According to the Environmental Protection Agency, indoor air quality has a
tremendous impact on people's health. Germicidal UV light has been proven
effective and utilized in numerous applications to improve indoor air quality
and therefore indoor environment.
The EPA states that indoor air pollution can be much higher than
the outdoor environment. In order to fight indoor air pollution people who suffer from
asthma or allergies attempt to dust more, keep the
windows closed, clean frequently but the allergy or asthma symptoms
usually still persist. One reason is the presence of airborne germs, their particles and by products - allergens or
asthma triggers in the indoor air. These microbes are considerably big factor
in the indoor air pollution.
The airborne germs adversely affect the
indoor air quality as they are blown
past the furnace or air conditioning filter and circulated throughout the
buildings. Ultraviolet light - UVC
- is recommended for hospitals, laboratories, food processing plants and
other public facilities concerned with the indoor air quality as a health factor. UV
was incorporated in The Facilities Standards for the Public Buildings by the U. S. General Services Administration Office of the
Numerous health studies have shown that germicidal ultraviolet light -
UVC - is very effective against mold, mildew, fungi and
viruses, bacteria and spores by breaking down their DNA or RNA. UV light can play a great role in
secondary allergy prevention especially where airborne allergens are
concerned. It can reduce suffering from allergies. The UV air cleaners help control germs that make asthma worse.
Ultraviolet Germicidal Irradiation - UVGI is the use of short UV
waves, known as UVC, which has been proven to kill or inactivate
tuberculosis in the indoor air. There are two ways in which UV lamps are used
indoor air quality
control - upper-room air and in-duct ultraviolet germicidal irradiation.
Many airborne pathogens can be removed from the indoor air by the use
of germicidal ultraviolet air disinfection systems.
The following UV resources offer detailed information on how modern
technology uses the ultraviolet light in residential and commercial
settings to fight mold and airborne pathogens helping provide healthier
Watch - Mold Analysis Reports
UV against Avian (Bird) Flu
Position Document on Airborne Infectious Diseases
UV helps fight
UV Effective Against Bioterrorism - A Harvard Public
Ultraviolet against bioterrorism /PDF
UV For Biological Protection - FEMA
UV Light fights
UV for control of tuberculosis TB
UVC and IAQ Case Study in a school
UVC and IAQ Case Study in a city hospital
UV in GSA Standards
for the Public Buildings
Articles referencing UV and the Indoor Air Quality
Mold Remediation and Indoor Air
Indoor air pollution
Summary posted by American Air & Water on 4/22/2010
Source: American Friends of Tel Aviv University
Scientists at Tel Aviv University, Israel, have determined that ultraviolet (UV)
light may be a better solution to keeping tap water clean than the chlorine
traditionally used by water treatment facilities. The researchers found that UV
wavelengths at the nanoscale (optimally between 254 and 270 nanometers)
effectively cleaned the water and helped keep membranes in desalination plants
clear of bacterial build-up. According to Anat Lakretz, a doctoral student, "The
best way to control and kill these micro-organisms was to damage their DNA. The
damage that the UV light causes has no known negative effect on the water." The
UV light approach works even better against parasites that aren't killed with
chlorine treatment, such as Giarrdia and Cryptosporidium, two parasites that can
cause severe diarrhea and can lead to death. Children, the elderly and those in
developing nations are particularly vulnerable to these parasites. Lakretz says
"Sewage leakage into water supplies poses a big problem in terms of bacterial
contamination, and is something UV light could remediate." Small amounts of
chlorine would still be needed, but overall this new method would significantly
reduce the amount of carcinogenic by-products from chlorine and make water
treatment more efficient and cost effective.
UVGI Testing Report
|The objective of this project
was to assess microbial levels in air and on surfaces in Ingham
Hospital before and after the installation of a UVGI-HVAC system.
Using bacteria and fungi levels as a standard of effectiveness of
the UVGI-HVAC system, indoor air samples were collected before and
after UV installation and microbial levels were compared. Using
the impingement method viable microorganisms (E. coli, total
bacteria, Staphylococci, MRSA, and fungi) were sampled in the air.
This study also investigated indoor surface contamination because
fomites have been shown to act as reservoirs for spreading
diseases. Samples were collected pre and post UVGI installation.
On both campuses of Ingham Regional Hospital, the UV systems have
decreased all microorganism levels in the post installation tests
in the air and on surfaces.
See UV testing report /PDF/
|Some properly designed, and
well-maintained, UV Germicidal Irradiation installations have proven highly effective,
as in certain hospitals, and some studies performed in schools. CDC
guidelines recommend the use of Ultraviolet Germicidal Irradiation only with the simultaneous
use of HEPA filters and high rates of purge airflow. The
germicidal effects can also be species-dependent.
UV Air Cleaner Guide
|The printable version of the
UV Guide can be downloaded as a PDF file.