We often do not drive a car thinking of all the hazardous emissions we would release. Nor do we turn on the light with thought as to how that energy was generated. Yet, when we do all these activities subconsciously, we indirectly contribute to the growing amounts of hazardous air pollutants in our atmosphere that are responsible for many adversities.

In the case of energy, both productive and consumptive activities result in smog, a negative externality imposed on the environment and the welfare of society. The production of an output of energy through the process of burning coal or other fossil fuels, for example, releases two main air pollutants: sulfur dioxide and nitrogen oxides. Similarly, the consumption of energy-either for self-consumptive or other productive purposes-releases primary pollutants VOCs and nitrogen dioxides, which in turn can undergo chemical reactions to yield secondary pollutants such as ground level ozone and PAN. All these air pollutants are responsible for adverse effects in both humans and plants and on materials and aesthetics, as well as the negative impacts on the environment, namely acid rain. In whichever case, the stated price of either energy or an intermediate form of energy, such as gas, or a finished output that uses energy as an input, rarely reflects the complete burden placed upon society. This neglect of externalities, in turn, often results in an over-production or over-consumption of energy and other related goods. Here, we take a closer look at these externalities as to see what costs to society the market fails to account for.

Back to top

While the effects of smog vary according to factors such as age, state of health, time of exposure, and dosage, the general symptoms include coughing, sneezing, headaches, tiredness, irritation, nausea, and hoarseness of the throat, nose, and eyes, and constrictions of the chest (Lewis 37; Elsom 31). Additionally, nitrogen dioxide and ground-level ozone were found to cause reductions in the immune system's ability to fight bacteria and viruses in the respiratory system (Nebel and Wright 530; EPA, "Smog-Who Does it Hurt?" 3). These effects are all considered to be short-term in that once exposure ceases, the symptoms are no longer present. However, in most cases, it is the long-term effects of air pollutants that bring the greatest concerns, since these effects are often the most severe.

Unsurprisingly, most acute effects of smog are related to the respiratory system. Some components of smog such as nitrogen dioxide, sulfur dioxide, and ground-level ozone are found to have caused damages to the mucociliary system responsible for cleaning the air tracts (Elsom 56). As a result, the lung's ability to resist disease is reduced, and illnesses, such as bronchitis and emphysema, can be aggravated (Gow and Pidwirny; Elsom 56). Likewise, while some VOCs were found to be carcinogenic, the main problem with VOCs was its role in the formation of ground-level ozone. Present in ambient concentrations, ground-level ozone can cause inflammation and fibrosis to the lungs, resulting in permanent morphological changes to the lungs (Nebel and Wright 530; EPA, "Smog-Who Does it Hurt?" 3). Consequently, these air pollutants can not only decrease lung function, elasticity, and capacity by as much as 5%, but can also lead to the premature aging of the lungs (Elsom 33, 63; "Smog").

While continuous research is being made as to link the long-term effects of smog to human health, scientists in general have agreed on several findings. By and large, children, asthmatics, people with chronic respiratory or pulmonary and heart disease, and the elderly are the most susceptible to air pollutants (Nebel and Wright 530). Because the lungs of children are not yet fully developed and because children inhale more air per unit of body weight than adults, they are prone to greater health effects as well as long-term damage to the lungs (Elsom 42). Similarly, because asthmatics and those suffering from chronic diseases are already in a weakened state, smog adds stress to their bodies (Nebel and Wright 532). For the elderly, smog increases their susceptibility to viral and bacterial attacks, as both lung and immune system functions decrease with age (Elsom 42). Healthy adults who work actively outdoors or who have higher levels of exposure to air pollutant are also considered, by the EPA, to be in a "sensitive group" (EPA, "Smog-Who Does it Hurt?" 3).

In all these cases, it is important to note that contrary to popular belief, death as a result of a smog siege is often not a result of air pollutant poisoning, but rather, a result of increasing susceptibility to diseases. Equally important, however, is the fact that a great level of uncertainty exists in identifying a cause-and-effect relationship between smog and smog-related illnesses. At most, we can often only say that pollutants are contributing factors to related illnesses. Consequently, this makes the exact measurements of externalities difficult, if not impossible.

Estimates have been made, however, to provide a monetary value of the costs and benefits of smog. In several studies conducted by the American Lung Association, the costs of premature deaths, hospital stays and emergency room visits, productivity loss as a result of missing work or school, and other air pollutant related health effects were an indication of inefficiency within the economy ("Air"). The reports went so far as to argue that economic growth was correlated with environmental protection by demonstrating that human health benefits of cleaner air outweighed the costs industries would have to incur as a result of higher standards (ibid). It was estimated that enforcement of all parts of the Clean Air Act between 1970 and 1990 would result in minimum benefits of $23 trillion over the twenty years, an average of over $1 trillion annually (ibid).

In a similar study conducted by the EPA for United States Congress in 1999, it was estimated that if the Clean Air Act Amendments were enforced in the 48 contingent states for the twenty-year period between 1990 and 2010, the total human health benefits in 2000 would be $68 billion and $118 billion in 2010 (EPA, "The Benefits and Costs" H-27). These benefits represent underestimates, since, in the words of the EPA itself, "there is insufficient information from both the medical and the economic sciences to satisfactorily resolve these issues from a theoretically/analytical standpoint" (ibid. H-36).

Apparently, smog is a costly externality from a human health perspective alone.

Back to top

In numerical terms, ground-level ozone, alone, has been estimated to cause 10% to 40% growth loss, premature aging, and a decrease in pollen lifespan resulting in an estimable cost in agriculture of $2 billion to $6 billion per year (Nebel and Wright 533; "Smog"). Losses in crop yields were estimated to be 20% to 30% between 1989 and 1992 (Nebel and Wright 533). In Ontario alone, smog was attributed to reduce crop yields equivalent to $70 million per year ("Smog"). In a study conducted by the EPA to Congress, continuous implementation of a Clean Air Act Amendments over the period 1990 to 2010 would accumulate a minimum 1999 net present value of agricultural benefits of at least $4 billion (EPA, "The Benefits and Costs" F-8). Along with the fact that 60% of the world's food is produced in countries that also produce 60% of the world's air pollution, the significance of clean air is clearly seen (Nebel and Wright 533).

In a forestry aspect, smog incurs a cost on the existence value of trees and wild plants. In Los Angeles, smog was attributed to the deaths of 50% of trees in nearby areas (ibid.). Similarly, ground-level ozone from the Central Valley and San Francisco-Oakland metropolitan areas was responsible for increasing stress and vulnerability on the ponderosa and Jeffrey pines in the Sierra Nevada (ibid.). An attack by western pine beetles subsequently diminished the number of these trees.

As it perhaps can be predicted, the monetary costs of the loss of forests are difficult to measure, if measurable at all. Yet, it may still be worthwhile to keep in mind the option value benefits, non-consumptive use benefits, and existence value of forests, when making a balance sheet of costs and benefits of reducing smog. In another aspect, the damage to trees can have direct economic costs-as Canada discovered when it was found that ground-level ozone was the cause of damage to its sugar maple trees and other trees in its forestry industry ("Smog").

Back to top

The most visible characteristic of cities smothered by smog is perhaps the black and soot-covered windows, walls, drapes and curtains, and other exposed surfaces. Yet, other damages can be seen. Sulfur dioxide corrodes metal and stone-damaging machinery and industrial instruments, as well as destroying buildings, statues, and monuments (Lewis 33; EPA, "The Plain English"). Ground-level ozone, destroying synthetic materials, can cause leather to become brittle and rubber to lose its elasticity, resulting in cracks (Lewis 33). Moreover, ground-level ozone has been found to damage cotton, acetate, nylon, polyester, and other textiles, while bleaching dyes, paints, and coatings ("Smog").

While it is uncertain as to how much is exactly spent on the cleaning or replacement of materials, a couple of million dollars is considered to be a reasonable estimate. Canada, alone, estimates that the increase in ground-level ozone from the United States has cost it up to one billion dollars in material damages ("Smog"). Considering that cleaning and replacement costs do not include materials that are irreplaceable and the observation that people have actually spent more to move further away from cities, these costs of pollution most likely will be underestimates (Nebel and Wright 534).

Back to top

As a basic biology course will explain, slight deviations from pH values in the environment can be critical to the proper functioning of enzymes, hormones, and other proteins. In aquatic systems with a normal pH of 6 to 8, a slight deviation in most cases will pose no threat, as organisms adapt (Nebel and Wright 541). However, an organism's ability to successfully reproduce may be hindered, and in more extreme cases, a population of an organism may actually become extinct (ibid.). In forests, acid precipitation not only damages trees and plants, but also affects soil contents, which can thwart growth towards acid-tolerant species (ibid. 542). For humans, the effects of acid rain may vary from aesthetic values to the issue of clean water and air. In all of these cases, no exact monetary value can be assigned.

The fact that everyone and everything in the environment is interlinked in a chain demonstrates the difficulty in measuring an externality such as smog. Yet the simple recognition that such externalities exist can work wonders in policies attempting to ensure a more sustainable and healthier future.

Back to top