Current and Persistent Environmental Challenges
There has been substantial progress over the last few decades in lessening many of the obvious environmental problems, such as black smoke coming from smokestacks, stench arising from rivers, and fish kills in US lakes. But the challenges associated with environmental protection today are complex, affected by many interacting factors, and no less daunting. They are on various spatial scales, may unfold over long temporal scales, and may have global implications. The problems are sometimes called “wicked problems”, and are often characterized by being difficult to define, unstable, and socially complex; having no clear solution or end point; and extending beyond the understanding of one discipline or the responsibility of one organization. Although the committee cannot predict with certainty what new environmental problems EPA will face in the next 10 years or more, it can identify some of the common drivers and common characteristics of problems that are likely to occur. Some key features of persistent and future environmental challenges are complex feedback loops; the need to understand the effects of low-level exposures to numerous stressors as opposed to high-level exposures to individual stressors; the need to understand social, economic, and environmental drivers; and the need for systems thinking to devise optimal solutions.
The following are a few examples of persistent and emerging environmental challenges that pertain to EPA and its mission.
Chemical Exposures, Human Health, and the Environment. New chemicals continue to be created and enter the environment. Understanding what chemicals are in the environment, concentrations at which people are being exposed, pathways through which they are being exposed, and how different chemicals and stressors interact with one another encompasses some of the persistent challenges that EPA faces. Another challenge is to continue to elucidate the many factors that can modify the health effects of exposure to chemicals and other stressors. The chemical, biologic, and physical characteristics of an agent, the genetic and behavioral attributes of a host, and the physical and social characteristics of the environment are all influential.
Air Pollution and Climate Change. Emissions of major air pollutants were dramatically reduced from 1990 to 2010. Much of that success resulted from the establishment and enforcement of the Clean Air Act. Despite substantial progress, the agency’s efforts to improve air quality continue to have high priority because the economic costs that air pollution imposes on society remain high. The Clean Air Act and other statutory mandates give rise to the need for improved scientific and technical information on health exposures and effects, on ecologic exposures and effects, on ambient and emission monitoring techniques, on atmospheric chemistry and physics, and on pollution-prevention and emission-control methods for hundreds of pollutants present in both indoor and outdoor environments. EPA also faces the critical challenge of helping to find efficient and effective approaches to mitigating climate change and improving