The increasing use of mobile phones in the modern days has led to the question on whether it has possible link with the risk for developing certain diseases, such as cancer. Many studies have been done to find the link between mobile phones and cancer, and many of them have come to inconclusive findings. In response to the years of debate over the health effects of mobile phone use, a US government research program lately conducted a study to find the answer and it had come to a concerning finding.

To get the real picture on the long controversies about whether cell phones may cause cancer or not, some research findings related to the possible link between cell phones and risk for developing cancer and tumors will be elaborated here.

Multiple Studies Found an Alarming Link

A study conducted by National Toxicology Program (NTP) recently conducted an in vivo study on the possible link between tumors and radiofrequency produced by mobile devices in rats, and it concluded that the use of cell phones was related to the incidence of two types of tumor, despite low incidence rate. They are gliomas (which attacks the glial cells of rat’s brain, and schwannomas of the heart.

As reported in Yahoo! News, the study involved exposing more than 2.500 rats to similar type of frequencies and radiation emitted by cell phones. The study, which cost $25 million, involved exposing the rodents to the radiation for nine hours a day, for two years. The study came to conclusion that cancer risk was only found in male rats.

The findings confirmed what the previous study report on the possible link between mobile phones and cancer. In 2011, International Agency for Research on Cancer classified radiation emitted by cell phones as a possible human carcinogen, as a previous research found similar types of tumor in human being. Similarly, the World Health Organization report also noted that radiations from the mobile phones were classified as group B carcinogen.

Controversies on the Link between Mobile Phones and Cancer Remain

The study by National Toxicology Program (NTP) has not made the controversies on whether cell phones may cause cancer or not to an end, since the study was conducted on rodents, instead of human being. The National Institutes of Health (NIH) reported that the study findings were under expert review. The NIH spokesperson reported that previous studies on human beings had come to different findings.

Earlier large-scale population-based studies did not find any convincing evidence on whether the use of mobile devices could increase the risk for developing cancer or not. Moreover, the following findings and expert suggestions contribute to the lingering debate on whether cell phones may cause cancer or not:

• A study, which took 30 years, in Australia, did not find any significant link between mobile device and risk for developing brain cancer in humans. Despite slightly increase of cancer incidence in men since 1993, it remained stable in women. Coffee and some pickled vegetable consumption in men might contribute to the increased risk for cancer.

• The Federal Communications Commission has not made any changes to its policies related to radiofrequency exposure limit, as no expert recommendations as well as evidence had suggested so.

• The Million Women Study, which was conducted on nearly 800.000 women in the United Kingdom, examined the possible link of brain tumor and the use of cell phones for more than 7-year period. The study found no link between brain tumors and several common sub-types of brain tumor and the use of mobile devices. However, the study found a possible link between acoustic neuromas and long-term use of mobile phones.

• The Interphone Study, which was conducted in 13 countries and involved more than 1.000 people who developed neuromas, came to a different conclusion. The study also involved 2.000 peoples without tumors as matched controls. It found no significant link between the use of cell phones and acoustic neuromas, despite a possible increased risk in 10% of people who used mobile devices implausibly.

Behind The Concerns That Cell Phones May Cause Cancer

The concerns that cell phones may cause cancer are not without reasons. There are at least three reasons why people are increasingly concern and on the possible link between cell phone use and risks of cancer and tumors.

• Cell phones do emit radiofrequency energy from antennas. This type of non-ionizing radiation can be absorbed by the tissues nearest to the antenna.

• The number of mobile devices has increased rapidly, particularly during the last fifteen years. As reported by Cellular Telecommunicates and Internet Association, there were more than 327.5 million users of cell phones in the United States, compared to 110 million users in 2000.

• Besides the increasing number of cell phones, there are also increasing number of phone calls, lengths of phone calls, and time of cell phone use. This may be attributable to the increasing use of internet-based facilities, such as browsing, social media networking, downloading, video calling, online shopping, video watching, and many other web-based activities.

Human body absorbs energy of radiofrequency electromagnetic radiation used in telecommunication devices, such as cell phones, radio transmissions, and televisions. It is confirmed that exposure to ionizing radiation, such as x-rays, is related to the increased risk for developing cancer. However, studies have been conducted to find out the possible similar effect of non-ionizing radiation as used in telecommunication devices.

Long debates on the possible link between mobile phones and cancer are the results of the fact that no consistent evidence has been found on the relationship between non-ionizing radiation and risk of cancer. Studies did find a link between heating produced by non-ionizing radiation, as used in microwave ovens, and biological effect. However, heating produced by the use of cell phone (particularly to ear and head areas) is not sufficient to increase the body temperature.

Controversies on whether cell phones may cause cancer and several types of brain tumors or not are still far from the conclusive answers. Some studies, which was conducted in 1970s, did find a slight increase in the incidence of brain tumors during the decade, but there were not cell phones in that era. Many factors might contribute to the findings, including improvement in the diagnostic imaging technology and increased access to medical care, which led the researchers and medical professionals to find more cases than they once were.

Findings from Multiple Studies Are Inconsistent

As mentioned above, findings from the studies that examined the possible link between mobile phones and cancer are inconclusive and inconsistent. All studies done so far have their own limitations that make them unable to end the controversies. Many factors may be responsible for these inconsistencies.

• Limitation of research period. No studies have followed the participants for very long periods of time. Few studies had been conducted for more than 20 years. It may take decades for the cancer-causing exposure to show its effect on human health. This limitation is related to the fact that increasing use of cell phones is remarkable only during the last several years (no more than twenty years). Cell phones were not popular before the mid-1990s.

• Limitation of study design. Most of the studies done so far used case controls. This means that the study findings mostly relied upon the participants’ memories about the past use of cell phones. People with existing cancers or tumors might recall their use of cell phones differently from those without cancers or tumors. This makes the possible link between cancer and radiofrequency exposure hard to interpret. Consequently, many of epidemiological studies did not have adequate data on the total amount of mobile device uses over time.

• Participation bias. Some studies were conducted on people with gliomas, which is known to have short survival time. These tumors have higher death rate, compared to any other types of brain cancer. This makes long-term study unlikely, as many of the participants dropped out before the study period ended. Furthermore, people with brain tumors and cancers are more likely to enroll in study compared to healthy people. As a result, the studies might not have adequate case controls.

• Changing cell phone technology. The cell phone technology and method of usage are constantly changing. In the past, most studies evaluated the effect of radiofrequency radiation on the possible increased risk for developing cancer. In fact, most mobile devices today use digital technology, which operates a lower power level and different frequency. The cellular technology keeps changing. Many modern features may contribute to the decrease of radiofrequency exposure, such as texting, use of wireless headsets, and hands-free technology.

The Bottom Line

Do these mean that controversies on the link between mobile phones and cancer will remain? For now, no one knows for sure whether mobile phones can cause cancer or not. The good news is that some studies are under way to find out the answer. One of them is COSMOS study, which was launched in Europe in March 2010. The study involves more than 290.000 cell phone users and will follow the participants for 20 to 39 years. It seems promising, as the study is designed to minimize the possible bias. Let’s wait and see then…