University Studies UV Dosage For Anthrax

VALENCIA, CA — A recent study has confirmed that UV light alone is insufficient to disinfect anthrax spores. However, with the correct exposure and proper filtration, UV products can be effective within the hvac system.

Ultraviolet Devices, Inc. (UVDI), announced initial results from its joint research with Pennsylvania State University into the disinfection of Bacillus anthracis spores with ultraviolet C-band (UVC) technology.

Researchers at Pennsylvania State University have identified what they believe to be the most appropriate rate constant for killing Bacillus anthracis using ultraviolet germicidal irradiation (UVGI).

The company explained that with Bacillus anthracis, it is important to differentiate between the vegetive and spore forms. Spore forms are most likely to be used for bioterrorism, the company said, “and are much more robust and difficult to disable with most disinfectants, including ultraviolet light.”

After analyzing the results of three published studies (Sharp 1939, Knudson 1986, and Dietz 1980), as well as prior work completed at Pennsylvania State University relating to airborne pathogens, UVDI’s previous position stating that it is necessary to provide high dosages of UV to “kill” Bacillus anthracis, was confirmed.

Data from the 1986 Knudson study were analyzed and charted. From this, the microorganism’s sensitivity (“rate constant”) to UV light was calculated.

Results indicated that the dose required for 90% disinfection could be as high as 74,000 microwatt seconds/cu cm, or 220,000 microwatt seconds/cu cm for 99.9% disinfection. UVDI explained that “This organism, in spore form, would require about 50 times the UV dose required to disinfect smallpox, tuberculosis, and legionella. It is even more robust than the Aspergillis Niger spore that is considered one of the toughest airborne pathogens.”

According to David Witham, vice president-Technology at UVDI, “This leads us to conclude that control of anthrax by UV alone is not practical.” However, he went on to point out that “due to its relatively large size, about 1.2 microns in its most lethal single-cell size, it can be effectively filtered. ... Once captured on a filter, it can be readily disinfected with UV light.”

Other pathogens, such as smallpox, can be readily handled by UV alone, but may be more difficult to filter, he added. Solutions with the proper UV dosage and filter efficiency can be tailored to most hvac systems.

Publication date: 01/01/2002

Did you enjoy this article? Click here to subscribe to The NEWS Magazine

Recent Articles by James Siegel

You must login or register in order to post a comment.



Image Galleries

2014 World Energy Engineering Congress

Scenes from the 2014 World Energy Engineering Congress in Washington, D.C.


NEWSMakers: Howard Weiss
Howard Weiss, executive vice president, HVAC Excellence stopped by The NEWS’ booth at the AHR Expo to discuss HVAC Excellence’s upcoming conference, networking opportunities at large expo’s, and much more. Posted on Feb. 27.
More Podcasts


NEWS 03-02-15 cover

2015 March 2

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

HVAC Trends

The NEWS regularly reports on HVAC industry trends in our weekly issues. What trends do you see?
View Results Poll Archive


2015 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research


Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.


Magazine image
Register today for complete access to Get full access to the latest features, Extra Edition, and more.


facebook icontwitter iconyoutube iconLinkedIn i con