Residential exposure to petrochemicals is associated with an elevated risk of leukemia among adults in their 20s, according to a new report.

Previous studies have linked workplace exposure to petrochemicals with an increased risk of leukemia. By contrast, relatively few studies have looked at the impact on leukemia risk of petrochemical exposure in places where people reside, and the studies that have done so included only crude measures of exposure.

Dr. David C. Christiani, from Harvard School of Public Health in Boston, and colleagues looked at this issue in Kaohsiung, southern Taiwan, an area with four oil refineries. The study, which included 171 patients with leukemia and 410 unaffected ‘control’ subjects, focused on the risk in those aged up to 19 years and those between 20 and 29.

The researchers used geographic information tools to develop a procedure for estimating petrochemical exposure at the individual level, they explain in the American Journal of Epidemiology.

The exposure measurement accounted for a number of factors, including how much people moved around, their length of stay at each residence, distance to petrochemical plants, prevailing wind direction on a monthly basis, and the effect of multiple pollution sources.

Residential exposure to petrochemicals was not linked to leukemia in the younger age group, the team reports. However, in the older group, as the exposure opportunity score increased by one unit, the risk of leukemia rose by 54 percent.

The researchers suggest that future studies consider other sources of indoor or mobile pollution to better understand the carcinogenic effects of petrochemical exposure.

SOURCE: American Journal of Epidemiology, August 1, 2006.