In this critical review, about 350 publications reported as studies on anthropogenic cycles, mass/material flow analysis, substance flow analysis, stocks and flows analysis, in-use stocks, trade, loss/emissions, recycling, lifespans, industrial metabolism, and material budgets/balances of the elements or alloys were collected by postdoctoral associate Weiqiang Chen and Professor Thomas Graedel of the Yale Center for Industrial Ecology. A total of 1074 individual cycle determinations for 59 elements, 989 static and 85 dynamic, resulted from the review.
Number of derived cycles for the elements most frequently the subject of such analyses.
The number of anthropogenic cycles for different elements at different spatial levels, the features of typical elemental cycles, and the heterogeneities of all these cycles are described in detail. Policy implications and the further work needed for getting more and better elemental cycles are discussed. Summarizing the implications of the existing elemental cycles, Dr. Chen and Professor Graedel concluded that a number of measures are important and feasible for promoting sustainable resource management: (1) promoting the secure supply of elemental resources; (2) reducing the losses of resources back to the environment, especially those that are dissipative losses; (3) promoting the recycling of resources after their end-of-life in the use stage; (4) increasing the lifespans of resources in the in-use stock; (5) avoiding or reducing the toxicity of the elements along their entire life cycles; and (6) exploring potentials of urban mining from in-use stocks and landfill mining from deposited stocks, especially for metals. The link to this critical review is: