Q:

I am trying to find out if UV disinfection scanner wands are as effective in killing dust mites as the companies that make them claim and non harmful. Any supporting research would be helpful.

A:

Thank you for your recent inquiry.

Although the Internet is replete with commercial claims for an effect of ultraviolet scanner wands on dust mites, I could find little information in the academic literature confirming the effect of ultraviolet light on dust mites, the exception being an abstract (copied below) from The Journal of Allergy and Clinical Immunology.  

The lead author of this abstract is Dr. Glen  Needham. I have written Dr. Needham to see if there is any further information of which he is aware in this regard. I do not know Dr. Needham personally, and therefore I do not know that we will receive a response, but if we do I will forward his response to you as soon as it arrives. In the meantime, the only information we can offer you of which I am aware is contained within the single abstract copied below. 

Thank you again for your inquiry.  

Abstract:
112 Ultraviolet C Exposure is Fatal to American House Dust Mite Eggs
J ALLERGY CLIN IMMUNOLVol. 117, Issue 2, Page S28, FEBRUARY 2006
G. Needham1, C. Begg2, S. Buchanan3; 1Entomology, The Ohio State University, Columbus, OH, 2Materials Science Engineering, The Ohio State University, Columbus, OH, 3Molecular, Cellular and Developmental Biology, The Ohio State University, Columbus, OH.
Rationale: Ultraviolet C exposure is lethal to an array of organisms by damaging their nucleic acids (DNA and RNA). This non-chemical tactic has been assumed to kill house dust mites (HDM). We tested two exposure times against newly laid Dermatophagoides farinae eggs.
Methods: American HDM eggs were exposed to UV-C for either 5 or 15 seconds at less than 2 cm distance, and hatchability was monitored for 10 days. Specimens were confined in a 24-well titer plate at 70% RH and 27C and compared to untreated controls.
Results: None of the UV-C exposed eggs (23@5 secs; 18@15 secs) hatched while 26 of 27 control eggs hatched into viable larvae. Scanning electron micrographs show that many of the eggs collapsed by 8 days and no larval mites escaped the eggs. Eggs that failed to hatch showed little or no differentiation compared to controls when sub-illuminated using lightlevel microscopy.
Conclusions: UV-C has potential to break the life cycle of HDM by killing the embryonic stage thus stopping the production of allergens. Further susceptibility tests are being conducted with shorter exposure times and against the other life stages.
Funding: UviaClean, Inc.

Sincerely,
Phil Lieberman, M.D.

We have received a response from Dr. Glen Needham, which is copied below. Thank you again for your inquiry and we hope this response is helpful to you.

Sincerely,
Phil Lieberman, M.D.

Response from Dr. Glen Needham:
We did some laboratory testing of the UVC several years back and found the eggs and early instars susceptible to exposure. Efforts to secure funding for field trials from industry were not secured so we only stand behind our laboratory claims. We did work with folks in the OSU College of Public Health on the impact of UVC on surface microbes (attached). That work was published and showed a significant reduction of these organisms as a result of UVC treatment. I understand that Oreck-Halo has been criticized for unsubstantiated health claims (various air filters and UVC). As for risk associated with use, my understanding is that the eyes are the most sensitive to exposure so we used face shields in the laboratory. The vacuum units have a sensory feature that turns the bulb off when it is tipped at a slight angle, and it goes off when the finger trigger is released.

I hope this helps.
Glen Needham, Ph.D.
Associate Professor
Acarology and Entomology
The Ohio State University

AAAAI - American Academy of Allergy Asthma & Immunology