A long-running litigation over whether wireless phones may cause brain cancer may have been delayed yet again, after an appeals court determined that a different standard of evidence must be met for expert witness testimony in the lawsuits. 

Last week, the District of Columbia Court of Appeals ruled that a new evidentiary standard needs to be used in a lawsuit originally filed in 2001, according to a report in the Wall Street Journal.

The wireless phone brain cancer lawsuit includes more than a dozen claims filed against Motorola, Apple, AT&T Samsung and Verizon.

The appeals court ruling comes after a 2014 decision by the Superior Court of the District of Columbia, which allowed plaintiffs to include evidence from five scientists. The defendants appealed, and the ruling by the appeals court indicates that a different standards of evidence must be used by the trial court, which could exclude some of the current scientists selected by plaintiffs’ to offer testimony on the link between cell phones and brain cancer. However, the ruling also could open the door for new experts to be included in the case.

While some studies have found no links between brain cancer and the use of wireless phones and other mobile devices, a number of others appear to show evidence that there is a connection.

In May 2011, the World Health Organization (WHO) announced that it was classifying radiofrequency electromagnetic fields emitted by wireless phones as a possible carcinogen. Similar to this latest study, a working group of 31 scientists from around the world determined that cell phone emissions appeared to be linked to an increased risk of glioma.

However, a study released a little more than a month later by Danish researchers found no link between cell phones and brain tumors.

In May 2014, French researchers found a link between heavy cell phone use and brain cancer. Cell phone users with the longest cumulative duration of calls, 896 hours of talk time or more, were twice as likely to develop brain tumors than those who talked less.

In November 2014, Swedish researchers reported that people who use mobile phones regularly for more than 25 years have an increased risk of glioma of the brain, similar to the tumors found in the rats. That study found that cell phone radiation exposure was linked to a 30% increased risk of brain tumors overall, but at the 25 year point the risk had grown to 300%. However, even at that level, the overall chance of developing glioma was only 0.016%.

Another study, published in May by the government-funded National Toxicology Program, found that rats exposed to radio frequencies similar to those given off by cell phones had an increased risk of two different types of tumors, including gliomas in the brain.

In 2013, the Federal Communications Commission (FCC) announced that it was reassessing the potential effects of radiation exposure from cell phones and mobile devices. The FCC plans to look at radiation exposure and determine how much is emitted by the devices and how those emissions affect humans.

In the meantime, experts recommend users attempt to reduce their risk by using headsets or speakerphones when possible, holding the phone away from the body, and texting instead of calling as often as possible. Some also recommend only using the phone when it has a strong signal.

Tags: AT&T, Brain Cancer, Cell Phone, Motorola, Samsung, Verizon