National Toxicology Program‘s study should have been done a long time ago, before the cell phones were commercially introduced on the market. This is a typical toxicology study aimed at determining the safety of a radiation-emitting gadget.
NTP study suggests that the cell phone radiation increases carcinogenicity, formation of the brain cancer – glioma. Another animal study, published recently by the group of Alexander Lerchl from Germany, observed that cell phone radiation enhances carcinogenic effects of chemicals.
Furthermore, both above mentioned animal studies had well designed and executed radiation exposure of animals and both well controlled for the temperature of the exposed animals. This means that the effects observed in both animal studies were of non-thermal nature, no matter whether we know or do not know yet the mechanism of it.
This means that recently two large, well designed animal studies found that cell phone radiation is involved in carcinogenesis in animals. Such positive results, carcinogenic effect, suggest that human health might be in some danger. However, the size and the scope of the health risk needs to be further examined and determined by epidemiological studies.
As with every scientific study, there are some questions needing some answers and clarifications:
- researchers used the whole body exposure of animals – this might cause different effects than the localized, head-only exposures that humans are experiencing
- what caused high mortality of control rats
- why cancer was induced only in male but not in female rats
- the carcinogenic effect was apparently observed only in rats but not in mice – this difference/discrepancy needs some clarification
NTP study suggests an increase in the formation of brain cancer – glioma – in male rats. Three sets of the epidemiological case-control studies, European Interphone, Hardell group in Sweden and French CERENAT, have shown an increased risk of developing brain cancer – glioma – in avid, long term users of cell phone (ca. 30 min/day for 10+ years). This similarity between the findings of epidemiological studies and the animal studies – increase in glioma – adds a strength to the conclusions of the NTP study. It also strengthens the calls for the implementation of the Precautionary Principle in the area of cell phones and human health risk. It seems that the human health risk might not only be possible but it might rather be probable, in language of the IARC cell phone radiation could be upgraded from group 2B to group 2A.