Do air purifiers, UV lamps work vs COVID-19? Doctors explain
MANILA, Philippines — With talks of Cebu requiring public utility drivers and conductors to wear a personal air purifier at all times or they will be fined, the question about air purifiers being effective in reducing COVID-19 transmission arises.
Department of Health (DOH) Undersecretary Rosario Vergeire yesterday said that DOH does not recommend the use of wearable air purifiers, citing lack of evidence against the claim. She also said that it fosters a false sense of security leading to complacency in observing strict health safety protocols in place.
A doctor of pulmonology at the Makati Medical Center, meanwhile, weighed in on its effectiveness.
Dr. Gregorio Ocampo of Makati Med's Pulmonary Medicine section reaffirmed what the DOH said about the lack of scientific evidence that these personal devices are effective against viruses since they don’t have a reliable filter.
“As far as the medical and scientific community knows, it’s much better to get rid of viruses from the air is through air purifiers with HEPA filters, which these necklaces don’t have,” he said.
He noted, however, that air purifiers have been widely used before this global health crisis, as these have been proven to help alleviate allergic reactions and asthma symptoms.
“As for preventing the spread of COVID-19, it’s best to get air purifiers with HEPA or high-efficiency particulate air filters since it can capture particles smaller than SARS-CoV-2 (the virus that causes COVID-19), which can be transmitted in small droplets that may linger in the air for hours,” he explained.
The size of the room where a unit of an air purifier must be taken into consideration. He also stressed to be cautious of units that produce ozone.
“Be careful of air purifiers that may produce ozone, which can damage the lungs when inhaled. It can even make asthma worse and can cause coughing, throat irritation, shortness of breath, and chest pain even in low amounts,” Dr. Ocampo explained.
Apart from air purifiers and its wearable versions currently being sold in the market, ultraviolet (UV) lamps have also seen rise in popularity among those who want to keep their homes away from the virus.
Dr. Joseph Buensalido of Makati Med's Infectious Diseases section explained that UV light has been used against pathogens for decades, and some recent studies reported that it can also inactivate SARS-CoV-2.
“But to kill viruses and bacteria using UV light, you should use the right kind as there are three types of UV light—UVA, UVB, and UVC. With the shortest wavelength and the highest energy, UVC is also called as germicidal UV as it can inactivate and kill microorganisms,” he added.
He explained that UVC damages the DNA and RNA of pathogens and thus stops them from replicating.
The doctor stressed that harnessing UVC’s disinfecting capabilities requires emitting the right dosage, which can be damaging to human cells. Even brief exposure to UVC can cause skin burns and eye injuries.
“That is why only a trained professional should be allowed to use it within a controlled environment such as hospitals and industrial spaces,” Dr. Buensalido said. “UVC lamps that are marketed for home use may or may not be effective. However, there isn’t enough evidence to use it outside of a clinic or a hospital setting, particularly because it’s misuse may be harmful or produce long-term adverse effects on people’s health.”
Dr. Buensalido reminded consumers that products like UVC lamps and air purifiers should only be part of a multi-faceted approach in fighting the virus.
“Whether you have these devices at home or choose not to get them, nothing beats following minimum standard health protocols such as wearing face masks, frequent washing of hands, observing physical distancing especially in confined spaces, opening windows for improving air flow, and avoiding sick people,” he said. “And these won’t even cost you thousands of pesos.”
