Urban Air Around the World: An Overview2 min read
If we apply the air quality standard for particulates adopted by the European Union (20 micrograms per cubic meter), urban air pollution is nearly ubiquitous around the world. Of course, air pollution levels vary widely. In some parts of the world, air pollution might go unnoticed. In other places, people can be seen wearing face masks. As travelers, we need to know what we are getting into.
We’ve been digging into data compiled by the World Health Organization for nearly 140 countries, looking specifically at particulate levels in cities with a population of at least 100,000. This widely used measure of air pollution—called PM10 — counts both unnatural and natural particles less than 10 micrograms in diameter. We’re talking about things that are suspended in the air (both liquids and solids) and are less than 1/7th of a strand of hair in diameter.
Why keep track of particles of this size? The reason is that the smaller a particle is, the deeper it can settle in a person’s lungs. And the deeper it gets, the more damage it can do.
And a lot of damage is being done. Of the countries surveyed, only twelve met the EU air quality standard (see Table 1). The U.S. tied for seventeenth with Denmark and South Africa with a relatively clean score of 24. But in many countries around the world, the average urban particulate levels are two, three or four times higher. We put together Table 2 to highlight some frequently visited countries whose levels are a multiple of the U.S. reading. Short visits to urban areas of these countries could cause moderate to severe discomfort or a dangerous flare up of chronic respiratory problems. Long-term stays or relocations portend serious health risks.
We’ll expand our discussion in the coming days. Have you had breathing distress in a destination? How did you manage?