutants that are also responsible for respiratory problems.

Sleep and Quality of Life

Respiratory health problems and noise related to large roadways are significant contributors to sleep problems (Sleep in America Poll 2007). The quality of sleep is directly related to quality of life, defined as an individual's emotional, social and physical health. A lack of sleep is associated with an increase in the risk of prostate cancer, hypertension and type II diabetes (Kakizaki et al. 2008; Mehmet Birhan et al. 2008; Javaheri et al. 2008; Beihl et al. 2009; Tasali et al. 2009). It has been shown that decreased sleep in early childhood is also associated with an increased risk of obesity (Touchette et al. 2008). Several studies have demonstrated that sleep deprivation resulted in decreased mental performance and hyperactivity in children (Pilcher and Huffcuff 1996; Touchette et al. 2007). Overall, these physical and psychological factors have been shown to affect sleep and, hence, directly affect individual’s emotional, social and physical health.

The effects on physical and mental health translate into direct and indirect social costs. The annual economic impact of accidents related to sleep deprivation has been estimated at 67 to 88 billion Canadian dollars (Leger 1994).

In addition, the economic loss from decreased work productivity and increased vulnerability to sickness in the province of Quebec was estimated at 6.5 billion Canadian dollars (Daley et al. 2008).

Highways, Health and Socioeconomic Status

In general, scientific findings suggest that neighborhoods do have an effect on health status, above and beyond individual socio-demographics and behavioral characteristics (Ross, Tremblay & Graham 2004; Feldman & Steptoe 2004). As neighborhood socio-economic status increases, so does the relative benefit to health (Feldman & Steptoe 2004; Pickett & Pearl 2001). The city of Montreal has been found to be the most segregated and unequal in terms of income in Canada (Ross, Tremblay & Graham 2004). Overall, it has been predicted that urban neighborhoods in Canada are becoming gradually more homogenous in terms of their societal and health status (Ross, Tremblay & Graham 2004). This is important because it shows that as the gap between the rich and poor increases, the impact on the health of people of low socioeconomic status will also enlarge.

Studies show that there is a distinct relationship between health, proximity to highways and socioeconomic status. This is due to the fact that people with low incomes tend to reside near highways because property is less expensive and this in turn negatively impacts their health (Genereux et al. 2007). In general, people of lower socio-economic status are more likely to be exposed to the most noise, the worst air quality, and overall poorer environmental conditions than those with higher socioeconomic status (Link & Phelan 2002; Evans & Kantrowitz 2002). Households with incomes below $10,000 have been found to have average sound exposure levels more than 10 dBA higher than households above $20,000 annual income (Evans & Kantrowitz 2002). This is coupled with the fact that short-term exposure to fine PM exacerbates existing pulmonary and cardiovascular disease; and long-term exposure increases the risk of cardiovascular disease and death (Brugge, Durant & Rioux 2007; Feldman & Steptoe 2004; Evans & Kantrowitz 2002). These studies show that in general, low-income neighborhoods are more likely to have a higher occurrence of health issues than those individuals living in higher income neighborhoods.

Economically disadvantaged individuals are disproportionately exposed to traffic related pollutants which have been associated with increased respiratory morbidity and mortality as they often reside along major roads (Smargiassi 2007). Several studies link socioeconomic status and traffic intensity to low birth weight in newborns (Subramanian et al 2006; Smargiassi 2007; Zeka, Melly & Schwartz 2008). One study linking mothers’ educational attainment, newborns’ birth weight and distance to highway found that mothers with a lower education who lived closer to a highway were more likely to give birth to newborns with low birth weight than mothers with a higher education who reside in a similar area (Zeka, Melly & Schwartz 2008). The increased vulnerability to air and noise pollution may be due to low socioeconomic status, whereby residents are more likely to be exposed to poor living conditions, occupational hazards, poorer nutrition and psychological stress than people of a higher socioeconomic status (Zeka, Melly & Schwartz 2008). Overall, it is suggested that the socioeconomic status, and its correlation to environmental and neighborhood quality, has a profound impact on health.

Conclusion

The noxious chemicals and sounds coming from automobiles on high-density roads have detrimental effects on human health for those living within the close proximity of these roads. The risks associated with proximity to highway are numerous: there is an elevated risk of respiratory, mental and sleep disorders, and an overall decrease in health and quality of life. Overall, these findings have important implications for the environmental assessment and construction of road projects.

The Ministère des Transports du Québec (MTQ) proposal will place lanes of traffic in close proximity to residential neighborhoods. The data used by the MTQ to assess the baseline air quality is inadequate due to the small number of air quality stations and their large distance from the Turcot Interchange. On average, the air quality stations are five kilometers away from the interchange itself (own calculations). Such a large-scale interpolation cannot predict higher concentrations of pollutants that are expected to occur within 200-meters of Autoroute 720, which connects to the Turcot Interchange and borders the residential neighborhood of the Village des Tanneries. 

Acknowledgements: We wish to extend our thanks to Dr. Jochen Jaeger and François Thérien for their input and contribution.

References

Andersen, Z. J., S. Loft, M. Ketzel, M. Stage, T. Scheike, M. N. Hermansen, and H. Bisgaard. "Ambient Air Pollution Triggers Wheezing Symptoms in Infants." Thorax 63, no. 8 (2008): 710-6.

Babisch, W. F., B. Beule, M. Schust, N. Kersten, and H. Ising. "Traffic Noise and Risk of Myocardial Infarction." Epidemiology 16, no. 1 (2005): 33-40.

Beihl, D. A., A. D. Liese, and S. M. Haffner. "Sleep Duration as a Risk Factor for Incident Type 2 Diabetes in a Multiethnic Cohort." Annals of Epidemiology 19, no. 5 (2009): 351-7.

Bluhm, G., E. Nordling, and N. Berglind. "Road Traffic Noise and Annoyance--an Increasing Environmental Health Problem." Noise and Health 6, no. 24 (2004): 43-9.

Bluhm, G. L., N. Berglind, E. Nordling, and M. Rosenlund. "Road Traffic Noise and Hypertension." Occupational and Environmental Medicine 64, no. 2 (2007): 122-26.

Brugge, D., J. L. Durant, and C. Rioux. "Near-Highway Pollutants in Motor Vehicle Exhaust: A Review of Epidemiologic Evidence of Cardiac and Pulmonary Health Risks." Environmental Health 6 (2007): 23.

Brunekreef, B., and J. Sunyer. "Asthma, Rhinitis and Air Pollution: Is Traffic to Blame?" European Respiratory Journal 21, no. 6 (2003): 913-15.

Cao, J., M. F. Valois, and M. S. Goldberg. "An S-Plus Function to Calculate Relative Risks and Adjusted Means for Regression Models Using Natural Splines." Computer Methods and Programs in Biomedicine 84, no. 1 (2006): 58-62.

Chang, J., R. J. Delfino, D. Gillen, T. Tjoa, B. Nickerson, and D. Cooper. "Repeated Respiratory Hospital Encounters among Children with Asthma and Residential Proximity to Traffic." Occupational and Environmental Medicine 66, no. 2 (2009): 90-8.

Daley, M., C. M. Morin, M. LeBlanc, J. P. Gregoire, and J. Savard. "The Economic Burden of Insomnia: Direct and Indirect Costs for Individuals with Insomnia Syndrome, Insomnia Symptoms, and Good Sleepers." Sleep 32, no. 1 (2009): 55-64.

Delfino, R. J., A. M. Murphy-Moulton, R. T. Burnett, J. R. Brook, and M. R. Becklake. "Effects of Air Pollution on Emergency Room Visits for Respiratory Illnesses in Montreal, Quebec." American Journal of Respiratory and Critical Care Medicine 155, no. 2 (1997): 568-76.

Evans, G. W., and E. Kantrowitz. "Socioeconomic Status and Health: The Potential Role of Environmental Risk Exposure." Annual Review of Public Health 23 (2002): 303-31.

Feldman, P. J., and A. Steptoe. "How Neighborhoods and Physical Functioning Are Related: The Roles of Neighborhood Socioeconomic Status, Perceived Neighborhood Strain, and Individual Health Risk Factors." Annals of Behavioral Medicine 27, no. 2 (2004): 91-9.

Garty, B. Z., E. Kosman, E. Ganor, V. Berger, L. Garty, T. Wietzen, Y. Waisman, M. Mimouni, and Y. Waisel. "Emergency Room Visits of Asthmatic Children, Relation to Air Pollution, Weather, and Airborne Allergens." Annals of Allergy, Asthma and Immunology 81, no. 6 (1998): 563-70.

Gehring, U., J. Cyrys, G. Sedlmeir, B. Brunekreef, T. Bellander, P. Fischer, C. P. Bauer, D. Reinhardt, H. E. Wichmann, and J. Heinrich. "Traffic-Related Air Pollution and Respiratory Health During the First 2 Yrs of Life." European Respiration Journal 19, no. 4 (2002): 690-8.

Genereux, M., N. Auger, M. Goneau, and M. Daniel. "Neighborhood Socioeconomic Status, Maternal Education and Adverse Birth Outcomes among Mothers Living near Highways." Journal of Epidemiology and Community Health 62, no. 8 (2008): 695-700.

Heinrich, J., and H. E. Wichmann. "Traffic Related Pollutants in Europe and Their Effect on Allergic Disease." Current Opinions Allergy Clinical Immunology 4 (2004): 341-48.

Hoek, G., Meliefste, K., Brauer, M., van Vliet, P., Brunekreef, B., and Fischer, P. “Risk Assessment of Exposure to Traffic-Related Air Pollution for the Development of Inhalant Allergy, Asthma and Other Chronic Respiratory Conditions in Children (TRAPCA)”. Utrecht: IRAS University, 2001.

Holguin, F

., S. Flores., Z. Ross, M. Cortez M Molina, L. Molina, C. Rincon, M. Jerret, K. Berhane, A. Granados, and I. Romieu “Traffic-related exposures, airway function, inflammation, and respiratory symptoms in children.” European Respiratory Journal, 21, no. 6, (2007): 913-5.

Javaheri, S., A. Storfer-Isser, C. L. Rosen, and S. Redline “Sleep Quality and Elevated Blood Pressure in Adolescents.” Circulation, 118, (2008): 1034-40.

Kakizaki M., K. Inoue, S. Kuriyama, T. Sone, K. Matsuda-Ohmori, N. Nakaya, S. Fukudo, and I. Tsuji. “Sleep duration and the risk of prostate cancer: the Ohsaki Cohort Study.” British Journal of Cancer 99 no. 1 (2008): 176-8.

Leger D. “The cost of sleep-related accidents: a report for the National Commission on Sleep Disorders Research.” Sleep, 17, (1994): 84-93.

Lercher, P. "Environmental noise and health: An integrated research perspective." Environment International 22, no. 1 (1996): 117-129.

Lewis, S.A., J. M. Corden, G. E. Forster, and M. Newlands. “Combined effects of aerobiological pollutants, chemical pollutants and meteorological conditions on asthma admissions and A & E attendances in Derbyshire UK, 1993–96.” Clinical & Experimental Allergy, 30, no. 12 (2000): 1724-32.

Link, B.G. and J.O. Pheland. “McKeown and the idea that social conditions are fundamental causes of disease.” Health, Policy and Ethics, 92 no.5 (2002): 730-732.

Matheson, M., and S. Stansfeld. "Noise pollution: non-auditory effects on health." British Medical Bulletin 68 (2003): 243-257.

Maupin P., and P. Apparicio. “Relationships between Ambrosia artemisiifolia sites and the physical and social environments of Montreal (Canada).” Geoscience and Remote Sensing Symposium , IGARSS 04. Proceedings. International 1 (2004): 238.

Maupin, P., and A. L. Jousselme, “Vagueness, a multifaceted concept - a case study on Ambrosia artemisiifolia predictive cartography.” Geoscience and Remote Sensing Symposium. IGARSS 04 Proceedings. IEEE International 1 (2004): 363.

Mehmet Birhan, Y. Kenan , T. Okan Onur, Y. Ahmet, Y. Oguzhan, B. Gokhan , and T. Izzet “Sleep quality among relatively younger patients with initial diagnosis of hypertension: Dippers versus non-dippers.” Blood Pressure, 16 no. 2 (2008): 101-5.

Morgenstern, V., A. Zutavern, J. Cyrys, I. Brockow, S. Koletzko, U. Krämer, H. Behrendt, O. Herbarth, A. von Berg, C. P. Bauer, H. E. Wichmann, and J. Heinrich, “Diseases, allergic sensitization, and exposure to traffic-related air pollution in children.” American Journal of Respiratory Critical Care Medicine, 177, no. 12, (2004): 1331-7.

Nicolai, T., D. Carr, S. K. Weiland, H. Duhme, O. von Ehrenstein, C Wagner, and E von Mutius. “Urban traffic and pollutant exposure related to respiratory outcomes and atopy in a large sample of children.” European Respiratory Journal 21, no. 6, (2003): 956-63.

Nilsson, L., O. Castor, O. Löfman, A. Magnusson, and N.I.M. Kjellman, “Allergic disease in teenagers in relation to urban or rural residence at various stages of childhood.” Allergy 54, (1999): 716-21.

Muller-Wenk, R. "A method to include in LCA Road Traffic noise and its health effects." International Journal of Life Cycle Assessment 9, no. 2 (2004): 76-85.

Passcher, W., and W. Passcher-Vermeer. "Noise exposure and public health." Environmental Health Perspectives 108 (March 2000): 123-131.

Papadakaki, M., T. Kontogiannis, G. Tzamalouka, C. Darviri, and J. Chliaoutakis. “Exploring the effects of lifestyle, sleep factors and driving behaviors on sleep-related road risk: A study of Greek drivers.” Department Accident Analysis and Prevention, 40, (2008): 2029-36.

Pickett, K. E., and M. Pearl. “Multilevel Analysis of neighborhood outcomes: A Critical Review.” Journal of Epidemiology Community Health 55, (2001): 111-122.

Pilcher J.J., and A. I. Huffcutt. “Effects of sleep deprivation on performance. A meta-analysis.” Sleep, 19, (1996): 318-26.

Puliafito, E., M. Guevara, and C. Puliafito. “Characterization of urban air quality using GIS as a management system.” Instituto para el Estudio del Medio Ambiente (IEMA), Universidad de Mendoza, (2002).

Ross, N. A., S. Tremblay, and K. Graham. “Neighborhood influences on health in Montreal, Canada.” Social Science and Medicine, 59, (2004): 1485-1494.

Rosas, I., H. A. McCartney, R. W. Payne, C. Calderon, J. Lacey, R. Chapela and S. Ruiz-Velazco. “Analysis of the relationships between environmental factors (allergens, air pollution, and weather) and asthma emergency admissions to a hospital in Mexico City.” Allergy, 53, (1998): 394-401.

Smargiassi, A., K. Berrada, I. Fortier, and T. Kosatsky, “Traffic intensity, dwelling value, and hospital admissions for respiratory disease among the elderly in Montreal (Canada): a case-control analysis.” Journal of Epidemiology, Community and Health, 60, (2006): 507-512.

Stansfield, S., M. Haines, and B. Brown. "Noise and health in the urban environment." Review of Environmental Health 15, no. 1-2 (2000): 43-82.

Subramanian, S.V., J. T. Chen, D. H. Rehknopf, P. D. Waterman, and N. Krieger “Comparing Individual and area based socioeconomic measure for the survelliance of health disparities: A multi-level analysis of Massachusetts Births, 1989-1991.” American Journal of Epidemiology, 164, no. 9, (2006):823-834.

Tasali, E., R. Leproult, and K. Spiegel. “Reduced Sleep Duration or Quality: Relationships with insulin resistance and type 2 diabetes.” Progress in Cardiovascular Diseases, 51, no. 5 (2009): 381-391.

Touchette, E., D. Petit, J. R. Séguin, M Boivin, R E Tremblay, and J Y. Montplaisir, “Associations between sleep duration patterns and behavioral/cognitive functioning at school entry.” Sleep 30 no. 9 (2007): 1213-19.

Touchette E., D. Petit, R. E. Tremblay, M. Boivin, B. Falissard, C. Genolini, and J. Y. Montplaisir. “Associations between sleep duration patterns and overweight/obesity at age 6.” Sleep 31 no.11 (2008): 1507-14.

Van Vliet, P., M Knape, J. de Hartog, N. Janssen, H. Harssema, and B. Brunekreef, B. “Motor vehicle exhaust and chronic respiratory symptoms in children living near motorways.” Environmental Respiratory Journal, 74, (1997): 122-32.

Washington State Department of Transportation. "Environment - Air, Acoustics and Energy." (2009),

http://www.wsdot.wa.gov/Environment/Air/TrafficNoise.htm

.

WB&A Market research for the National Sleep Foundation. Sleep in America Poll, (2007).

Zeka, A., S. J. Melly, and J. Schwartz. “The Effect of socioeconomic status and indices of physical environment on reduced birth weight and preterm birth in Eastern Massachusetts.” Environmental Health 7, no. 60, (2008):1-15.