Oct 10, 2024

Panasonic Verifies that nanoe™ (Hydroxyl Radicals Contained in Water) Technology Inhibits Hazardous Substances Contained in Haze Caused by Air Pollution in Southeast Asia^*1

Osaka, Japan – Panasonic Corporation (https://www.panasonic.com/global/home.html) (hereinafter referred to as Panasonic) today announced that it has conducted joint research with the Malaysia-Japan International Institute of Technology (MJIIT), under the supervision of Professor Sheikh Ahmad Zaki, verifying that nanoe™ (hydroxyl radicals contained in water) technology inhibits up to 95% of polycyclic aromatic hydrocarbons (PAHs) contained in PM2.5, a component of smoke pollution (haze) that is worsening in Southeast Asia. In addition to the five types of PAHs already verified,*² the inhibitory effects of nanoe™ (hydroxyl radicals contained in water) technology on three types of PAHs have been newly revealed.

99% of the world's population lives in areas that do not meet the World Health Organization's (WHO) air quality guideline levels,*³ and the adverse health effects of air pollution have become a significant issue. In particular, urgent measures are needed to combat haze in Southeast Asian countries. Haze is caused by smoke pollution from large-scale slash-and-burn farming and forest fires in regions like Sumatra Island, and it contains hazardous substances known as PAHs. PAHs are difficult to decompose, making them prone to spread by wind, and it has been reported that they bioaccumulate in crops.*⁴Furthermore, numerous research findings indicate that certain PAHs can elevate the risk and incidence of adverse events, including reduced lung function, worsened asthma, cardiovascular diseases, and cancer.*⁵ Note that this joint verification was intended to examine the effects of nanoe™ on chemical substances that cause these symptoms and does not guarantee effects on the symptoms themselves.

Under the supervision of Professor Sheikh from MJIIT, the Company conducted tests by irradiating nanoe™ (hydroxyl radicals contained in water) particles on three types of PAHs (naphthalene, fluorene, and acenaphthene),*⁶ which account for large proportions in the mass of haze. As a result, inhibitory effects were verified for all three types. Note that these verification results are based on the test conditions described below and do not demonstrate the effectiveness in a real-world environment.

Figure 1 Mass ratios of PAHs contained in haze during a haze warning period*⁶

Table1 Rates of inhibiting PAHs achieved through nanoe™ (hydroxyl radicals contained in water) irradiation*⁷

Panasonic aims to contribute to society by providing safe and secure spaces, and will continue to evolve nanoe™ (hydroxyl radicals contained in water) technology and pursue its future potential.

■Key points of this verification

Aims to verify the inhibitory effects of nanoe™ (hydroxyl radicals contained in water) on the three types of PAHs that account for particularly large mass ratios in haze.

Test conditions

Figure 2 Schematic diagram of the test environment

Verification organization: Malaysia-Japan International Institute of Technology (MJIIT)
Verification subjects: Naphthalene, fluorene, acenaphthene
Verification device: nanoe™ (hydroxyl radicals contained in water) generator
Verification method: Place a petri dish containing the PAHs dissolved in a solvent in a 45 L chamber, and irradiate with nanoe™ (hydroxyl radicals contained in water) from a position 10 cm away from the petri dish for one hour. As a criterion condition for determining the inhibitory effects, prepare another petri dish containing the PAHs dissolved in a solvent, and leave it in the box without nanoe™ (hydroxyl radicals contained in water).
The PAHs were then collected and subjected to gas chromatography/mass spectrometry (GC-MS).
The residual concentrations of the PAHs were calculated from each peak area of the spectrum obtained from the GC-MS measurement.
The rates of PAHs inhibition were determined by comparing two conditions: one exposed to nanoe™ (hydroxyl radicals contained in water) and the other left in the box without nanoe™ (hydroxyl radicals contained in water).*⁷

■Verification results

Figure 3 Rates of PAHs inhibition through exposure to nanoe™ (hydroxyl radicals contained in water)*⁷

The following shows the results of the PAHs inhibition rates*⁷ verified after one hour of exposure to nanoe™ (hydroxyl radicals contained in water).

■Comments of Professor Sheikh Ahmad Zaki from Malaysia-Japan International Institute of Technology^*8

Haze is a serious social issue in Southeast Asia. As human activities, which had slowed down during the COVID-19 pandemic, begin to pick up again, there is a risk that damage will worsen due to increased haze emissions. Haze contains various substances, and PAHs are considered highly hazardous to both humans and the environment. In this verification, we were able to demonstrate the effectiveness of nanoe™ (hydroxyl radicals contained in water) technology against the three types of PAHs that are commonly found in haze. Based on these verification results, nanoe™ (hydroxyl radicals contained in water) technology is anticipated to be a promising solution for enhancing the living environment in Southeast Asia, which is suffered by haze.

■Principle of nanoe™ (hydroxyl radicals contained in water) generation

Figure 4 nanoe™ (hydroxyl radicals contained in water) generator

nanoe™(hydroxyl radicals contained in water), which is approximately 5 to 20 nanometers in size and contains hydroxyl radicals, is generated by cooling the atomizing electrode with a Peltier element, creating water through the condensation of moisture in the air, and applying a high voltage between the atomizing electrode and the counter electrode (Figure 4).

Notes:
*1: The eight types of PAHs include benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, and dibenz[a,h]anthracene, which were previously tested, along with naphthalene, fluorene, and acenaphthene, which were tested this time.
*2: [Press release] "Nanoe" effectively breaks down PM2.5 components and inhibits growth of fungi attached to Yellow Sand (January 16, 2014)
"Nanoe" effectively breaks down PM2.5 components and inhibits growth of fungi attached to Yellow Sand | Appliances | Products & Solutions | Feature Story | Panasonic Newsroom Global https://news.panasonic.com/global/stories/668
*3: Reference: Ambient (outdoor) air pollution. WHO. 2024-09-13
*4: Reference: WHO Regional Office for Europe, "Human health effects of polycyclic aromatic hydrocarbons as ambient air pollutants: report of the Working Group on Polycyclic Aromatic Hydrocarbons of the Joint Task Force on the Health Aspects of Air Pollution.", 2021.
*5: Reference: Nor Azura Sulong et al. "Distribution, sources and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 collected during different monsoon seasons and haze episode in Kuala Lumpur," Chemospher, vol.219, pp. 1-14, 2019.
*6: Reference: Jiraporn Chomanee et al. "Physicochemical and toxicological characteristics of nanoparticles in aerosols in southern Thailand during recent haze episodes in lower southeast Asia," Journal of environmental sciences, vol.94, pp. 72-80, 2020.
*7: Calculated by Panasonic
*8: Panasonic requested the Professor to provide comments on nanoe™ (hydroxyl radicals contained in water), which were posted after editing.

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About Panasonic Corporation

Panasonic Corporation offers products and services for a variety of living environments, ranging from homes to stores to offices and cities. There are five businesses at the core of Panasonic Corporation: Living Appliances and Solutions Company, Heating & Ventilation A/C Company, Cold Chain Solutions Company, Electric Works Company and China and Northeast Asia Company. The operating company reported consolidated net sales of 3,494.4 billion yen for the year ended March 31, 2024. Panasonic Corporation is committed to fulfilling the mission of Life Tech & Ideas: For the wellbeing of people, society and the planet, and embraces the vision of becoming the best partner of your life with human-centric technology and innovation. Learn more about Panasonic: https://www.panasonic.com/global/about/

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