Thus, for silver, too, the consumption-related share of total emissions is probably close to 100 per cent. The foregoing analysis was entirely historical. But one or two points worth considering for the future emerge clearly. One of them is the fact that several of these toxic heavy metals play a major and increasing role in electronics. Electronic wastes are accumulating in obsolete equipment at an enormous rate in the United States, and all around the world.
Many states already classify such wastes as hazardous.
Leaching - especially that due to increasingly acid rainfall and combustion will mobilize some of these toxic materials. There is, therefore, a strong need for more research on ways and means of closing the materials cycle. Control of Emissions from Metal Melting Operations . American Foundrymen's Society. Ayres, Robert U., Leslie W. Ayres, Joel A. Tarr, and Rolande C. Widgery.