| A Cancer Risk Assessment of Inner-City Teenagers Living in New York City and Los Angeles Sonja N. Sax,1 Deborah H. Bennett,2 Steven N. Chillrud,3 James Ross,3 Patrick L. Kinney,4 and John D. Spengler5 1Gradient Corporation, Cambridge, Massachusetts, USA; 2University of California–Davis, Davis, California, USA; 3Lamont Doherty Earth Observatory, and 4Mailman School of Public Health, Columbia University, New York, New York, USA; 5Harvard School of Public Health, Boston, Massachusetts, USA Abstract
Background: The Toxics Exposure Assessment Columbia–Harvard (TEACH) project assessed exposures and cancer risks from urban air pollutants in a population of high school teenagers in New York City (NYC) and Los Angeles (LA) . Forty-six high school students participated in NYC and 41 in LA, most in two seasons in 1999 and 2000, respectively. Methods: Personal, indoor home, and outdoor home 48-hr samples of volatile organic compounds (VOCs) , aldehydes, particulate matter with aerodynamic diameter ≤ 2.5 µm, and particle-bound elements were collected. Individual cancer risks for 13 VOCs and 6 particle-bound elements were calculated from personal concentrations and published cancer unit risks. Results: The median cumulative risk from personal VOC exposures for this sample of NYC high school students was 666 per million and was greater than the risks from ambient exposures by a factor of about 5. In the LA sample, median cancer risks from VOC personal exposures were 486 per million, about a factor of 4 greater than ambient exposure risks. The VOCs with the highest cancer risk included 1,4-dichlorobenzene, formaldehyde, chloroform, acetaldehyde, and benzene. Of these, benzene had the greatest contributions from outdoor sources. All others had high contributions from indoor sources. The cumulative risks from personal exposures to the elements were an order of magnitude lower than cancer risks from VOC exposures. Conclusions: Most VOCs had median upper-bound lifetime cancer risks that exceeded the U.S. Environmental Protection Agency (EPA) benchmark of 1  10–6 and were generally greater than U.S. EPA modeled estimates, more so for compounds with predominant indoor sources. Chromium, nickel, and arsenic had median personal cancer risks above the U.S. EPA benchmark with exposures largely from outdoors and other microenvironments. The U.S. EPA–modeled concentrations tended to overestimate personal cancer risks for beryllium and chromium but underestimate risks for nickel and arsenic. Key words: aldehydes, cancer risk assessment, metals, personal exposures, VOCs. Environ Health Perspect 114: 1558–1566 (2006) . doi:10.1289/ehp.8507 available via http://dx.doi.org/ [Online 15 June 2006]
Address correspondence to S. Sax, Gradient Corporation, 20 University Rd., Cambridge, MA 02138 USA. Telephone: (617) 395-5530. Fax: (617) 395-5001. E-mail: ssax@gradientcorp.com We extend special thanks to D. Pederson, D. Johnson, M. Aggarwal, S. Ratnam, H. Parise, J. Vallarino, A. Chemor, B. LaBrecque, and S. Forsberg. We are very grateful to the teachers and the schools and especially to the study participants. The study was supported by the Mickey Leland National Urban Air Toxics Research Center (NUATRC-96-01B) , the Columbia Center for Environmental Health in Northern Manhattan [National Institute of Environmental Health Sciences (NIEHS) ES09089], the Columbia Center for Children's Environmental Health (NIEHS ES09600 and U.S. Environmental Protection Agency R827027) , Harvard NIEHS center grant ES000002, and the Akira Yamaguchi endowment fund at the Harvard School of Public Health. The authors declare they have no competing financial interests. Received 15 July 2005 ; accepted 15 June 2006.
Correction In Table 2, for VOCs, values in the rows for MTBE and cumulative risk are incorrect in the original manuscript published online ; they have been corrected here. In Table 3, some of the values under NHAPS have been changed.
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