SHARECOMMENTMORE

WASHINGTON, D.C. (WUSA9) -- Pregnant women may have one more thing to keep in mind while carrying a child. Surprisingly, it's the air.

Increased exposure to air pollution during pregnancy has been linked to an increased occurrence of three rare pediatric cancers, according to data presented at the American Association for Cancer ResearchAnnual Meeting 2013 held in Washington D.C. this week.

The highest increased risk was found for acute lymphoblastic leukemia (a blood cancer), retinoblastoma (a tumor on the eye) and germ cell tumors (sperm or egg cells that travel to other parts of the body).

"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.

Dr. Heck says this is the first research to report a link between air pollution and rare pediatric cancers.

The study followed children from the California Cancer Registry. All children were under five years old at the time of their diagnosis.

In order to measure air pollution, researchers estimated the amount of local traffic exposure from the mother's home. Each trimester was monitored, as well as the child for one year. However, the study could not determine which trimester the child was most affected.

As exposure to traffic-related pollution increased, the risk of developing acute lymphoblastic leukemia increased by four percent, retinoblastoma in both eyes by 19 percent and germ cell tumors by 17 percent.