Air Quality & Public Health

Internal combustion diesel engines power most transportation of goods in the North America today. These machines are used to power trucks, railroad locomotives, and inland barge traffic. Unfortunately, diesel emissions clearly compromise human health. Their adverse consequences can be traced to two principal diesel pollutants—particulates, small particles of soot—and nitrous-oxides. Nitrous oxides react in the presence of sunlight to form low-level ozone, commonly known as smog.

The American Lung Association states that children, teenagers and the elderly are particularly at risk for health consequences from particle and ozone pollution, but all exposed people are at risk. “Busy highways are high risk zones. Pollution from heavy highway traffic contributes to higher risks for heart attacks, allergies, premature births, and the deaths of infants around the time they are born.” (See the research. [1])

Asthma, bronchitis, lung infections, cardiac arrhythmia,and reduced lung function are associated with both brief and chronic exposure to diesel emissions. Hospitalization for and pre-mature death from respiratory and cardiovascular causes, including stroke, mortality in infants and young children, heart attacks, lung and blood cancers may also result [2].

The easiest, cheapest, and surest way to reduce ozone and particulate pollution and consequently improve air quality and public health is to remove diesel engines from our environment while still delivering the same level of mobility. One electrically powered locomotive on the Steel Interstate will move people or products virtually pollution-free, substituting renewable electric power for dozens of truck or automobile engines. [Citation coming.]

Huge fuel savings are possible with an electrified North American Steel Interstate System. [Millennium Inst. Study, see first pdf in “Related Resource” column on right] A half billion barrel annual oil savings at the cost of less than 1% added electric generation constitutes a paradigm shift.

Think, too, about where the emissions are generated. First, there would be huge emission reductions from the elimination of tens of millions of small, mobile diesel and gasoline engine point sources. Power generation would be transferred to minor increases at electric generating stations. Optimally, this power would come from renewable energy resources where there is virtually no emission impact. But even where that is not immediately achievable, there is a large and identifiable benefit from concentrating emissions at power plants where most of such emissions can be captured and treated at the origin. Attempting to clean up individually countless internal combustion engines is costly and challenging by comparison.

New Environmental Protection Agency (EPA) diesel regulations are estimated to reduce diesel particle pollution by up to 95%. Some what less dramatic reductions in smog-causing nitrous-oxide emissions are resulting from new EPA rules. Transitioning from diesel to electric locomotives will markedly reduce particle and nitrous oxide pollution from locomotives and as more freight and whole trucks move by rail these pollutants will be reduced further from the North American transportation sector.

However, both diesel particulate and nitrous oxide emissions continue to be a very significant health hazard, primarily because of continued operation of older diesel trucks and locomotives. Railroad locomotives are on a schedule to be replaced or overhauled with new pollution control equipment. However, older high-emitting trucks may be in use for 20 more years or more [3]. A highly interconnected Steel Interstate would retire many of these marginal, older, heavily polluting trucks.

Since problem pollutants come from burning fuel, it’s highly significant that huge fuel savings are possible with an electrified Steel Interstate System. A 2009 Millennium Institute study, [see first pdf in “Related Resource” column on right] concluded that the Steel Interstate System, coupled with a large investment in urban transit, could save the U.S.A. half a billion barrels of oil annually --a 22 per cent cut in total U.S. oil consumption and all it’s attendant hazardous pollution. This reduction could come at a cost of less than 1% added electric generation.

One of the principal authors of this Millennium study asserts that a Steel Interstate-type U.S. system alone could, if able to deliver 85% of all freight ton-miles now shipped by truck, cut 12% of all petroleum consumed in the U.S. for all purposes [4]. The North American Steel Interstate Coalition sees the Steel Interstate as certainly capable of carrying at least 60% of all truck ton-miles, which extrapolates to an 8.5% savings of U.S. oil use. Such savings dwarfs other means of reducing emissions. The required electric power could come from renewable sources with virtually no polluting emissions.

Ozone

Commonly known as smog, ozone pollution in the North America has noxious and widespread effects. The American Lung Association has a comprehensive description of ozone pollution: What it is? What the health affects of ozone exposure are? Why ozone is harmful? And how serious is that risk? For example:

• Ozone reacts chemically ("oxidizes") with internal body tissues, such as those in the lung. Think of it as "sunburn" on the lungs. Ozone irritates and inflames the respiratory system at levels frequently found across the nation during the summer months…Children who grow up in areas of high ozone pollution may never develop their full lung capacity as adults. That can put them at greater risk of lung disease throughout their lives [5].

In a study of 95 U.S. cities, researchers determined, “An increase of 10 parts per billion (ppb) in weekly ozone levels was associated with a 0.52 percent daily increase in deaths the following week. The rate of daily cardiovascular and respiratory deaths increased 0.64 percent with each 10 ppb increase of ozone [6].”

Source: U.S. EPA

EPA’s proposed low-level ozone standards would realize direct health benefits from adopting a 0.070 parts per million (ppm) primary standard. These improvements would include avoidance of 1,500 to 4,300 premature deaths annually in 2020. The more stringent 0.060 ppm standard would avoid 4,000 to 12,000 premature deaths annually. Other advantages by 2020 would include preventing the following, annually:

• 880 to 2,200 cases of chronic bronchitis
• 2,200 to 5,300 nonfatal heart attacks
• 6,700 to 21,000 hospital and emergency room visits
• 2,100 to 5,300 cases of acute bronchitis
• 44,000 to 111,000 cases of upper and lower respiratory symptoms
• 23,000 to 58,000 cases of aggravated asthma
• 770,000 to 2.5 million days when people miss work or school
• 2.6 million to 8.1 million days when people must restrict their activities [7].

Unfortunately, the public is ill-informed about the extent of their PM exposure. Only 675 of the U.S.’s 3,000 counties have ozone monitoring stations [8]. There are only 830 PM monitoring stations across the U.S., including muliple sites in some counties [9]. The current ozone monitoring network is clearly inadequate to detect violations of a more stringent standard. Rural areas are largely left out of the monitoring network, which doesn’t account for heavy diesel truck use and idling at truck stops, rest areas, and terminals frequently situated along rural highways.

A cooperative North American policy to divert diesel-based, inter-city truck traffic to green energy-powered electrified rail transport will result in huge reductions in ozone, particularly in those areas where large amounts of ozone-forming pollutants arise from heavy highway truck traffic.

Diesel Particulate Matter (PM)

The American Lung Association has a comprehensive description of particle pollution: What it is? What the health affects of PM are? Who is at risk? And how serious is that risk?

First and foremost, short-term exposure to particle pollution can kill. Peaks or spikes in particle pollution can last for hours to days. Deaths can occur on the very day that particle levels are high, or within one to two months afterward. Particle pollution does not just make people die a few days earlier than they might otherwise—these are deaths that would not have occurred if the air were cleaner [10].

Researchers from Harvard University recently tripled the estimated risk of premature death [from particle pollution] following a review of the newer evidence from fine particle monitors (PM_2.5) in 27 US cities [11].  As mentioned earlier, scientists at the California Air Resources Board also tripled their estimate of the number of deaths occurring each year from particle pollution. They now put the range between 5,600 to 32,000 deaths a year in that state alone [12].

Additional health impacts can result from exposure to secondary diesel PM that is formed in the atmosphere from oxides of nitrogen, emitted from diesel engine exhaust. Atmospheric chemical processes can form very fine particles from diesel exhaust. When inhaled these ultra-fine particles can move deep into lung passage ways.

Note that the non-attainment areas in the following map reflect non-attainment for current PM standards. When these standards were adopted in 2006, EPA scientists called the standards insufficient to protect public health. In February, 2009, the United States Court of Appeals for the District of Columbia Circuit ordered the EPA to reconsider both fine and coarse PM standards. More stringent standards will likely be issued soon [13].

Increased health risk is measurably correlated to increased PM exposure, “Each 10 microgram/cubic meter increase in PM leads to 8 percent increased risk of lung cancer deaths, a 6 percent increased risk of cardiopulmonary mortality/heart attacks, and a 4 percent increased risk of death from general causes [14].”

Diesel engine emissions cause most of California's known outdoor air pollutant cancer risk. Californians average only about 6% of their time the road, yet 30 to 55% of diesel PM exposure occurs in vehicles [15]. Based on potential to cause cancer, premature death, and other health problems California identified diesel PM as a toxic air contaminant. Children whose lungs are still developing and the elderly who may have other serious health problems are most at risk. California estimates that every year diesel PM contributes to 3,500 premature deaths and thousands of hospital admissions, asthma attacks and other respiratory symptoms, and lost workdays [16].

In America, PM contributes to premature death from heart and/or lung diseases, based on studies of over 500,000 people [17], and independent reanalysis requested by industry and the U.S. Congress [18]. Comparing cities with highest and lowest PM levels, average life expectancy declined about 1.5 years [19]. This translates to a loss of about 14 years of life for people who died from diseases associated with PM exposure [20].

“By age 18, children exposed to higher levels of…fossil fuel combustion, especially diesel, are five times more likely (7.9% versus 1.6%) to have underdeveloped lungs (80% of normal, equivalent to having aged over 20 additional years) compared to teenagers living in communities with lower pollutant levels, and will likely never recover [21].”

“Intervention” studies report significant reduction in adverse health incidence among children after either removal or reduction of a PM emission source. For example, the Southern California Children's Health Study reported improved lung function growth rates for young children who relocated from a high PM area to a lower PM area [22].

Children’s respiratory and immune systems are still developing, and they breathe as much as 50% more air, by body weight, than adults [23]. They are more likely to suffer from asthma due to the aspiration of diesel soot. Asthma is the leading chronic disease among children, as well as the greatest cause of school absenteeism [24].

Elderly and sick people also are disproportionately hurt by diesel engine emissions. Poor cardiopulmonary health and weakened immune systems make these people more susceptible to harm from diesel soot. People in the trucking industry and those living near major highways, truck stops, truck or rail terminals or anywhere that diesel truck or locomotive use is concentrated are more affected than those in other, more isolated areas.

California estimates that diesel PM contributes to 3,500 deaths (ranging from 1,000 to 6,400) annually [25]. Specific studies that link motor vehicle-related PM exposure to premature death include:

• Elderly people living near major roads had almost double the risk of dying from cardiopulmonary causes [26].
• PM from motor vehicles was linked to increased mortality [27].
• Fine PM (PM2.5, particles measuring 2.5 micrometers across, less than 1/3 the width of a human hair) from vehicle sources accounted for three times the mortality as did PM2.5 from coal combustion [28].

PM is also related to hospital admissions and emergency room visits for asthma, cardiopulmonary causes [29], and lost work days [30]. The California Air Resources Board estimates that there are “thousands of hospital admissions for cardiopulmonary causes, emergency room visits, asthma attacks, and millions of lost work days each year in California due to PM [31].”

Californians average only about 6% of their time the road, yet 30 to 55% of diesel PM exposure occurs in vehicles [32]. The Environmental Defense fund claims, “Diesel exhaust contains toxic chemicals that together with diesel particulate matter pose a cancer risk greater than that of any other air pollutant [33].”

Diesel Engine Idling and Particle Pollution

Over-the-road trucks typically idle for an average of six hours per day [34]. Trucks idling at truck stops and rest areas form atmospheric pools of highly-concentrated pollutants that directly affect nearby residents, workers, and school children.

Diesel engines do not operate as efficiently at idle or at low speeds as they do under normal highway operating conditions.Chemical analysis confirms more pollutants in truck emissions produced at lower speeds and at cooler idle. The particles emitted contained more potential cancer-causing pollutants; specifically, more polycyclic aromatic hydrocarbons (PAHs). At high engine operating conditions, the particles consist mostly of carbon in the form of graphite. When diesel trucks are driven on the highway, they principally produce graphitic particles, but in the downtown areas of major cities or while idling, diesel engines produce particles containing both graphitic and hydrocarbon components, including possibly harmful PAHs [35].

Conclusion

The Steel Interstate System will reduce public health damage from ozone and particle pollution by dramatically reducing the amount of oil burned to move products and people around North America. Further, as this system is electrified and that electric power is derived from renewable sources, which the Steel Interstate System will help to transmit, the Steel Interstate System will operate with virtually no contribution to ozone or particulate pollution, except where trucks interface with rail at terminals.

Citations