CO2

What is Carbon Dioxide – CO2

The Earth’s atmosphere is made up of a diverse mix of gases including 78% nitrogen (N), 21% oxygen (O) and roughly 1% additional gases that include about 0.04% carbon dioxide (CO2). Carbon dioxide is a highly common, naturally occurring gas that is colorless, odorless and consists of one carbon atom bonded to two oxygen atoms. CO2 plays an important role in the regulation of the Earth’s surface temperature through what is known as the Greenhouse Effect – the process whereby radiation from our planet’s atmosphere warms the surface of the planet to a temperature that exceeds what it would be without the presence of its atmosphere. Carbon dioxide is also a key player in the carbon cycle, a biochemical cycle where the element of carbon is exchanged between biological systems – from ocean to land, land to sky and atmosphere, and then sky and atmosphere back to the ocean. We exhale CO2, contributing to its presence in our atmosphere when we breathe and plants absorb this exhaled CO2 through the process of photosynthesis in order to grow. When there is too much carbon dioxide in the atmosphere as a greenhouse gas (GHG) it can pose problems for the livable temperature of the planet by trapping the energy of the sun and causing global warming.

What’s the Problem with CO2

The release of extra CO2 into the atmosphere through the burning of fossil fuels, for example, traps heat within the thin protective atmospheric film blanketing the earth, which causes a global warming phenomenon linked to climatic instability and major shifts in weather and natural conditions and formations. The Clean Air Act was established in 1963 by the United States Environmental Protection Agency (EPA) to regulate greenhouse gas emissions such as CO2 and to curb air pollution on a national scale.

NOx

What is Nitrogen Oxide – NOx

Nitrogen oxide, or oxides of nitrogen are atmospheric pollutants formed when fuel is burned at extremely high temperatures and it represents a highly reactive and poisonous family of gases. NOx is considered to be a pollutant and is emitted into the atmosphere through the exhaust of vehicles, trucks, heavy equipment, watercraft and industrial equipment and locations such as refineries and power plants. Brownish hued in color, NOx is considered an oxidizing agent that reacts with other atmospheric gases and particles as well as the volatile organic compounds (VOC’s) that produce smog, ground level ozone, haze, acid rain and fine particulates associated with a spectrum of health concerns.

What’s the Problem with NOx

Nitrogen dioxide is considered to be an irritant gas, causing respiratory conditions and allergies from inflammation of the airways and lungs when found in high concentrations. In heavily populated urban areas with extreme emission concentrations, NOx poses a significant health concern. The EPA created the National Ambient Air Quality Standards (NAAQS) for monitoring NOx, specifically nitrogen dioxide (NO2) in the atmosphere. The NAAQS manages air quality levels, keeping NO2 emissions at a relatively acceptable level of safety for public health and welfare.

Particulate Matter (PM)

What is PM, and how does it get into the air?

PM stands for particulate matter (also called particle pollution): the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope.

Particle pollution includes:

• PM10 : inhalable particles, with diameters that are generally 10 micrometers and smaller; and
• PM2.5: fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.
• How small is 2.5 micrometers? Think about a single hair from your head. The average human hair is about 70 micrometers in diameter – making it 30 times larger than the largest fine particle

Sources of PM

These particles come in many sizes and shapes and can be made up of hundreds of different chemicals.

Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires.

Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles.

What are the Harmful Effects of PM?

Particulate matter contains microscopic solids or liquid droplets that are so small that they can be inhaled and cause serious health problems. Some particles less than 10 micrometers in diameter can get deep into your lungs and some may even get into your bloodstream. Of these, particles less than 2.5 micrometers in diameter, also known as fine particles or PM2.5, pose the greatest risk to health.

Fine particles are also the main cause of reduced visibility (haze) in parts of the United States, including many of our treasured national parks and wilderness areas