Sharp Corporation, using technology*² developed by Dr. Melvin First, Professor Emeritus of the Harvard School of Public Health and a leading US authority on public health*³, has verified in a test chamber (volume of 40 m³) the effectiveness of Plasmacluster Ion Technology, a proprietary air purification system that eliminates harmful airborne substances by releasing positive and negative ions into the air, in eliminating a serratia bacteria*⁴ (airborne pathogenic bacterium).

Serratia bacteria is a well-known nosocomial pathogen that is present in hospitals and in environments with high humidity such as the sinks and bathrooms of ordinary homes. When people who are in a weakened physical state inhale airborne water droplets which contain this bacteria, it can lead to respiratory infections and diseases such as pneumonia.

Now, tests performed in a chamber having a volume of 40 m³ in a laboratory leveled Bio-Safety Level 3*⁵ to handle airborne microorganisms, virus experiments, and the like, confirm that when serratia bacteria were dispersed in the chamber and the change in concentration measured when Plasmacluster Ions were released into the space, 99% of the bacteria were eliminated in 38 minutes (Figure 1).

Sharp, in cooperation with academic institutions in all parts of the world, has thus far demonstrated that Plasmacluster Ions are effective in eliminating harmful airborne substances such as floating bacteria, fungi, viruses and allergens. Serratia becomes the 27^th such species. Sharp is pushing ahead the technological developments further to contribute to create healthy environment.

In addition, based on the verification results obtained at this time, Sharp is actively working to expand its presence in the global air-conditioning market in North America, Europe, and ASEAN countries under the concept of "Fill every space with Plasmacluster Ions."

Effect of Plasmacluster Ions in eliminating airborne serratia bacteria

Figure 1: Effect of Plasmacluster Ions in eliminating airborne serratia bacteria
(Survival rate is calculated based on average data from three test runs. Natural attenuation is set at 100%.)

Overview of Tests
1. Description of experiment:
Disperse serratia bacteria into the air of a large Bio-Safety Level 3*⁵ chamber having a volume of 40 m³ (Figure 2) and measure the concentration of airborne microbes as Plasmacluster Ions are released into the space and also when no ions are present. Tests were repeated three times to confirm the reproducibility of the data, and the effectiveness of the Plasmacluster Ions in eliminating the bacteria determined.

2. Results:
We were able to verify that releasing Plasmacluster Ions into the space effectively eliminated 99% of airborne serratia bacteria in 38 minutes (Figure 3).

Figure 2: Airborne microorganism test chamber

Figure 3: Results of tests to eliminate airborne serratia bacteria (scale of graph represents bacteria count x 10⁴).

· Serratia bacteria
Serratia bacteria are present in environments inhabited by people, and are especially numerous in places where the humidity is high. When persons in a weakened physical state, such as hospitalized patients, inhale the bacterium, it is known to cause nosocomial (hospital-acquired) infections leading to diseases such as infectious pneumonia and other respiratory illnesses. Because the bacterium may be present in a patient's throat and airways, the infection can be transmitted by airborne droplet nuclei (infection by the bacterium forming particles and dispersing in the air).

Figure 4: Electron microscope photograph of serratia bacteria

· Harvard School of Public Health
Harvard University is a private university founded in 1636 and located in Cambridge, Massachusetts, U.S.A. Seven Presidents of the United States have graduated from Harvard schools and colleges. It is one of the world's leading research institutions and since 1974, nineteen Harvard faculty won Nobel Prize.

The Harvard School of Public Health was founded in 1922 out of the Harvard-MIT School for Health Officers, the first graduate training program in public health in the U.S. The school fosters research aimed at improving public health for people around the world, and is involved in world-class medical research in fields such as HIV/AIDS, SARS, cancer and heart disease.

· Dr. Melvin W. First, ScD, CIH, PE
Professor of Environmental Health Engineering, Emeritus

Dr. Melvin First has more than 50 years of experience as an expert in air cleaning and filtration technology, and has specialized in academic research on living environments and improving public health. At Harvard University, he has conducted research in biotechnology fields using a special microbiological laboratory chamber capable of safely handling a wide range of viruses and bacteria with a view toward infection control. Also, techniques for microbiological evaluation in large spaces is attracting attention because of their potential application to bioterrorism defense technologies.

Overview of Plasmacluster Ion Technology
A plasma discharge generates positive ions (H⁺) and negative ions (O2^-) from water vapor in the air. These ions have the property of clustering around micro-particles, and thus, they surround harmful substances such as airborne mold fungi, viruses and allergens. At that point, a chemical reaction occurs on the cell membrane surface, and the ions are transformed into OH radicals, a powerfully active but unstable material, which robs the harmful substance of a hydrogen atom (H). As a result, the OH radicals inactivate the harmful substances by severing the protein on the cell membrane, opening holes. The OH radicals instantly bond with the removed hydrogen (H), forming water vapor (H2O), and return to the air.

1. Working mechanism to suppress airborne bacteria

2. Working mechanism to suppress airborne viruses

3.Working mechanism to suppress airborne allergens