In accordance with the World Health Organization's guidelines, the air quality in the United States of America is considered safe. The most recent data indicates the country's annual mean concentration of PM2.5 is 7 µg/m3 which falls below the recommended maximum of 10 µg/m3.
Air quality in the USA can be negatively affected by the petroleum, steel, lumber, mining, and aerospace industries, food processing, vehicle emissions, and forest fires. Seasonal variations exist, with higher levels of air pollution in the summer and fall (May to December) on the west coast due to forest fires. Available data indicates that Bakersfield, Visalia-Porterville, Hanford, Portola, and Elkhart-Goshen are cities that can experience high levels of air pollution.
Outdoor air pollution is a mix of chemicals, particulate matter, and biological materials that react with each other to form tiny hazardous particles. It contributes to breathing problems, chronic diseases, increased hospitalization, and premature mortality.
The concentration of particulate matter (PM) is a key air quality indicator since it is the most common air pollutant that affects short term and long term health. Two sizes of particulate matter are used to analyze air quality; fine particles with a diameter of less than 2.5 µm or PM2.5 and coarse particles with a diameter of less than 10 µm or PM10. PM2.5 particles are more concerning because their small size allows them to travel deeper into the cardiopulmonary system.
The World Health Organization’s air quality guidelines recommend that the annual mean concentrations of PM2.5 should not exceed 10 µg/m3 and 20 µg/m3 for PM10.
Cities and rural areas worldwide are affected by air pollution. When planning a trip, consider health status, age, destination, length of trip and season to mitigate the effects of air pollution.
Short term symptoms resulting from exposure to air pollution include itchy eyes, nose and throat, wheezing, coughing, shortness of breath, chest pain, headaches, nausea, and upper respiratory infections (bronchitis and pneumonia). It also exacerbates asthma and emphysema. Long term effects include lung cancer, cardiovascular disease, chronic respiratory illness, and developing allergies. Air pollution is also associated with heart attacks and strokes.
See city and country air pollution levels:
Information last updated: April 16, 2020