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Science-based cleaning methods that improve IAQ

September 19, 2010
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According to the Environmental Protection Agency (EPA), people spend 90 percent of their time indoors.

The real bite to this statistic comes in another EPA fact: The air inside a building is often two to five times as polluted as the air outside, even in the most industrial and smog-choked cities.

So where does the pollution come from?

If the microscopic world of a building’s indoor environment became visible, the sight would be alarming.

Pollen, dust mites, fungal spores, dander as well as industrial and vehicle emissions brought in from outside mix with chemical pollutants from within, including cleaning supply residue and emissions from new office equipment, furniture and flooring.

Where it all goes
All of these pollutants float in the air, controlled by drafts, the HVAC system and human movement.

Some settle on the carpet, which acts as a dust sink to hold particles in.

Some land on floors and other hard surfaces, where it is consistently stirred back into the air.

And, much of it is inhaled by those inside the building.

On average, each person consumes up to 40 pounds of air each day.

When indoor air is excessively polluted, the result can be anything from headaches, fatigue and shortness of breath to asthma, allergy attacks and respiratory illnesses.

There are also more incremental, insidious costs.

The EPA estimates that poor IAQ can result in lower productivity and missed work days, costing the nation tens of billions of dollars each year in lost productivity and medical care.

The study
Daily cleaning and maintenance can make a significant impact in improving IAQ, if done using optimal equipment and effective, efficient techniques.

One recent study conducted at the University of North Carolina, Chapel Hill, charted the basic elemental differences between two cleaning methods — differences that could dramatically impact occupant health.

The UNC study scientifically measured airborne dust levels, fungal spore counts, bacteria levels and volatile organic compound (VOC) emissions in buildings at the university.

One building was cleaned using Zone Cleaning methods, which had been in place at the university prior to the study.

Another university building was cleaned using a standardized Team Cleaning approach to housekeeping, the ManageMen Operating System 1 (OS1).

This system involves a properly trained and equipped staff, effective equipment and supplies a detailed cleaning plan and schedule as well as efficient, preventative cleaning techniques.

Scientific measures
The study found dramatic results between the two methodologies.

Levels of dust, fungal spores and other allergens in the buildings were significantly reduced after using the (OS1) system.

As the study’s technical advisor, Michael A. Berry, Ph.D., noted in a recently published lecture, The Science of Cleaning: “Your greatest route of exposure is particles in air. Those particles do damage to the lung and can do bad things if highly concentrated. So if you clean the different compartments (the carpet, horizontal shelves, hard floor surfaces), you affect the air quality.”

Over the course of the (OS1) pilot study, Berry said, “We dropped hard floor dust by a factor of two (twice as good) and a factor of four (four times better) in the carpet dust as measured on a particle counter.”
Fungal spore counts were also measured.

“We took a look at fungal spores, associated with dusts,” reported Berry in The Science of Cleaning. “Fungal spores are an indication of asthma attack risks indoors. Our highest fungal spore counts were in the zone building, where 15 percent of our samples were too numerous to count. After (OS1) was put in place, the counts dropped down.”

Overall fungal spore counts were reduced by up to 90 percent.

Bottom line on bacteria
The message is simple: To effectively clean a building, remove the pollutants.

To remove dust, fungal spores and other airborne matter, vacuums are a vital part of the cleaning equation.

Other important measures include: Balancing the HVAC system, checking for leaks that lead to mold and using cleaning chemicals with low VOC emissions.

“A good vacuum will pull out a lot of your fungal spores once you get all the water intrusion,” noted Berry. “Bacteria (are) the same way; (they are) a hard critter to manage, but even there we were able to knock the bacteria levels down.”

A vacuum can either dramatically reduce allergens or it can contribute to the problem.

This depends on the amount of dust and other pollutants the vacuum extracts from carpet or a hard floor as well as what the vacuum’s filtration system retains.

Vacuums to the test
During the (OS1) UNC pilot study, particle counters were used to measure the amount of particulate matter emissions associated with a Green Label backpack vacuum with four-level filtration and the upright vacuums currently in use at the university.

When the Green Label backpack was tested, there were virtually no detectable emissions and the counter read the same as the background “noise,” approximately 35 micrograms per cubic meter of air.

When the upright was tested, the level of emissions shot up to 240 micrograms per cubic meter.

The Green Label vacuuming testing and certification program, started by the Carpet & Rug Institute in 2000, sets the maximum vacuum emission levels at 100 micrograms per cubic meter.

A high amount of microscopic dust being blown from the carpet or hard floors back into the air can be hazardous for a building’s IAQ.

Particles can remain in the air for eight to 12 hours before settling down again.

This pollutant-laden dust will remain in the environment and can be easily inhaled by a cleaning worker and the building’s occupants.

The only way to effectively trap dust in a vacuum is with an advanced, multi-stage filtration system, one that includes a micro filter to capture microscopic dust mites, pollen, skin flakes, dander, mold and bacteria.

A high-quality filtration system can capture and contain 99.9 percent of particles measuring one micron and larger.

A true HEPA filtration system can capture 99.97 percent of particles down to .3 microns in size.

The CRI Green Label program also sets standards for soil removal and carpet appearance retention, meaning the vacuum should be able to pull out soil with high-powered suction without damaging the carpet fibers.

Even with the best equipment, such as a Green Label vacuum, a standardized cleaning system that ensures all areas in a building are consistently vacuumed or dusted is important and should include carpets, hard floors, light fixtures, windowsills, desks and other places dust can settle.

As the UNC study shows, when a building is cleaned, the appearance should improve, along with the health of those who spend a majority of their time inside it.


Jessica Holmes is a freelance writer based in Boise, ID, with a focus on the JanSan and construction industries.

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