The United Nations Declaration of The Human Environment in 1972 in Stockholm declares 26 principles concerning the preservation and enhancement of the human environment. Among them, Principle 23 declares that "Without prejudice to such criteria as may be agreed upon by the international community, or to standards which will have to be determined nationally, it will be essential in all cases to consider the systems of values prevailing in each country, and the extent of the applicability of standards which are valid for the most advanced countries but which may be inappropriate and of unwarranted social cost for the developing countries".