Activity 3.3.1 Air Pollution Core Activity

Air Pollution Basics

Sulfur Pollutants

Has the most important gaseous air pollutant in its group, sulphur dioxide. Once oxidized it then becomes sulphate which takes 4 days till it decomposes. This results in pollutants traveling far from where it was first emitted. These long traveling emissions then react with other chemicals in the air to form hazardous chemicals like ammonium nitrate and even acid rain. Although volcanoes and wildfires emit sulfur pollutants like sulphur dioxide, humans are responsible for more than 75% of the Earth’s sulphur dioxide annual emissions (Freedman, 2018). Human production of these emissions are caused by burning coal and petroleum based fuel sources. Toxicity by sulphur gases can result in shorter vegetation growth, and humans can develop respiratory issues and illnesses by short extreme exposure or prolonged minor exposure (Freedman, 2018).

Nitrogen Pollutants

Contain nitrogen gases like nitric oxide, nitrogen dioxide, nitrous oxide, and ammonia. Nitric oxide, and Nitrogen dioxide are often considered as a complex, and are referred to as NOx. NOx naturally occurs by soil nutrients breaking down, lightning and wildfires (annually 430 million tons), and by humans by fossil fuel combustion and powerplants (annually 83 million tons)(Freedman, 2018). Toxicity by nitrogen is rare but not impossible, and aftermath of nitrogen pollutants in an environment include acid rain and acidic soil.

Hydrocarbon and Volatile Organic Compounds (VOCs)

Contain diverse groups of pollutants that are hydrogen and carbon based, like methane. Methane is produced when organic matter is fermented and release into the environment by fossil fuels, burping, livestock, and even by evaporating gasoline. Toxicity by VOCs are extremely dangerous in concentrated forms which very rarely occur in atmospheric conditions but can be found in workplaces as formaldehyde and benzene. (Freedman, 2018)

Pollutants

Referred to as ozone, and are split between the stratosphere and the troposphere which is closest to the ground. Ozone occurs naturally and protects us from the sun's harmful rays and has no pollutant effects on the living organisms on Earth. Ozone located in the troposphere damages vegetation, materials, and humans. The creation and disbursement of ozone and other photochemical pollutants react to the sun. Under the sun photochemical pollutants can synthesize and gather in colder denser areas. Therefore air quality conditions constantly change throughout the day when the sun rises and after it sets. Valleys, mountains, and basins suffer from air conditions known as inverse that can keep air trapped in their regions due to unique wind conditions that are in result to their geography and time of day, and can be dispersed by wind once the sun sets and stronger winds destabilize their dense collections (Freedman, 2018). Toxicity by photochemical pollutants can result is asthma and worsen lung conditions for humans, and for vegetation can return less yields. (Freedman, 2018)

Comparison of Current AQI

AQI stands for "Air Quality Index" and is used to measure daily air conditions for pollutants to inform local citizens pollution statistics to warn them of hazardous air quality. The AQI is used to predict what symptoms the local population may face by being exposed to the air after inhaling the air that day. 

	Time of Day	AQI Current	AQI Forecast	PM 2.5	O3
El Paso, TX (highest)	9 PM	118	N/A	118	45
San Antonio, TX (Local Area)	9 PM	45	N/A	45	27
Los Angeles, CA	7 PM	38	42	31	38

My local region near San Antonio, TX although has higher air pollutants of PM2.5 compared to Los Angeles, it has less ozone pollutants than Los Angeles. Currently El Paso, TX contains the worst AQI due to its air pollutants of PM2.5. This may be a result of conjoined efforts of Ciudad de Juarez and El Paso border each other and is a international commerce hub for production and transportation between the United States and Mexico.

Although Los Angeles is able to provide an AQI forecast, both cities in Texas did not have numerical data for estimations of the AQI data for the following day. These sources do not mention of any limiting of their data or possible predictions it can make and it could be due to numerous issues. Law regulations on environmental reporting may vary state by state, time of reporting may be inconclusive since Texas is nearing midnight, there may be insufficient or too many outliers to make a useful and accurate prediction for these regions, or the opposite since Los Angeles is greatly affected by ozone air pollutants, specifically O3, and inverse air conditions there may be more of a focus infrastructure and funding on providing air quality predictions to warn their region of extremely unhealthy conditions.

Comparison of Current PM 2.5/03

National Standard	San Antonio Current (measured over an hour)	Time of Day
PM2.5  Average measured over 24 hours - 35 μg/m3	PM2.5 of 11.9 μg/m3	9 PM Central Time
O3  Average measured over 8 hours - 70 ppb (137 µg/m3)	O3 of 28ppb = ~ 56μg/m3	9 PM Central Time

PM2.5 are air particles that are smaller than 2.5 micrometers and can cause damage to respiratory system due to how small they are and easily go through holes in your respiratory system. Therefore this can easily avoid or at least not alert your immune system to significant hazardous air quality, eventually even depositing harmful materials in your circulatory system. For an example of how small PM2.5s are, a single strand of hair is 50 to 70 micrometers thick.

O3 is used to refer to ozone, a photochemical air pollutant that directly negatively affects living organisms. It is measured by parts per billon per kilogram (ppb) and can cause minor injuries to vegetation and respiratory systems if exposed for hours. Southern regions of the United States are in risk due to higher exposure to O3, for example Los Angeles can see measures of 500ppb during their hottest days of the year.

Reference(s)

Freedman, B. (2018). Environmental science: A Canadian perspective. Halifax, Canada: Dalhousie University Libraries.

U.S. Environmental Protection Agency (EPA). (2019, June 18).Air quality index basics. Air Now. https://airnow.gov/index.cfm?action=aqibasics.aqi

U.S. Environmental Protection Agency(EPA), NAAQS Table. EPA.gov. https://www.epa.gov/criteria-air-pollutants/naaqs-table