Understanding and assessing the myriad environmental problems that face society today and devising rational strategies and methods for their control are two of the major international challenges of our time. Critical Reviews in Environmental Science and Technology serves as an international forum for the critical review of current knowledge on the broad range of topics in environmental science. Environmental science is the complex and dynamic interaction of diverse scientific disciplines, including earth and agricultural sciences, chemistry, biology, medicine, and engineering, and the development of new disciplines such as environmental toxicology and risk assessment.