Yes, sulfur dioxide (SO₂) absolutely causes air pollution.
Sulfur dioxide is explicitly recognized as a significant air pollutant. According to the reference provided, sulfur dioxide is categorized as one of the six common air pollutants known as criteria pollutants.
Understanding Criteria Pollutants
Criteria pollutants are a specific group of air pollutants that the U.S. Environmental Protection Agency (EPA) is required to regulate. They are called "criteria" pollutants because the EPA has developed health and welfare-based criteria (standards) for setting permissible levels in outdoor air.
- Regulation: These pollutants are subject to rigorous standards under the federal Clean Air Act.
- Standards: The National Ambient Air Quality Standards (NAAQS) define the maximum allowable concentrations of these pollutants in the ambient (outdoor) air. These standards are set at primary and secondary levels:
- Primary Standards: Protect public health, including the health of sensitive populations such as asthmatics, children, and the elderly.
- Secondary Standards: Protect public welfare, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings.
Being classified as a criteria pollutant like sulfur dioxide means its presence in the air is monitored, regulated, and controlled because it is known to have harmful effects.
Impacts of Sulfur Dioxide
As an air pollutant, sulfur dioxide contributes to various environmental and health problems.
- Health Effects: Exposure can affect the respiratory system, particularly for people with asthma.
- Environmental Effects:
- Forms acid rain when it reacts with water, oxygen, and other chemicals in the atmosphere. Acid rain can harm ecosystems, damage forests, and corrode buildings.
- Contributes to the formation of fine particulate matter, which can reduce visibility and cause respiratory issues.
Because sulfur dioxide is a criteria pollutant, its levels are tracked, and regulations are in place to reduce emissions primarily from sources like power plants and industrial facilities that burn fossil fuels containing sulfur.
