The modern world has a problem. We are undergoing spontaneous mutations caused by radiation, even at low levels. This radiation can break chromosomes into pieces that reattach randomly and sometimes create genes that didn't previously exist.

Actually, that's happening because of nature.  Deep space cosmic rays have been doing that to everything on earth for as long as the planet has existed. Even organic food.

High-energy radiation is a different beast, of course, and damage to DNA by high energy radiation constitutes the most lethal damage occurring at the cellular level. Very low-energy interactions - with OH radicals, for instance, say researchers at Tata Institute of Fundamental Research - can also induce DNA damage, including double strand breaks. It is known that single strand breaks in the DNA backbone are amenable to repair but most double strand breaks are irreparable. 

The propensity with which slow OH radicals damage DNA depends on their rotational energy: rotationally "hot" OH is more proficient in causing double breaks, according to findings from experiments conducted on DNA in their physiological environment.

Intense femtosecond laser pulses are propagated through water (in which DNA plasmids are suspended), creating plasma channels within water, resulting in generation, in situ, of electrons and OH radicals. It is shown that use of long laser wavelength light (1350 nm and 2200 nm) ensures only OH-induced damage to DNA is accessed.

They say it is noteworthy that industry presently characterizes as "eye-safe" lasers that emit at wavelengths longer than 1300 nm.

But if it is such wavelengths that are proficient at inducing damage to DNA, how safe is "eye-safe" if DNA in the eye can be readily damaged, the scholars ask? 



Source: Tata Institute of Fundamental Research