The Nuclear Regulatory Commission is considering an epidemiological study on the affect living near nuclear power plants has on cancer rates, particularly in the case of childhood leukemia, the Los Angeles Times reports.

The San Onofre Nuclear Generating Station was chosen as a representative of one of several different nuclear plant designs that would be covered. It’s the only plant included in the study west of the Mississippi.

The last time such a study was done was 1990, and scientists have relied on its results for the last two decades, though technological advances and improved access to data could provide significantly different results. A 2008 study from Germany, for example, found an increased leukemia rate among children living near nuclear plants there. A French study released this year reached similar conclusions.

The scope of the study being considered by the Commission includes 2.4 million people living within 30 miles of San Onofre, which has been in a state of emergency shutdown since late January.

Scientists have identified a number of challenges in completing the study, the Times notes. A varying amount of reliable data is available on actual radiation released at different plants that would be studied, and due to a large number of people moving into and out of the study zones it could prove difficult to determine where one was living and how long when that person contracted cancer. Smoking and alcohol use, along with working in hazardous conditions, could also mar study results.