The United States is home to some of the most beautiful cities in the world, but unfortunately, it also has its share of the most polluted cities. Despite efforts to reduce pollution, many cities in the US continue to struggle with poor air quality due to various factors, including traffic congestion, industrial activities, and weather patterns. In this view, we will take a closer look at some of the most polluted cities in the United States.

Bakersfield, California: Bakersfield, located in California's Central Valley, consistently ranks as one of the most polluted cities in the US. The city's poor air quality is mainly due to its location, surrounded by mountains that trap pollutants in the air. Additionally, the city's heavy reliance on agriculture and oil production also contributes to high levels of air pollution.

Fresno, California: Another California city, Fresno, also struggles with poor air quality due to its location in the Central Valley. The city has high levels of ozone and particulate matter, which are harmful to human health. The primary source of pollution in Fresno is transportation, with the city having high traffic congestion levels.

Phoenix-Mesa-Scottsdale, Arizona: The Phoenix-Mesa-Scottsdale metropolitan area has consistently ranked as one of the most polluted cities in the US due to its high levels of particulate matter and ozone. The city's hot and dry weather conditions, combined with its high levels of traffic, make it challenging to maintain clean air.

Los Angeles-Long Beach-Anaheim, California: Los Angeles has been known for its smog and air pollution for decades. The city's location in a basin surrounded by mountains traps pollution in the air, and the city's heavy reliance on transportation and industrial activities contribute to high levels of air pollution.

Central Pennsylvania : This part of central Pennsylvania has distinct air pollution epicenters from other parts of the country. They are more like freckles scattered across the land than urban agglomerations.

In addition, they have a higher proportion of white residents than other hotspots; overall, 84% of the people living in the central Pennsylvania areas with the highest levels of fine particle air pollution are white. The region is home to a lot of agriculture, but it is also a major transportation route with clusters of food processing plants, metal fabricators, and plastics manufacturers.

Phoenix, Arizona : With good reason, the capital of Arizona is referred to as "the hottest city in America." There are 111 days per year when temperatures exceed 100 degrees Fahrenheit in Phoenix, with 145 days in 2020.

In 2020, the city's PM2.5 and ozone levels were above safe levels for 149 days due to extreme heatwaves. Ozone and high temperatures can make it difficult for people to breathe and cause illness.

Phoenix started a beautification project to cool the city by planting trees to absorb carbon dioxide and provide more shade. The city hopes to achieve "tree equity" by 2030, working with American Forests, to ensure that trees are distributed evenly and improve residents' quality of life.

Final words : Plans are in place to cut emissions and improve air quality for residents of even the most polluted cities in the United States. Sadly, it is difficult to reduce emissions caused by industrialization and rapid population growth. When moving to or visiting a polluted city, you can protect your health by staying inside and closing the windows during record ozone levels.