Most modern textbooks have sections on the proper protections and measures to 
take, although the information may be dated.  See chapter 6 in Volume III of 
the International Tables for X-ray Crystallography.  With the modern equipment 
and regulatory measures in most countries, you really have to work hard to be 
exposed at dangerous levels (which can lead to skin lesions and burns). 
However, you can get yourself exposed if you intentionally circumvent the 
safety measures and interlocks.  In my experience, X-ray exposure in 
crystallography labs is very low and not dangerous.  Our radiation safety 
people find our labs to be very "clean" with respect to scattered radiation 
around the sample compared to medical X-ray labs.  Talk to your institute's 
safety people for advice.

For in-house equipment, you are most at risk of exposure during aligning the 
equipment.  If you talk to the old crystallographers (or their students who are 
now +50 year old), you might hear stories of aligning collimators and cameras 
by the "tingle" on your eye as you look into the beam.  By the time protein 
crystallography came around (50s-60s), phosphors and film were used for 
alignment so the "danger" comes  mostly from scattered radiation and poor 
shielding.  In all the years I have worked with X-rays without protection (I 
only wore a lab coat to prevent film developer from staining my clothes), 
neither I nor my colleagues have ever had X-ray exposures above background as 
determined by film badges and ring badges.  In fact, we once exposed a film 
badge intentionally to see if anyone cared.  We caught hell for doing that.

For synchrotron sources, chances of being exposed as a general user are now nil 
unless you really work hard to subvert the safety measures (which will get you 
kicked out).

Hope this helps,

Michael

****************************************************************
R. Michael Garavito, Ph.D.
Professor of Biochemistry & Molecular Biology
603 Wilson Rd., Rm. 513   
Michigan State University      
East Lansing, MI 48824-1319
Office:  (517) 355-9724     Lab:  (517) 353-9125
FAX:  (517) 353-9334        Email:  [email protected]
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On Jul 12, 2013, at 11:14 AM, diptimayee mishra wrote:

> Dear All,
> Can anyone please tell me regarding the harmful effects of X-ray , we are 
> using for protein crystallography, on human being and what are the 
> precautions we should take.
> 
> Thanks

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