As the magnetic worm turns

Magnetite reignites mobile phone radiation concerns.

The world’s most famous nematode worm - Caenorhabditis elegans - contains traces of a magnetic iron oxide known as magnetite, report UK scientists. The particles could help explain why these classic animal models, and maybe even humans, are sensitive to electromagnetic radiation from mobile phones.

C. elegans provides some of the most convincing evidence that radiation from mobile phones could have serious biological consequences. When exposed to mobile phone-like electromagnetic fields, these worms produce heat-shock proteins, suggesting they are experiencing some kind of stress. The presence of magnetite in C. elegans may be what is mediating this kind of stress response. This is one of the most plausible mechanisms proposed to explain the potential harmful effects of mobile phones, says Jon Dobson from the University of Keele. The idea is that when exposed to external fields, magnetite particles could concentrate energy and cause local damage within the organism.

The response of C. elegans to a strong magnetic field is consistent with the presence of iron biominerals like magnetite and greigite, note Dobson and his colleagues. Examination of the worms under a transmission electron microscope also reveals electron-dense particles that contain significant amounts of iron and oxygen but no other elements.

Since the human brain also contains magnetite, these results have implications for the ongoing debate over the safety of mobile phones.

’Documentation of biogenic magnetite in C. elegans would be an incredibly important observation,’ says Joe Kirschvink, from the California Institute of Technology in Pasadena, US. However, he is not convinced that the UK team has shown that the nematodes are producing the magnetite. ’The simplest interpretation is that the worms are accumulating iron-rich particles from their nutrient medium,’ he says.

Dobson admits that this possibility cannot be ruled out. ’The result is preliminary at this stage,’ he says. However, he is still confident that further work will confirm their conclusion. ’It’s highly unlikely that the worms would have just ingested this stuff, basically because there’s not enough of it around to account for all they’ve got in their bodies,’ he concludes.

Henry Nicholls