MEE 6501, Advanced Air Quality Control 1
Course Learning Outcomes for Unit IV
Upon completion of this unit, students should be able to:
- Assess health effects of air pollution. 3.1 Explain the natural air pollution variables causally related to adverse health effects on humans. 3.2 Summarize the anthropogenic air pollution variables causally related to adverse health effects on humans.
- Estimate the impact of air pollution on the environment.
Chapter 5: Health Effects
Chapter 12: Environmental Noise
The Guide for Obtaining Air Authorization in Texas is used with the permission of the Texas Commission on Environmental Quality. You can access the document from their website, or you can click on the link in the Unit II Mini Project in the syllabus.
Texas Commission on Environmental Quality. (2011). Surface coating facilities: A guide for obtaining air authorization in Texas. Retrieved from https://www.tceq.texas.gov/searchpage?cx=004888944831051571741%3Auk3yh4pey8&cof=FORID%3A11&q=Surface+Coating+Facilities%3A+A+Guide+for+Obtaining+Air+Auth orization+in+Texas
To date, we have discussed air pollution as being sourced either from natural or anthropogenic forces. In our reading for this unit, your authors thoroughly explain the health effects of air pollution and tie together air pollution and noise pollution in a rather unique manner. This strategy of tying together noise pollution and air pollution warrants further consideration than what is presented in our reading.
One of the interesting points that you may note as you progress through this program is that much of what is considered a pollutant to humans is actually already present in nature. This includes some of what is mentioned in our reading in this unit: aerosols (ocean spray), hydrocarbons (petroleum), oxides of nitrogen (tropical forests), ozone (elevated atmospheres), and heavy metals (lead, mercury, cadmium, chromium, etc.) (Godish, Davis, & Fu, 2015; Phalen & Phalen, 2013). A question could then be posed as to why or how natural phenomenon, energy sources, tropospheric nitrogen compounds, and naturally occurring elements are labeled environmental pollutants when in the presence of ecological or human life. This is an important consideration, given that most of the time we may consider only engineering ambient air quality back to levels found in “climax” nature.
The answer to the question may be found with a closer consideration to how humans interact within the environment. This includes anthropogenic acts such as exposing elemental sulfur through mining operations to rainfall events, thereby allowing an unmitigated exposure of the sulfur to water and creating sulfuric acid (H2SO4) (Hill & Feigl, 1987). Another example might be over-stocking cattle in a confined animal feeding operation (CAFO), thereby allowing an unmitigated concentration of methane gas into the immediate
UNIT IV STUDY GUIDE Engineering for Indoor Air Quality, Part Two
MEE 6501, Advanced Air Quality Control 2
UNIT x STUDY GUIDE Title
environment (impacting both ambient air and confined animal space air) that might otherwise be more evenly distributed in a range-grazing situation (Withgott & Brennan, 2011).
As such, the answer to balancing anthropogenic and natural variables causally related to air quality lies with our ability to engineer systems that work to minimize anthropogenic forces upon nature. This systems approach affords natural variables to minimally impact humans, while affording anthropogenic variables to minimally impact nature. The challenge for the air quality engineer is to understand the natural variables’ air emission potential in given situations, and to engineer the anthropogenic systems (such as our interior coating spray booth project) in such a manner that allows for the natural variables’ air emissions even while mitigating exposures of those emissions to humans.
For example, we understand that hydrocarbons have the natural potential to form volatile organic compounds (VOCs), even without human interaction in nature. However, we also see the use of hydrocarbon compounds in synthetic products such as interior coating materials and other paint products, and subsequently incorporate those hydrocarbons into our synthetic product designs. The engineer’s job then becomes one of learning to forecast and quantify the natural emission rates of the VOC from the hydrocarbon compounds contained as an ingredient in the synthetic paint products. Once the VOC emission rates have been forecasted for a given product, the work system (such as the interior coating spray booth process) can be evaluated for subsequent impacts to the ambient air environment and to human health. This often requires the air quality engineer to calculate emission rates into several different units of measure, to include poundage of VOC per product, poundage of VOC per hour of work exposure, poundage of VOC per year, and even tonnage of VOC per year (TCEQ, 2011). As such, the air quality engineer is practically taking something rather obscure like vapor and converting the VOC into something tangible as units of mass. When the VOC is converted into tangible units of mass as pounds or tons, statistical forecasting mathematics becomes possible (and consequently manageable) within the work system.
This concept of converting pollutants as abstract concentrations (or even percent by weight, as is common in industrial hygiene measurements) into tangible units of mass-based concentration like parts per million (ppm) or parts per billion (ppb) then becomes the air quality engineer’s primary unit of evaluation for airborne pollutants, given that ppm (as mg/L) and ppb (ug/L) can be expressed as units of mass-based concentration for almost any air pollutant represented (Phalen & Phalen, 2013).
Air quality assessments get even more interesting once the air quality engineer considers that noise may be treated as a form of either atmospheric or ambient pollution. Your textbook demonstrates this with the argument that sound energy causally related to “noise” is transmitted largely through the air environment. Suddenly, we find the need to also measure air quality through measures of dimensionless units of decibels (dB) in order to adequately evaluate air quality impacts on human health.