National environmental measures can be grouped under six headings.Environmental quality regulations seek to describe a desired state of the environment. They can be specified in terms of an acceptable status for air or water quality, or in terms of maximum concentrations of specific pollutants in the air, water or soil. A modern approach to such regulations, which is responsive to the accumulation of harmful substances in the natural environment, is the concept of “critical loads”: levels of deposition of pollutants below which some elements of the environment are not damaged. Environmental quality regulations can also take the form of population-based measures requiring the protection of certain species that have become threatened or endangered.
đang được dịch, vui lòng đợi..
