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WHO air quality ratings in the U.S.

Ever wonder just how healthy, or unhealthy, the air is in your neck of the woods? Recent WHO ratings can tell you. Air quality, of course, has been linked to a host of ailments, including heart disease and upper respiratory illnesses. Understanding how bad it is where you live can be vital information.


That’s why you might want to take a look at recent ratings from the WHO, or World Health Organization, the United Nations’ agency focused on international public health. It came out with updated research measuring the annual mean concentrations of particulate matter, tiny particles emitted from such sources as cars and power plants, in cities around the world.


The dirtiest five

What were the areas with the worst air quality in the U.S.? The top five, with the highest levels of particulate pollution of less than 10 micrometers in diameter, are mostly in California. Hawaii also makes an appearance:


1. Bakersfield, California

2. Visalia/Porterville, California

3. Ontario, California

4. Hawaiian Ocean View, Hawaii

5. Hanford/Corcoran, California (Tied with Hawaiian Ocean View)


Interestingly, these findings match with measurements determined by the American Lung Association (ALA), using the annual average particle pollution in cities across the U.S.


One noteworthy difference: According to the ALA, Los Angeles, along with the cluster of San Jose/San Francisco/Oakland, California, are among the most polluted in the country. The WHO, for comparison, finds these areas to have high levels of particle pollution, but not the worst. If you’re wondering where the cleanest air can be found in the U.S., the WHO’s findings include Sinclair, Wyoming and Wasilla, Alaska.


Cleaning the air

No matter where you live, there are steps you can take to help improve the air quality inside your home. If you’re in a particularly polluted area, keep your windows closed and remove your shoes when you enter your home, so you don’t unwittingly introduce particles into the air. Also, vacuum and dust regularly. Finally, consider using a smart air purifier with a HEPA filter, like Coway Airmega, that can eliminate up to 99.97 percent of harmful particulate matter from the air.


1Coway air purifiers have been proven to trap dust, pollen, dander, viruses and bacteria in the air based on KCL (Korea Conformity Laboratories) testing.They have been tested in a 30㎥ size chamber according to the Korea Air Cleaning Association standard (SPS-KACA 002-132:2022 Modified) to measure the 0.01㎛ size of particle removal rate. It was tested on maximum airflow speed in normal room temperature and humidity conditions. The performance may vary in the actual living environment of customers.
→ Tested with Airmega Aim, 100, 150, 160, AP-1216L, AP-1512HH, AP-1512HHS, 200M, Icon, IconS, 230, 240, 250, 250 Art, 250S, 300, 300S, 400, 400S, ProX

299.97% of viruses, bacteria, fungi and pollen were verified to be removed from the air for Coway air purifiers which have Green True HEPA™ filter applied based on the Japan Food Research Laboratories(JFRL) testing according to JEM 1467 standard.
→ Tested with Coway Airmega AP-1512HH, AP-1512HHS, 250, 250 Art, 250S, 300, 300S, 400, 400S
→ All tested by JFRL and received above result within below time.

All tested by JFRL and received above result within below time.

- Virus: Tested with Escherichia coli phage ΦX174 NBRC 103405, 60 minutes
- Bacteria: Tested with Staphylococcus epidermidis NBRC 12993, 60 minutes
- Fungi/Mold: Tested with Penicillium citrinum NBRC 6352, 60 minutes
- Pollen: Tested with Cedar Pollen extract, 60 minutes

3Aerosol test conducted in a Biosafety level 3 laboratory with two Coway air purifier models, Coway Airmega 250 and 400 for removal of SARS-CoV-2 Aerosol by US based MRI Global, a not-for-profit laboratory and partner of US Department of Defense. The test was conducted in a 13.1ft3 chamber. Virus was aerosolized for 15 minutes and the product was turned on high for 2 minutes. Result showed each product effectively removed over 99.98% of the SARS-CoV-2 in 2 minutes. This is a result from a laboratory experiment condition and result may vary in different conditions. This result does not imply it kills SARS-CoV-2 or prevents the transmission of Covid-19. Coway Airmega 250S and 400S are identical to the tested models and has equal performance with an additional mobile connectivity function.

4The concentration of ammonia, acetaldehyde and acetic acid were proven to be removed within 30 minutes by FCG Research Institute, Inc. Human Life Science Lab. It is not a demonstration result in the actual use space. Not all odors and gases may be supported. → Tested with Coway Airmega 150, 160, AP-1512HH, AP-1512HHS, 400, 400S

5The coverage area of the air purifier is based on an area where the air cleaner can make two air changes per hour (ACPH). An air change per hour translates to how many times an air purifier can clean an area, assuming the height of a ceiling to be 8 ft, in one hour. Therefore ** means two air changes per hour means that the cleaner can clean the area once every 30 minutes and * means air changes per hour means that the air purifier can clean the area once every 60 minutes.

10Terms and conditions apply. Discounts, including promotions, coupons, bundle discount and subscription discount, cannot be stacked on top of other coupons. During promotional periods, discount codes will not be able to be applied to orders. Promo codes may apply to products only—filters, accessories, and new products within 3 months of the release date are not included.