What is an example of secondary pollutant?
Examples of a secondary pollutant include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight; NO2, which is formed as NO combines with oxygen in the air; and acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water.
What does NAAQS stand for?
National Ambient Air Quality Standards
The Clean Air Act requires EPA to set National Ambient Air Quality Standards (NAAQS) for pollutants that are common in outdoor air, considered harmful to public health and the environment, and that come from numerous and diverse sources.
What causes photochemical smog?
Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities. It tends to occur more often in summer, because that is when we have the most sunlight.
What are and list the 6 criteria pollutants?
EPA has established national ambient air quality standards (NAAQS) for six of the most common air pollutants— carbon monoxide, lead, ground-level ozone, particulate matter, nitrogen dioxide, and sulfur dioxide—known as “criteria” air pollutants (or simply “criteria pollutants”).
Is SO2 a secondary pollutant?
Sulfur dioxide is also a natural byproduct of volcanic activity. Like nitrogen dioxide, sulfur dioxide can create secondary pollutants once released into the air. Secondary pollutants formed with sulfur dioxide include sulfate aerosols, particulate matter, and acid rain.
Is SO2 a primary or secondary pollutant?
Examples of primary pollutants include sulfur dioxide (SO2), carbon monoxide (CO), nitrogen oxides (NOX), and particulate matter (PM). Examples of secondary pollutants include photochemical oxidants (ozone, nitrogen dioxide, sulfur trioxide) and secondary particulate matter.
Are NAAQS beneficial?
Partial attainment of the selected particulate matter (PM) National Ambient Air Quality Standards (NAAQS) is expected to yield national annual monetized benefits (health and welfare) of approximately $19 billion to $104 billion.
Is SO2 a component of photochemical smog?
Since SO2 is a reducing agent and photochemical smog is normally con- sidered to be an oxidizing system, an interaction would be expected. Atten- tion naturally is directed toward the reaction of SO2 with ozone, the major oxidant in photochemical smog.
What is another name for photochemical smog?
Photochemical smog, which is also known as “Los Angeles smog,” occurs most prominently in urban areas that have large numbers of automobiles. It requires neither smoke nor fog. This type of smog has its origin in the nitrogen oxides and hydrocarbon vapours emitted by automobiles…
What are the 5 major pollutants?
5 Major Outdoor Air Pollutants
- Ozone (O3)
- Nitrogen Oxides (NOx)
- Carbon Monoxide (CO)
- Sulfur Dioxide (SO2)
- Particulate Matter (PM10 and PM2.5)
What are the 7 criteria air pollutants?
The criteria air pollutants include particle pollution, ground-level ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. These pollutants can harm your health and the environment, and cause property damage.
What are the NAAQS standards for sulfur dioxide?
The Clean Air Act requires EPA to set national ambient air quality standards (NAAQS) for sulfur dioxide and five other pollutants considered harmful to public health and the environment (the other pollutants are ozone, particulate matter, nitrogen dioxide, carbon monoxide, and lead).
What does the proposed so 2 caaqs mean for vegetation?
3 ), most vegetation would be protected but there may be times when sensitive species such as lichens may not be, even if 8 ppb were not exceeded. From this, the proposed SO 2 CAAQS considered the range of hourly and annual air concentration based on existing monitoring stations data, and on predicted 2025 modelled SO 2
What are the caaqs?
The CAAQS are established as air quality objectives under the Canadian Environmental Protection Act, 1999. To assist with air quality management, provinces and territories have defined smaller geographic areas called air zones that divide their jurisdiction and that have unique air quality characteristics.
What are the major sources of SO2 in Ontario?
2 in Ontario include non-ferrous smelting and refining, petroleum refining, iron and steel industry, transportation sources (e.g. air and marine transportation), incinerators, and other industrial sources (e.g. cement plants, pulp and paper mills , chemical industry). Environment Canada estimated total SO