Nanomaterials May Have Large Environmental Footprint

Hatice Şengül and colleagues at the University of Illinois at Chicago assert that strict material purity requirements, lower tolerances for defects and lower yields of manufacturing processes may lead to greater environmental burdens than those associated with conventional manufacturing. In a separate study of carbon nanofiber production, Vikas Khanna and colleagues at Ohio State University found, for example, that the life-cycle environmental impacts may be as much as 100 times greater per unit of weight than those of traditional materials, potentially offsetting some of the environmental benefits of the small size of nanomaterials.

Materials engineered at dimensions of 1 to 100 nanometers¬ (1 to100 billionths of a meter) ¬exhibit novel physical, chemical and biological characteristics, opening possibilities for stunning innovations in medicine, manufacturing and a host of other sectors of the economy.

Because small quantities of nanomaterials can accomplish the tasks of much larger amounts of conventional materials, the expectation has been that nanomaterials will lower energy and resource use and the pollution that accompanies them. The possibility of constructing miniature devices atom-by-atom has also given rise to expectations that precision in nanomanufacturing will lead to less waste and cleaner processes.

"Research in this issue reveals the potential of environmental impacts from nanomanufacturing to offset the benefits of using lighter nanomaterials," says Gus Speth, dean of the Yale School of Forestry & Environmental Studies.

"To date, most attention has focused on the possible toxic effects of exposure to nanoparticles¬ and appropriately so. But considerations of pollution and energy use arising from the production technologies used to make nanomaterials need attention as well."