Air Quality Worse in Summer
Air quality decreases during times of hot temperatures because the heat and sunlight essentially cook the air along with all the chemical compounds lingering within it. These heated chemicals combine with the nitrogen oxide emissions present in the air, creating a “smog” of ground-level ozone gas.
This makes breathing difficult for those who already have respiratory ailments or heart problems and can also make healthy people more susceptible to respiratory infections.
According to the U.S. Environmental Protection Agency (EPA), urban areas are the most susceptible because of all the pollution being emitted from cars, trucks, and buses. The burning of fossil fuels at power plants also emits a considerable amount of smog-making pollution.
Geography is also a factor. Broad industrialized valleys penned in by mountain ranges, such as the Los Angeles basin, tend to trap smog, making air quality poor and life miserable for those people working or playing outside on hot summer days. In Salt Lake City, the reverse happens: after a snowstorm, cold air fills the snow-covered valleys, creating a lid from which the smog cannot escape.
Those living in at-risk locations are advised to use public transit and carpooling to reduce vehicle emissions, refuel cars at night to prevent escaping gas vapors from getting cooked into smog by sunlight, avoid gas-powered lawn equipment, set air conditioning thermostats a few degrees higher to help reduce the fossil fuel burning needed to power them, and limit outdoor physical activity on poor air quality days.
Source: msn.com