Exposure to Air Pollution During Pregnancy Linked to Increased Incidence of Specific Pediatric Cancers
- Exposure during pregnancy was associated with an increased incidence of three cancers.
- The highest increases were found for retinoblastoma and germ cell tumors.
- Findings require replication in other large studies.
WASHINGTON, D.C. — Increased exposure to traffic-related air pollution during pregnancy was associated with a higher incidence of acute lymphoblastic leukemia and two rare childhood cancers, according to data presented at the AACR Annual Meeting 2013, held in Washington, D.C., April 6-10.
“The main reason for undertaking this study was that we know much more about the causes of adult cancers than we do of the causes of childhood cancers,” said Julia Heck, Ph.D., M.P.H., assistant researcher in the Department of Epidemiology at the University of California, Los Angeles School of Public Health. “We studied pregnancy exposures because the fetus is likely to be more vulnerable to environmental factors during that time, and we also know that certain childhood cancers originate in utero.”
Heck and her colleagues identified 3,590 children from the California Cancer Registry born between 1998 and 2007 who could be linked to a California birth certificate. Children were five years of age or younger at diagnosis. Researchers selected controls at random from 80,224 children listed on California birth rolls. They used the California Line Source Dispersion Modeling Version 4 (CALINE4) to generate estimates of local traffic exposure at the mother’s home during each trimester of pregnancy and during the child’s first year of life. Estimates were based on local traffic emissions of gasoline vehicles and diesel trucks within a 1,500-meter radius buffer and included traffic volumes, roadway geometry, vehicle emission rates and meteorology.
Each interquartile range increase in exposure to traffic-related pollution was associated with an increased risk for developing acute lymphoblastic leukemia (4 percent), retinoblastoma (14 percent for all cases of the disease; 11 percent for retinoblastoma affecting just one eye and 19 percent for retinoblastoma affecting both eyes) and germ cell tumors (17 percent).
Because CALINE4 estimates were highly correlated across trimesters and during the first year of life, the researchers were not able to determine the most important period in terms of exposure.
“This is the first study that’s ever been reported on air pollution as it relates to rarer pediatric cancers, so it needs to be replicated in other states or in other countries,” Heck said. “It would be interesting to determine if there are specific pollutants like benzene or polycyclic aromatic hydrocarbons that are driving these associations.”
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About the American Association for Cancer Research
Founded in 1907, the American Association for Cancer Research (AACR) is the world’s first and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 34,000 laboratory, translational and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 17,000 attendees. In addition, the AACR publishes eight peer-reviewed scientific journals and a magazine for cancer survivors, patients and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the scientific partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration and scientific oversight of team science and individual grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit www.AACR.org.
In Washington, D.C.,
April 6-10, 2013: