International Air Quality Advisory Board
SPECIAL REPORT ON
TRANSBOUNDARY AIR QUALITY ISSUES
November 1998
9. EMERGING AND ANTICIPATORY ISSUES
9.1 Coal-Fired Power Plants
Throughout this report, the Board has identified the major environmental and human health threats from air pollution in the boundary region. These threats vary from region to region. The emissions of concern, however, have several common sources, the major contributors being fossil fuel power plants, transportation, and industrial processes. For some of these sources, much is known, and policies that will achieve significant reductions in emissions need to be implemented. This will involve putting in place comprehensive emission controls in both countries.
Concerns about power plants can be broken into two categories: new facilities and currently operating facilities. As the electricity grid in both countries becomes more integrated (as seen by the increase in Canadian exports of electrical energy to the United States shown in Figure 9-1), emission reductions must take place in both countries. Air emissions from new facilities can be well controlled, and emissions control technology can readily be designed into the construction of such facilities. Both countries have New Source Review (NSR) programs to ensure that new facilities are fitted with the best available control technology. With proper maintenance and operation, the emissions from a new facility are a small fraction of those from an uncontrolled plant. Because of this environmental advantage, it will be important for new facilities to assume more of the total energy generating capacity.
Figure 9-1
U.S. Electricity Imports/Canadian Exports
Graph prepared by IJC from data in Electric Power Annual 1996, Volume II,
U.S. Department of Energy.
For existing power plants, the story is much different. A significant portion of these plants which generate electricity through the combustion of coal has generally been exempt from comprehensive control requirements. Early efforts to control emissions led to the placement of limited technology in some of these facilities; some constructed stacks to allow the pollution to be more widely dispersed. It is these existing facilities with relatively high emissions, which contribute to the elevated concentrations of PM2.5, ozone, acidifying air pollution, and PTSs. To successfully abate the formation of PM2.5 and ozone, and emissions of acidifying pollutants and PTSs, comprehensive controls on these facilities are essential. Controls could be achieved through the establishment of an "Old Source Review" program, similar to the NSR programs for new facilities.
Significant new information has recently become available regarding emissions of hazardous substances from the electrical generation (particularly coal-fired utilities) sector.
The U.S. EPA recently issued two studies, the Mercury Report to Congress and a Study of Hazardous Pollutants from Electrical Utilities. These two reports confirmed that the electrical generation (coal-fired) source sector is a factor in the continued release of PTSs (particularly mercury) into the environment. The Board plans to continue assessing these and other documents to determine appropriate emission reduction objectives and strategies for this segment of the electrical generation sector.
9.2 Mobile Sources
9.2.1 Energy Conservation
For a variety of reasons, including the recent outcome of climate change negotiations in Kyoto, Japan, governments will need to support sound energy policies that can concurrently reduce emissions of NOX and other pollutants. Such policies could include incorporating the true total cost of energy into consumer energy prices and increasing the U.S. Corporate Average Fuel Economy (CAFE) standards for automobiles. Raising current CAFE standards could present a powerful opportunity to address a variety of air pollution problems, including NOX emissions. Since the mid-1970s and early 1980s, no progress has been made in increasing the fuel efficiency of motor vehicles (see Figure 9-2). In fact, the introduction of heavier and less fuel-efficient "sport utility vehicles" has reversed any gains made prior to that time. This situation is compounded by the fact that there are now more vehicles traveling greater distances every year.
Figure 9-2
New Car Corporate Average Fuel Economy by Model year.
American Automobile Manufacturers Association, Facts & Figures, 1997
These current vehicle trends indicate a need to develop increasingly fuel-efficient vehicles and to promote policies that encourage the purchase and use of low-emission and zero-emission vehicles(LEVs and ZEVs). Currently, the major automobile manufacturers have indicated that LEVs will be available at a reasonable cost in the next few years. While inclusion of such vehicles in the traffic mix has air quality benefits, it will take many years before LEVs and ZEVs will be the dominant segment of the U.S. and Canadian passenger car fleet. At the same time, major investments must be made in mass transit systems to promote their use and to reduce reliance on motor vehicles. All these measures have the potential to concurrently reduce energy use and reduce total emissions of NOX from the motor vehicle sector.
9.2.2 Sulfur in Gasoline
High sulfur content in gasoline is a concern in both the United States and Canada, particularly in regions where the resultant SO2 from auto emissions worsen air quality. As shown in Figure 9-3, gasoline outside of the state of California contains about 400 ppm of sulfur. Gasoline with the highest sulfur content (553 ppm) is used in southern Ontario, worsening the already compromised air quality in that area. Toronto's gasoline sulfur emissions are the highest in Canada.
Figure 9-3
Sulphur content of unleaded gasoline, summer of 1995
Initiative on the Potential Impact of Sulfur in Gasoline on Motor Vehicle Pollution Control and
Monitoring Technologies, Southam Newspapers - March 2.
The Canadian refining industry, built to process light sweet crude oil, has invested significant funds over the past decade in technology to process sour or high sulfur crude from Western Canadian heavy oil and tar sands sources. It is estimated that meeting the California gasoline standard of 30 ppm sulfur by these refineries would require an investment of $1.78 billion or an increase in the cost of gasoline of 1 cent per litre (3.78 cents per gallon).
In addition to the direct reduction in sulfur dioxide emissions that would be realized in both countries from all vehicles using lower sulfur fuel, more importantly, auto manufacturers are promoting the production of such fuel as crucial to the effectiveness of emission controls on current cars and future LEVs.
Within two years, Honda, Toyota, and General Motors will have the capacity to sell "virtually no emissions" vehicles (Z-LEVs). The exhaust gases from Z-LEVs will be nearly free of CO and NOX, and emit only 0.002 grams of non-methane organic gases per kilometre (0.00014 ounces per mile), a level 94 per cent below the voluntary higher standard agreed to by most major auto makers. Because high sulfur levels in gasoline will interfere with the proper operation of these systems, however, the full benefit of cleaner auto emissions will be realized only if the sulfur content is reduced significantly on a national basis in both countries.
9.2.3 Diesel Particulates, PM2.5 Precursors, and Co-Pollutants
After it was demonstrated that PM10 levels are associated with a variety of adverse health effects, data were assembled and reviewed by the U.S. EPA that suggested that the particles less than 2.5 microns in diameter (PM2.5) were the most significant contributors to adverse health effects. In some urban regions, such as London, England, where more than 17,000 taxis are driven by small diesel engines along throughways with a high proportion of heavy diesel traffic, diesel particles may be the predominant species within the PM2.5 fraction. In Holland, it has been shown that people who reside adjacent to motorways have higher exposures to such particles, and that the risk of lower respiratory infections or depressed lung function in children is thereby increased. There is also experimental and epidemiological evidence that increased exposure to diesel emissions increases the risk of lung cancer. It is not known, however, precisely what component of such particles increases their toxicity or carcinogenicity.
It may therefore be anticipated that considerable effort in the future will be devoted to developing measures that might reduce diesel emissions. One obstacle to this is that although new diesel engines do not emit high levels of particles, they emit increasingly higher levels as they get older. Alternative engines, such as those using natural gas or new fuel-cell technology, offer solutions that would greatly reduce or eliminate particle emissions. The issue of diesel emissions will be a major item on the urban transportation agenda in the coming years.
9.3 Reduction Strategies for Persistent Toxic Substances: Life Cycle Management and Pollution Prevention
For some known PTSs, such as the pesticides mirex, aldrin, and dieldrin, the most appropriate emission reduction strategy has been to ban the production and/or use of these substances. Consistent with this approach, the United States and Canada have each enacted regulations governing the registration of new chemicals that require an evaluation of their persistence before their manufacture and/or sale is permitted. There are two groups of PTSs, however, that require different management approaches.
The first group comprises the chemicals and heavy metals that have beneficial or necessary uses. Until effective substitutes of reasonable cost are found, countries may need management strategies that allow selected uses of these substances while ensuring that they are completely retrieved after use for recycling or disposal. This "life cycle management" approach offers the possibility of controlling substances from cradle to grave. For example, PCBs could continue to be used under restricted conditions in electrical equipment, with the intention that they will be fully recovered when the equipment has reached the end of its life and is ready for disposal.
Mercury-containing products such as fluorescent light bulbs also offer an opportunity for life cycle management. Since their use is encouraged in energy conservation programs, there is no overwhelming incentive to ban them and eliminate an environmental benefit. Given the potential risks of uncontrolled disposal of these products in landfills, however, programs must be in place to ensure that they are collected and properly recycled at the end of their life.
The second group of PTSs that may require special management strategies comprises substances that are products of incomplete combustion and trace contaminants that are formed unintentionally in industrial processes. These substances include dioxins, furans, PAHs, and a myriad of polycyclic organics containing oxygen and/or nitrogen in their complex structure. These compounds, even when produced in trace amounts, are extremely difficult and costly to remove or recover from the process. Because their persistence and accumulation in the environment are of great concern, pollution prevention may be the soundest strategy available to deal with them. Under pollution prevention, new or modified technologies to avoid or prevent the formation of these products of incomplete combustion and/or trace contaminants are developed.
Incentives must be provided to encourage industry to actively research and develop pollution prevention technologies for these PTSs. Publicprivate partnerships should be considered when the industry does not have the full capacity to do pollution prevention research and development on its own. The Great Lakes region, for example, has been very active in pursuing pollution prevention initiatives. Some of these are discussed further in a recent IJC report entitled 1995/97 Priorities and Progress under the Great Lakes Water Quality Agreement as well as on the U.S. EPA Great Lakes National Program Office website (www.epa.gov/glnpo/p2).
Recommendation
The Board has recommended to the Commission the development of a uniform standard throughout both countries for sulfur content in gasoline of 30 ppm annual average, with a maximum level of 80 ppm, optimally by the year 2001 but certainly no later than 2005. Subsequently, the Commission made largely the same recommendation to the governments of the United States and Canada.