THURSDAY, July 28 (HealthDay News) -- Children raised on livestock farms are at significantly greater risk of developing blood cancers -- such as leukemia, multiple myeloma and non-Hodgkin's lymphoma -- later in life, a new study contends.

The researchers pointed out that further studies will be needed before a definitive cause and effect can be established, but they suggested that exposure to particular viruses during childhood may modify the immune system response and result in a higher risk for blood cancer in adulthood.

In conducting the study, published in the July 28 online edition of Occupational and Environmental Medicine, researchers compiled information from 114,000 death certificates for people between 35 and 85 years of age who died between 1998 and 2003 in New Zealand.

The study found that over the five-year period, more than 3,000 deaths were attributed to blood cancers. Moreover, the researchers revealed that growing up on a livestock farm was linked to a higher risk. They noted, however, that people who were raised on farms with crops were not more likely to develop blood cancer.

Overall, the risk of developing a blood cancer was 22 percent higher for those who grew up on a livestock farm than those who did not, according to Andrea 't Mannetje, of the Centre for Public Health Research at Massey University in Wellington, New Zealand, and colleagues.

Being raised on a poultry farm carried the greatest risk, the researchers noted. Those who had spent their childhood living on a poultry farm were three times more likely to develop a blood cancer than others.

On the flip side, growing up on a crop farm came with a nearly 20 percent lower risk of developing blood cancer, the investigators found.

More information

The U.S. Centers for Disease Control and Prevention provides more information on blood cancers.