So 75 100 125 Iso 175 200

Time, seconds Fig. 5. Hydrogen production from the APOR during cold-start.

A POUND OF PREVENTION: AIR POLLUTION AND THE FUEL CELL

Barry L. Johnson Agency for Toxic Substances and Disease Registry Atlanta, GA

and Robert Rose Fuel Cells 2000 Washington, DC

The expanded use of fuel cells jn transportation and power generation is an exciting proposition for public health officials because of the potential of this technology to help reduce air pollution levels around the globe. Such work is about prevention — prevention of air emissions of hazardous substances. Prevention is a key concept in public health. An example is quarantine, which aims to prevent the spread of a disease-causing organism. In the environmental arena, prevention includes cessation of pollution.

Air pollution prevention policies also have a practical impact. Sooner or later ideas on technology, especially new technology, must be sold to polity makers, legislators, and eventually the public. Advocating technologies that will improve human health and welfare can be an effective marketing strategy.

We believe that the health and environmental potential of fuel cells is substantially underestimated by most analysts. While our focus is on the motor vehicle, an analysis similar to the one that follows is possible for stationary power generation, where "nontraditionaT pollutants such as mercury are emerging as substantial public health concerns.

The air pollution story developed with considerable uncertainly about whether health effects might manifest There were plenty of doubters — especially in the automobile industry, which argued that their emissions could not be a problem to human health, or could be ameliorated, by taking advantage of the dilution effect of ambient air. Of course, these arguments were advanced in the mid-1960s, when there were only 90 million cars and trucks in the U.S. Today, there are 200 million, and we drive 2.3 trillion miles every single day. Given the trend, the new fuel cell technology appears to us to be the savior not only of our air quality but of our auto industry.

The argument of regulated industries can be summarized as The Solution to Pollution is Dilution. This fallacious maxim has had incalculable adverse consequences. Pollutants are still being dumped into waterways, the air, and soil. We and the other species on the planet continue to suffer the consequences. Our maxim must change: The Solution to Pollution is Diminution.

THE CAR CONUNDRUM. Access to personal transportation has characterized much of human endeavor. Today, even in the remotest comers of the world, internal combustion engines provide unprecedented personal mobility and demand continues to increase. In 1965 there were-178 million vehicles worldwide. Today, there are well more than 600 million; nearly 50 million new vehicles are produced every year. From the public health perspective, that means 50 million new pollution sources, and an exploding infrastructure that adds additional poisons to the environment A new car built to U.S. emission standards will emit a ton of pollution during its life. An. uncontrolled car will emit two to three times that Many diseases or conditions involving various organ systems are affected by motor vehicle related pollution.

1. "Criteria" pollutants (see chart). While many inhaled pollutants have direct respiratory consequences, others affect the heart or nervous system. Pollutant exposure may alter normal activities and life-style. Within the respiratory tract itself, pollutants derived from motor vehicle emissions have the potential to induce bronchoconstriction, reduce pulmonary function, increase susceptibility to respiratory infections, and contribute to tumor formation. The health significance of short-term effects is not well understood, and the contribution of repeated, reversible acute effects to chronic damage is not known. Low-level exposures may initiate an inflammatory process leading, for example, to production of excess connective tissue and ultimately to the development of chronic pulmonary disease.

Under the Clean Air Act of 1970, EPA has set national air quality standards for the criteria pollutants and established cleanup programs that have made the worst pollution days better, and accommodated substantial economic growth. But problems remain, and EPA's Clean Air Science Advisoiy Committee has recommended, based on the latest health studies, that the standards be stronger for ozone smog and fine particulate. Regulated industry is resisting, arguing that the air is "clean enough." Yet approximately 62 million people lived in counties where pollution levels exceeded the national standards for at least one of the sue principal pollutants in 1994. That means one of four Americans experienced officially "unhealthful" levels of one or more air pollutants. At the most restrictive end of the CASAC recommended range, closer to 200 million would live in areas classified as unhealthful for ozone smog.

Urban Air Pollutant and Air Quality Standards

Pollutant

Sensitive Population

Effects

Prim. NAAQS

Aver. Time

Ozone (ppm)

Exercising children and young adults

Respiratory symptoms, lung function decrement, decreased exercise capacity

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