Effectiveness of UV-C equipped vacuum at reducing culturable surface-bound microorganisms on carpets

Eric A Lutz, Smita Sharma, Bruce Casto, Glen Needham, Timothy J. Buckley

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Carpets are both sinks and sources for exposure to chemicals, allergens, and microbes and consequently influence health, including asthma, allergies, and infectious diseases. Asthmatics, children, and the immune-compromised are particularly vulnerable to health risks resulting from exposure to carpet contaminants. To address this risk, a commercial upright vacuum cleaner with an ultraviolet germicidal lamp (λ=253.7 nm, UVC) has been developed for residential and commercial uses. However, its effectiveness in reducing microbial load on real-world carpets has not been previously demonstrated. Accordingly, the purpose of the current study was to evaluate the effectiveness of a UVC-equipped vacuum in reducing the carpet surface-bound microbial load. This was accomplished by comparing the carpet microbial surface load from pre- to post-treatment of 9 ft2 in-use carpet sections under three treatment scenarios: 1) UVC alone (UV), 2) the beater-bar plus vacuum (BB+Vac), or 3) a combination of all three (COMB). Each treatment was two minutes in duration. Microbial surface loads were measured by pressing contact plates containing Sabourauds Dextrose agar onto the carpet surface. In-use carpets from three locations were tested in place. The treatment effect was evaluated at two levels. First, we considered the mean reduction in CFU from pre- to post-treatment for each 9 ft2 carpet grid (n = 4 for each treatment). The second level considered each 1 ft2 section using a paired analysis (n = 40 to 49 for each treatment). A total of 125 pre/post-sample pairs were collected across the three treatments. Results showed that all three treatments were associated with a reduction in carpet microbial load (p < 0.0001). The COMB yielded the largest reduction of 13 CFU/plate (87% reduction) and was approximately the sum of the individual effects of either UVC (6.6 CFU/plate, 60% reduction, p = 0.009) or BB+Vac (7.3 CFU/plate, 78% reduction, p < 0.0001). We therefore conclude that a UVC-equipped vacuum approximately doubles the unit's effectiveness in reducing surface-bound microbial load, thereby holding promise as a means for decreasing indoor infectious disease risk.

Original languageEnglish (US)
Pages (from-to)9451-9455
Number of pages5
JournalEnvironmental Science and Technology
Volume44
Issue number24
DOIs
StatePublished - Dec 15 2010
Externally publishedYes

Fingerprint

Microorganisms
microorganism
Vacuum
infectious disease
Vacuum cleaners
Allergies
Ultraviolet lamps
allergy
Health risks
asthma
agar
Allergens
health risk
Agar
Health
Impurities
Glucose
pollutant
post-treatment
exposure

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

Cite this

Effectiveness of UV-C equipped vacuum at reducing culturable surface-bound microorganisms on carpets. / Lutz, Eric A; Sharma, Smita; Casto, Bruce; Needham, Glen; Buckley, Timothy J.

In: Environmental Science and Technology, Vol. 44, No. 24, 15.12.2010, p. 9451-9455.

Research output: Contribution to journalArticle

Lutz, Eric A ; Sharma, Smita ; Casto, Bruce ; Needham, Glen ; Buckley, Timothy J. / Effectiveness of UV-C equipped vacuum at reducing culturable surface-bound microorganisms on carpets. In: Environmental Science and Technology. 2010 ; Vol. 44, No. 24. pp. 9451-9455.
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