Abstract
Objective: Some studies have suggested that residential proximity to high traffic areas is associated with increased risk of childhood cancer, although the epidemiologic evidence to date has been mixed. This study takes advantage of available information on population-based cancer reporting and various spatially assigned indices of traffic in a sufficiently large and heterogeneous area to obtain reasonably stable estimates of risk associations. Methods: The time period 1988–1994 included a total of 7143 newly diagnosed cases of childhood cancer and 46 million child-years of observation in California. Rate ratios, estimated via Poisson regression (with adjustment for age, sex, and race/ethnicity), were computed for estimated traffic level as measured by spatial information on neighborhood vehicle density, road density, and traffic density. Results: Compared to area air monitoring data, traffic density estimates were the most strongly correlated with measures of benzene and 1,3-butadiene. Rate ratios at the 90th percentile of traffic density (neighborhoods with over 320,700 vehicle miles traveled per day per square mile) were 1.08 (95% CI 0.98–1.20) for all cancers in children, 1.15 (95% CI 0.97–1.37) for the leukemias, and 1.14 (95% CI 0.90–1.45) for the gliomas. There was also little or no evidence for rate differences in areas characterized by high vehicle or road density. Conclusion: These data suggest that childhood cancer rates are not higher in high traffic neighborhoods, but future studies which can better refine timing and measures of exposure are needed to more directly address the question of etiologic risks.
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References
California Air Resources Board (2000) 1996 California Toxics Inventory [Web page]. Available at http://www.arb.ca.gov/toxics/ cti/cti.htm (accessed 15 April 2001).
International Agency for Research on Cancer (1982) Evaluation of the Carcinogenic Risk of Chemicals to Humans, 29th edn. Lyon: IARC.
Rinsky R, Smith A, Hornung R, et al. (1987) Benzene and leukaemia: an epidemiological risk assessment. N Engl J Med 316: 1044–1050.
United States Environmental Protection Agency (1999) Integrated Risk Information System (IRIS) [Web page]. Available at http:// www.epa.gov/iris/subst/ (accessed 12 April 1999).
International Agency for Research on Cancer (2000) IARC Monographs Programme on the Evaluation of Carcinogenic Risks to Humans [Web page]. Available at http://monographs.iarc.fr/ (accessed 15 April 2001).
California Air Resources Board (1998) Measuring Concentrations of Selected Air Pollutants Inside California Vehicles. Sacramento, CA: Research Division.
Kinney PL, Aggarwal M, Northridge ME, Janssen NAH, Shepard P (2000) Airborne concentrations of PM2.5 and diesel exhaust particles on Harlem sidewalks: a community-based pilot study. Environ Health Perspect 108: 213–218. 672 P. Reynolds et al.
Dubowsky S, Wallace L, Buckley T (1999) The contribution of traffic to indoor concentrations of polycyclic aromatic hydrocarbons. J Exp Anal Environ Epidemiol 9: 312–321.
Savitz DA, Feingold L (1989) Association of childhood cancer with residential traffic density. Scand J Work Environ Health 15: 360–363.
Nordlinder R, Jarvholm B (1997) Environmental exposure to gasoline and leukemia in children and young adults-an ecology study. Int Arch Occup Environ Health 70: 57–60.
Feychting M, Svensson D, Ahlbom A (1998) Exposure to motor vehicle exhaust and childhood cancer. Scand J Work Environ Health 24: 8–11.
Pearson R, Wachtel H, Ebi K (2000) Distance-weighted traffic density in proximity to a home is a risk factor for leukemia and other childhood cancers. J Air Waste Manag Assoc 50: 175–180.
Harrison RM, Leung P, Somervaille L, Smith R, Gilman E (1999) Analysis of incidence of childhood cancer in the West Midlands of the United Kingdom in relation to proximity to main roads and petrol stations. Occup Environ Med 56: 774–780.
Reynolds P, Elkin E, Scalf R, Von Behren J, Neutra RR (2001) Case-control pilot study of traffic exposures and early childhood leukemia using a geographic information system. Bioelectromagnetics Suppl. 5: S58-S68.
Langholz B, Ebi K, Thomas DC, Peters JM, London SJ (2002) Traffic density and the risk of childhood leukemia in a Los Angeles case-control study. Ann Epidemiol (In press).
Raaschou-Nielsen O, Hertel O, Thomsen BL, Olsen JH (2001) Air pollution from traffic at the residence of children with cancer. Am J Epidemiol 153: 433–443.
Colt JS, Blair A (1998) Parental occupational exposures and risk of childhood cancer. Environ Health Perspect 106: 909–925.
Savitz DA, Chen J (1990) Parental occupation and childhood cancer: review of epidemiologic studies. Environ Health Perspect 88: 325–337.
United States Bureau of the Census (1992) Census of Population and Housing, 1990: Modified Age/Race, Sex and Hispanic Origin (MARS) State and County File [data file]. Washington, DC: US Bureau of the Census.
California Department of Finance (1998) Race/Ethnic Population with Age and Sex Detail, 1970–2040. Sacramento, CA: State of California, Department of Finance.
Environmental Systems Research Institute, Inc. (1994) ArcView, 3.0 [computer program]. Redlands, CA: Environmental Systems Research Institute, Inc.
United States Bureau of the Census (1995) TIGER Line Files [data file]. Washington, DC: US Bureau of the Census.
California Air Resources Board (1999) The 1999 California Almanac of Emissions and Air Quality. Sacramento, CA: California ARB, Planning and Technical Support Division.
Kono K, Ito S (1990) A micro-scale dispersion model for motor vehicle exhaust gas in urban areas-OMG volume-source model. Atmos Environ 24B: 243–251.
Versluis AH (1994) Methodology for predicting vehicle emissions on motorways and their impact on air quality in the Netherlands. Sci Total Environ 146/147: 359–364.
Fraigneau Y, Gonzalez M, Coppalle A (1995) Dispersion and chemical reaction of a pollutant near a motorway. Sci Total Environ 169: 83–91.
Geographic Data Technology (1995) Streets Network [data file]. Lebanon, NH: Geographic Data Technology.
California Department of Transportation (1993) Highway Performance and Monitoring System [data file]. Sacramento, CA: California DOT.
Watson AY, Bates RR, Kennedy D (1988) Air Pollution, the Automobile, and Public Health. Washington, DC: National Academy Press.
California Air Resources Board (1999) California Ambient Air Quality Data 1980–1998 [data file]. Sacramento, CA: California ARB, Air Quality Data Branch.
Snedecor G, Cochran W (1989) Statistical Methods, 8th edn. Ames, IA: Iowa State University Press.
Rothman K, Greenland S (1998) Modern Epidemiology, 2nd edn. Philadelphia, PA: Lippincott-Raven.
Kleinbaum D, Kupper L, Muller K (1988) Applied Regression Analysis and Other Multivariable Methods, 2nd edn. Boston, MA: PWS-Kent.
SAS Institute, Inc. (1998) SAS, 7.00 [computer program]. Cary, NC: SAS Institute.
Stata Corporation (2001) Stata Statistical Software, 7.0 [computer program]. College Station, TX: Stata Corporation.
Nakai S, Nitta H, Maeda K (1995) Respiratory health associated with exposure to automobile exhaust. II. Personal NO2 exposure levels according to distance from the roadside. J Exp Anal Environ Epidemiol 5: 125–136.
Raaschou-Nielsen O, Hertel O, Vignati E, et al. (2000) An air pollution model for use in epidemiological studies: evaluation with measured levels of nitrogen dioxide and benzene. J Exp Anal Environ Epidemiol 10: 4–14.
Raaschou-Nielsen O, Lohse C, Thomsen BL, Skov H, Olsen JH (1997) Ambient air levels and the exposure of children to benzene, toluene and xylenes in Denmark. Environ Res 75: 149–159.
Armstrong B (1987) A simple estimator of minimum detectable relative risk, sample size, or power in cohort studies. Am J Epidemiol 126: 356–358.
Smith AH, Bates MN (1992) Confidence limit analyses should replace power calculations in the interpretation of epidemiologic studies. Epidemiology 3: 449–452.
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Reynolds, P., Von Behren, J., Gunier, R.B. et al. Traffic patterns and childhood cancer incidence rates in California, United States. Cancer Causes Control 13, 665–673 (2002). https://doi.org/10.1023/A:1019579430978
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DOI: https://doi.org/10.1023/A:1019579430978