Seattle-Tacoma International Airport - Environmental Issues

Airplane Landing in the Fog at Night

Seattle-Tacoma International Airport

In my recent article, "Externalities and Risks, the Seattle-Tacoma International Airport", I discussed externalities associated with Airport operations.  The Airport environment presents a number of environmental issues, many of which are impacted by meteorological factors.

Fog is an important risk factor.  Fog reduces visibility, and although airports have radar systems, fog is still a hazard for pilots to be aware of.  Fog is a cloud at ground level, water droplets or ice suspended in air.  Suspended particulates or gas molecules can provide a nucleus around which water droplets or ice can form, thus encouraging the formation of clouds.  Enucleated pollutants, such as sulfur dioxide gain an easier entry into the respiratory system, increasing the impact on health.

During the fall, winter and spring, when temperature inversions form, often in the wake of high pressure systems, there is an increased risk from pollutants, often accompanied by fog.  This is especially true in the Pacific Northwest with the influence of marine air from the Pacific Ocean.  

A normal temperature gradient is warmer air on the surface and colder air aloft.  A temperature inversion reverses the normal gradient, trapping colder air on the bottom layer, with warmer air aloft.

Temperature inversions early this year influenced the snow pack in the mountains, as temperatures warmed aloft.  Temperature inversions can impact the levels of ice pack and the availability of water from mountain sources.  Because pollutants are trapped with the warm air aloft and the cold air on the bottom,  pollutants are trapped within a lesser layer of air, increasing the density of pollutants. These conditions lead to air stagnation advisories and burn bans, which are called by the Puget Sound Clean Air Agency.

Climate change and global warming may impact a variety of meteorological factors, increasing severity.  Other meteorological factors affecting air traffic may include wind shear, thunderstorms, snow storms and heat, which is of concern in the southwest, where a certain air density is required for take off.

Pollutants from aviation operations are a concern.  Pollutants are the product of combustion of aircraft fuel, burning of oils and solvents as well as particulate matter which may become abraded especially during take off and landing (TO/L) where the stresses on parts are higher.

Aircraft emissions include a variety of gases, including those of interest in analysis of climate change and global warming.  These gases include carbon dioxide, methane, nitrous oxide, nitrogen oxides, volatile organic compounds, carbon monoxide and sulfur dioxide. 

A study by the Federal Aviation Administration (FAA) gives a comprehensive study of aircraft emissions.

The components of aircraft emissions may vary depending on whether they are aloft, and considered greenhouse gasses, or local air quality pollutants.  " Aircraft engine emissions are roughly composed of about 70 percent CO2, a little less than 30 percent H2O, and less than 1 percent each of NOx, CO, SOx, VOC, particulates, and other trace components including HAPs."

About ten percent (10%) of aircraft emissions, except for carbon monoxide and hydrocarbons occur at ground level.  Thirty percent (30%) of Carbon monoxide and hydrocarbon emissions from aircraft occur at ground level.

Carbon Dioxide and Nitric oxides, and methane, as well as water vapor have significant contributions to climate change and global warming. Ozone is also an issue with aircraft emissions, although the effect is felt downwind due to the impact and timing of the photochemical effect that produces ozone.

The airport industry, according to industry source Air Transport Action Group (ATAG), produces 2% of world carbon dioxide emissions and 12% of carbon dioxide emissions from transportation sources. The impact of carbon dioxide may be more significant before springtime, when leaves emerge on the deciduous trees.  Levels of carbon dioxide in the atmosphere can be illustrated by the Keeling Curve which graphs levels of carbon dioxide in the atmosphere over time. One concern is that carbon dioxide emissions may impact feedback mechanisms that determine breathing patterns and modulate delivery of oxygen throughout the body.

An Airport Report Quality Manual published by the International Civil Aviation Organization discusses Airport Pollution issues. They discuss various particulate matter of varying sizes (10 micrometers or less, or PM2.5 of 2.5 micrometers or less.  Particulate matter "has a very diverse composition (heavy metals, sulphates, nitrates, ammonium, organic carbons, polycyclic aromatic hydrocarbons, dioxins/furans)."

The manual states: "Effects: fine particles and soot can cause respiratory and cardiovascular disorders, increased mortality and cancer risk; dust deposition can cause contamination of the soil, plants and also, via the food chain, human exposure to heavy metals and dioxins/furans contained in dust."

Air pollution impacts many systems. Respiratory systems, in particular, are affected, impacting the delivery of oxygen to the bloodstream, and thus to the brain, affecting the respiratory muscles and vasculature, and impacting sleep.  Air Pollution and the Respiratory System is a comprehensive journal article discussing the topic.  Cardiovascular systems also are impacted.  Air quality issues raise a number of concerns.

Noise pollution from airport operations also have a significant impact.  Meteorological conditions also affect the sound propagation, or noise emissions from airport operations.  According the "Encyclopedia of the Earth", microclimate effects can impact the refraction of sound waves through the atmosphere, intensifying sound levels.  Noise emissions may result in a variety of physiological and psychological impacts, including cardiovascular effects.  Such effects may reflect exposure to short, high intensity effects from jet engine backblast, to longer term impacts of exposure to moderate sound levels.

Emissions from Airport operations play an important role in contributing to pollution, both in the immediate area of the airport, in a larger, regional context, and with regards to global issues of planetary climate change and global warming.   Externalities from such emissions encapsulate the full downstream effects of these emissions, which impact citizens who may incur the cost of such emissions but not share in the economic benefits that the airport brings to the region.

Meteorological conditions affect the deposition of such emissions, near or far, through the atmosphere, in soil or water, or perhaps deposited in human tissue, blood or other organs of the body. Thus the effects of emissions on water systems is important  It is interesting to note that the human body is about 55% to 65% water, depending on who and what is being measured, so that the study of water systems can include the atmosphere, rivers, lakes, oceans, and even the human body.

Given the dispersion and deposition of emissions from airport operations, a challenge is to pluck out the impacts attributable to airport operations from other sources surrounding the airport, some of which are directly related to, and gain from, the airport's presence.  This issue brings me back to the original blog article on "Externalities and Risks, the Seattle-Tacoma International Airport",

Future blog articles will further explore these issues, taking into account current locally available information, assessing the measurement of risks, and considering means of compensating those impacted for the economic and social burden of the externalities in question. These are important issues that have implications for both local and global health, extending into physiological and psychological areas that impact humanity.

Blog Articles:
Externalities and Risk - The Seattle Tacoma International Airport
Climate Change and Carbon 

Climate Change and Global Health

World Health Organization Report on Air Pollution and Health

Climate Change and Global Health

Storm Surge Flooding, Westport, Washington, November 2009

Climate Change and Global Health

Climate change poses a number of risks to global health.  These risks draw our attention to the fact that health issues operate on a scale that transcends our own individual concerns, extending well beyond local communities, state and national boundaries.  

I attended a lecture in February, 2011, by Dr Howard Frumkin, Dean of the University of Washington School of Public Health on the health risks of climate change.  It was an interesting talk, covering many areas where climate change impacts global health. These impacts may be associated with the increased frequency of extreme weather events. 

Extreme weather events discussed included increased heat, cold, melting, freezing, flooding and droughts.  Increased atmospheric instability may give rise to more frequent hurricanes and tornadoes. Extreme weather events can be viewed on various time scales, from 50 to 100 year storms, to events on a more geological time scale.

Heat stress is of particular concern to the elderly, the young and the immune-compromised. Extreme heat, especially in non or inadequately air-conditioned spaces may result in premature mortality during heat waves, in the vulnerable, especially in the city where paved areas draw heat.  Dr Frumkin was concerned about the "harvesting" effect of heat waves on elderly, urban, populations.

Cold, snow, ice and freezing also may become survivability issues, involving issues of heating and interruption of water and electrical service.  Storms may impact travel and thus food supply, transportation of vital supplies to population centers and medical facilities.  

Public health challenges may emerge with air or water quality issues, impacting respiratory, cardiovascular, and other associated systems.  Infectious diseases may spread via the air or water through vectors  such as tic or mosquitoes, or via zoonotic means through human to animal or animal to human spread).  Allergies may develop in response to climate changes, and new pathogens may emerge or spread to different areas.

Air pollution is a problem which affects more than just urban areas.  With experience working in the regulatory air quality sector, I realize the widespread impacts that pollutants such as ozone and other pollutants have.  Photochemical reactions involving products of combustion (e.g. auto exhaust) take place in the atmosphere resulting in ozone levels downwind of major urban areas. As the reactions involve sunlight and heat, the levels on sunny and hot days increase in the summer. In the fall and spring periods of extended air stagnation resulting from stalled high pressure weather systems may increase the respiratory and cardiovascular burden on the vulnerable patient group. Air pollution does not know boundaries, thus residential and industrial pollution from other countries may impact us, as ours impacts theirs.  Forest fires add to the impact.  Extreme weather may impact all these issues.

The impact of climate change, extreme weather events and public health challenges may impact food production, may result in civil conflict, dislocation of impacted people and may increase the expression of mental health issues .

The discussion of climate science drives the discussion on public health impacts as projections are made regarding the manner in which changes will take place in Earth's climate systems.  Modeling climate systems drives downstream weather and public health challenges. These challenges are studied in a variety of settings, including federal government institutions such as NOAA, NASA and the CDC, and at a variety of state and local governmental and, at private institutions.  The Intergovernmental Panel of Climate Change and the National Climate Assessment have comprehensive plans reflecting policy in this area.

Extreme weather events can result in significant mortality and morbidity, as well as impacts to property.  Tornadoes and Hurricanes and wind storms may result in death and injuries from flying objects, falling trees and power lines as well as medical emergencies secondary to the event.  Fires may result from damaged gas lines. 

Increased flooding and storm surge may result in drownings and damage to property. Flooding may increased the spread of infectious diseases, problems with sewage systems and interruptions in drinking supplies

Drought may bring about reductions in food supply.  This is a serious issue as crops may be challenged to grow in areas where they were previously able to.  Vegetation, vectors and pathogens may spread into other areas as a result of warming.  This impacts the latitude at which such impacts occur as well as the altitude above sea level, moving to cooler latitudes and elevations.

More weeds may develop in urban areas in response to climate change and global warming as vegetation adjusts to the changing environment.

Extreme weather events thus may have public health impacts relating to many systems, resulting in dislocation of people and mental health issues as citizens adjust to the events.

The challenge is how to address climate change issues in the context of these public health issues.

Calculating Odds and Probabilities

1986 Liberty Half Dollar Tossed on Grass (Heads) (Image on Photoshelter)


A team will have an opportunity to call “heads or tails” for a coin toss at the beginning of a football game. If the call is successful, heads in the case of the coin pictured above, the team will have the opportunity to chose to take the ball (go on offense) or defend a particular goal. The choices are non-trivial as a team’s defense may be superior to their offense, or the wind may determine the choice of the goal defended. These choices represent the team’s expectations of their success, given their strengths, weaknesses and prevailing conditions.

The coin toss, for a fair coin, will give a probability (p) of .5, or 50% that the call (either heads or tails) will be successful. Coins flipped successively will tend, over a period of time to “revert to the mean”, or tend towards their expected value of 50% heads and 50% tails. The odds ratio for the coin toss is 1:1. Odds ratio is calcuated as the ratio of the probability of the event happening (p) to the probability that it won’t happen (1-p). Thus, out of 2 possible outcomes (heads or tails), one outcome (out of 2) is successful, one outcome (out of 2) is unsuccessful, for a ratio of 1:1.

While the coin toss is random, there is a balance of risks involved in the result. For example, a team with a superior offense can choose to go on offense, sputter on three downs, punt, and turn the ball over to the other team in good field position, despite their expectation of offensive success.


Two Sixes Dice Toss (infrared digital effect) (image on Photoshelter)

People use probabilities and odd ratios in their daily lives, consciously and unconsciously computing expectations and making decisions based on those expectations.

Some may choose to gamble on the roll of the dice. In this case, the probability of rolling two sixes is (1/36) while the odds are 1 to 35 (1 good outcome, 35 losing outcomes). When gambling in an establishment, the house will include a margin in for themselves, to cover expenses and profit. Given fair dice, the underlying odds (and the probabilities) will tend towards their mathematical expected value (1 to 35 and 1/36), thus giving over time a margin to the house.

Mathematical models can calculate the odds that there will be a city rivalry World Series this year, the odds of a particular candidate winning the 2012 election, and many other events.

Of particular interest are the mathematical models that deal with environmental issues, such as weather and climate change, given the emergence of extreme weather events.

Albert Einstein was quoted as saying “I, at any rate, am convinced that He does not throw dice.” (paraphrased as “God does not play dice with the universe”). However Stephen Hawking is quoted as saying “So Einstein was wrong when he said, "God does not play dice." Consideration of black holes suggests, not only that God does play dice, but that he sometimes confuses us by throwing them where they can't be seen”.

The National Oceanographic and Atmospheric Administration (NOAA) has sophisticated climatological models which forecast the weather, and they are continually improving these models in order to provide the maximum amount of warning possible to the populace. Through their efforts, NOAA is seeking to minimize the amount of risk, and maximize the information provided, seeking the “load the dice” in the publics favor.

We rely on weather forecasts in our daily plans. Should we call off the company picnic with a 70% chance of thunderstorms? How about that outdoor wedding? Do you pack the rain slicker or umbrella or leave it behind? Governments and businesses rely on weather forecasts for their daily operations and long term plans. Seasonal hurricane forecasts are looked at with interest by many sectors in planning ahead into the coming hurricane season.

Two United States Coast Guard Cutters monitoring the Westport, Washington Bar entrance (image on Photoshelter)

Nowhere is the issue of balance of risks and weather forecasting more apparent than in the maritime arena. When is the storm predicted to arrive? Is there a confidence interval around that arrival time, as well as its expected intensity? Sailors will balance the risk of venturing out and making headway to their destination versus the risk that the weather will take an unexpected turn for the worse, making for difficult, or hazardous headway, or worse.

The United States Coast Guard (USCG) is a branch of the U.S. Armed forces and is charged with maritime safety, security and stewardship. In this image, the two Coast Guard Cutters are monitoring the closed Westport Bar / navigational entrance from the Pacific Ocean to Westport, Washington. The USCG monitors ongoing conditions and weather forecasts to decide whether or not to close the bar, thus managing safety for mariners. The United States Coast Guard, in its decision-making, relies on the concept of balance of risk, as it makes decisions that affect the public. The public, in turn, makes decisions using balance of risk as it relies on NOAA guidance, the actions of the Coast Guard, and other factors.

It is human nature to calculate probabilities, calculate odds, consciously or unconsciously assess balance of risks. We do so continuously in our daily lives and rely on others to help us do so. We need to expand that awareness to include the risks we face due to environmental changes, consider the balance of risks inherent in the evolving situation, and find a way to meet the considerable challenges head on.

Risk

Fishing Boat off Cape Arago, Oregon (barely visible at right)

In all manner of things, large and small, we weigh our risks. Do we bring our umbrella with us to the theater or walk in the light rain? Do we take the first parking space or try to find a closer one and risk losing our space? We process these types of risk/benefit decisions continually as these everyday decisions are thrown at us in the course of our lives. The relative weight we give these outcomes changes over time and by circumstance. For example, if we are fighting off a cold we may be more apt to bring the umbrella.

Larger risks represent greater challenges. The stakes are higher, more is on the line and the effect of the risk may be more difficult to quantify. In the image shown of the fishing boat off Cape Arago in rough weather, there are potential risks involving life and property with deteriorating conditions. The sturdiness of the vessel, condition of its engine and electronics and human elements all have impacts on the risk equation as do the emerging weather and sea conditions.

Major geological events present even greater risks, with very low probabilities of occurrence and severe loss potential. Haiti's 2010, 7.0 earthquake represents the actual realization of earthquake risk, expressed in its full and devastating horror. Before the 7.0 earthquake, there was earthquake potentiality. Afterward, there has been pain, loss and devastation, as the world continues to watch the situation unfold.

It has been heartening to see the global response, coming to the aid of Haiti. The World's hopes and wishes are with the people of Haiti and those providing relief. The Help for Haiti icon directs the reader to the White House site for Haiti Earthquake Relief.