DNA can be damaged by very low-energy radiation: How safe are 'eye-safe' lasers?

March 14th, 2014
That energetic particles damage DNA is not surprising. It is now appears that very low-energy OH radicals also damage DNA, with a propensity that depends on how vigorously OH rotates: rotationally 'hot' OH induce irreparable double breaks. These findings utilize OH formed in plasma created when intense IR femtosecond laser pulses propagate in water containing DNA. Industry characterizes as 'eye-safe' IR lasers. With such wavelengths being proficient at inducing DNA damage, how safe is 'eye-safe'?

Damage to DNA by high energy radiation constitutes the most lethal damage occurring at the cellular level. Surprisingly, very low-energy interactions - with OH radicals, for instance - 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. These novel findings are from experiments conducted on DNA in a 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. It is noteworthy that industry presently characterizes as "eye-safe" lasers that emit at wavelengths longer than 1300 nm.

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

Provided by Tata Institute of Fundamental Research

This Phys.org Science News Wire page contains a press release issued by an organization mentioned above and is provided to you “as is” with little or no review from Phys.Org staff.

More news stories

NASA rocket has six minutes to study solar heating

(Phys.org) —On Sept. 30, 2014, a sounding rocket will fly up into the sky – past Earth's atmosphere that obscures certain wavelengths of light from the sun—for a 15-minute journey to study what heats ...

Study clues to aging bone loss

In Canada, bone fractures due to osteoporosis affect one in three women and one in five men over their lifetimes, costing the health care system more than $2.3 billion a year.

Aspirin may lower the risk for aggressive prostate cancer

Use of aspirin and/or other non-steroidal anti-inflammatory drugs (NSAIDs) was associated with a reduced risk for aggressive prostate cancer in men who had elevated prostate specific antigen (PSA) and a negative biopsy prior ...

NASA support key to glacier mapping efforts

Thanks in part to support from NASA and the National Science Foundation, scientists have produced the first-ever detailed maps of bedrock beneath glaciers in Greenland and Antarctica. This new data will help ...

Breakthrough could prevent hip implant replacement

Hip implants rely on the normal functioning of bone cells to achieve fixation of the implant with the bone. However, small metal particles released from hip implants, due to friction between the moving surfaces, ...