The U.S. may have cut down on its air pollution, but its western skies are still choked with smog.
In recent years, the U.S. has reduced its nitrogen oxide emissions by around 50%. Emissions from Asian countries, however, has negatively impacted the U.S.'s improved air quality. Polluted air has traveled over the Pacific Ocean and onto the western parts of the U.S.
Experts from a number of concerned agencies have teamed up to study the causes of smog in the western U.S. The researchers studied gound-level ozone over the years 1980 to 2014. They also considered pollution levels in the U.S. Data from Joshua Tree National Park in California and the eastern parts of the U.S. also played an important role.
The researchers discovered that rising emissions in Asia were the catalyst for rising ozone levels in western U.S. It's important to note that ozone is a key component in smog.
China and India are apparently the biggest culprits. Both are manufacturing giants, and factory emissions play a significant role in the poor quality of the two countries' air. Asian nitrogen oxide emissions have reportedly tripled over the last almost three decades. Nitrogen oxide, a common emission in Asian countries, produces ozone when broken down by sunlight. The ozone produced in these countries has contributed to over half of the increase of Western ozone.
The negative health effects of air pollutants are well known. High ozone levels can irritate the respiratory system for several hours after exposure. A high density of pollutants can also trigger asthma attacks and cause lung infections. Children and the elderly are particularly susceptible to these negative effects.
Various cities around the world experience varying levels of smog. Some experience the worst of it in particular seasons. In some cities, air pollution has become so thick and even deadly. While many have learned to live with poor air quality, it's something that needs to be addressed worldwide.
Beijing has recently made headlines due to footage of thick layers of smog descending over the city. Researchers at Nanjing University even found that extremely polluted air was the cause of a third of all deaths in China.
Families in Beijing are finding ways to cope with the poor, almost toxic air quality in their city. However, doing so is becoming a burdensome expense.
Los Angeles, on the west coast of the U.S., is also no stranger to poor air quality. Because of its geographical situation and weather patterns, Los Angeles is vulnerable to the accumulation of ozone.
Though China has been cutting down on nitrogen oxide emissions, there is still India to consider. In fact, India is reportedly more efficient in producing ozone. The Indian city of Delhi is even considered to be the most polluted city in the world.
The world's atmosphere knows no geographical bounds. Emissions produced by one country does not stay in that country's atmosphere alone. Researchers are pushing for “a global perspective” in meeting air quality objectives. Now that we know that smog can travel from continent to continent, it's no longer a localized problem.
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