According to California researchers, exposure to air pollution during pregnancy may lead to childhood cancers.
Researchers from the University of California, Los Angeles School of Public Health collected data on kids who were diagnosed with cancer before they reached the age of 6. Cancer risk was estimated using a statistical analysis known as unconditional logistic regression.
The study revealed that there are greater chances of three types of rare cancers in children who were exposed to traffic pollution when they were in the womb - acute lymphoblastic leukemia (white blood cell cancer), cancers of the testicles, ovaries and other organs and retinoblastoma (eye cancer).
"This finding is an association, because nothing is proven yet," lead researcher, Julia Heck, an assistant researcher in the department of epidemiology, UCLA's Fielding School of Public Health, said.
However, the results hint that traffic pollution is responsible for childhood cancers, Heck added. "Since this was the first study to report risks for these [uncommon childhood] cancers, these findings need to be confirmed in other studies," she said.
According to California Air Resources, the city has polluted air. Heck explained that certain cancers develop when the baby is in the womb.
However, another expert said that women shouldn't worry about their baby's risk for cancer based on the research.
"There has been an association between air pollution and other diseases," said Dr. Rubin Cohen, director of the Adult Cystic Fibrosis and Bronchiectasis Center at the Long Island Jewish Medical Center in New Hyde Park, New York. "We know that pollution causes asthma, and that is probably more real than the cancer issue."
Heck and the colleagues collected data of 3,600 children below 6 years of age and who were born between 1998 and 2007. The researchers evaluated the data with a similar number of healthy children.
The researchers found that exposure to gas and diesel engines as well as traffic volume, emission rates and weather lead to cancer.
"In terms of the risk, greater exposure was associated with a 5 percent increase in [acute lymphoblastic leukemia] cancers, an 11 percent increase in eye cancer and a 15 percent increase in testicle, ovary and other organ tumors," Heck informed.
The researchers were not able to determine any particular period in pregnancy that is vulnerable to high exposure to pollutants as air pollution was found to be pretty consistent in the study factors.
