Air pollution

What is ozone?

What is Ozone in general?

Ozone or O3 is a highly reactive gas composed by three oxygen atoms. It is considered to be both a natural and a man-made product that occurs in the Earth’s upper atmosphere which is referred to as the Stratosphere and the lower atmosphere as the Troposphere. Depending on where it is in the atmosphere, ozone affects life on Earth positively or negatively.

How is Ozone made?

Ozone is formed when heat and sunlight causes chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) which are also referred to as Hydrocarbons. As said previously, the upper atmosphere is referred to as the Stratosphere and the lower as the Troposphere. A good way to differentiate the positive and negative is through that ozone is ‘good up high, bad nearby’.

The Stratosphere ozone being the good layer forms at 10-30 miles (numbers do fluxtuiate a source did say 6-30 miles. The Stratosphere forms a protective layer which is more well known as the ozone layer, it’s what we known to be shielding us from too much of the sun’s harmful ultraviolet rays (UV Radiation). This is formed through the interaction of the solar ultraviolet radiation alongside with molecular oxygen (O2).  

The Tropopspehric or the ground level ozone is what we breath, this is formed primarily from photochemical reactions between two major classes of air pollutants, volatile organic compounds like (VOC) and nitrogen oxides (NOx). These reactrions are commonly viewed to be dependent on the presence of heat and sunlight which helps reduce higher ambient ozone concentrations during the summer months. However, during these last few years, there have been sights of high ozone concentrations observed under specific circumstances in colder months. Ozone does have involvement in what we typically experience as ‘smog’ or haze, which generally still occurs frequently in summertime (This can still occur throughout the year even in some southern and mountainous regions). 

It’s good to note that even though Stratosphere ozone is transported into the troposphere and that some VOC and NOx occur naturally, the majority of ground-level ozone comes from the result of man-made VOC and NOx which is why it’s regarded as bad ozone. This type of ozone harms human health and the environment if it forms too close to the ground. Such as the previously stated man-made VOC and NOx which are produced via mobile source emissions and industrial processes. For VOC it can come up from chemical plants, gasoline pumps, oil-based paint. While Nitrogen Oxide results primarily from high-temperature combustion such as power plants, industrial furnaces as well as boilers and motor vehicles. Besides the UV radiation that comes from sunlight is also a significant impact on it as well.