▁to ▁ 2 ▁August ▁ 1 9 9 1 , ▁found ▁that ▁the ▁average ▁cost ▁per ▁ton ▁r anged ▁from ▁$ 4 0 ▁to ▁$ 6 0 ▁while ▁a ▁US GS ▁report ▁shows ▁that ▁the ▁cost ▁per ▁ton ▁of ▁raw ▁sil ica ▁sand ▁from ▁years ▁ 1 9 9 3 ▁to ▁ 1 9 9 7 ▁fell ▁between ▁$ 1 7 . 3 3 ▁and ▁$ 1 8 . 1 0 . ▁ ▁Compar ing ▁the ▁market ▁cost ▁of ▁rec y cl able ▁material ▁with ▁the ▁cost ▁of ▁new ▁raw ▁materials ▁ign ores ▁economic ▁external ities — the ▁costs ▁that ▁are ▁currently ▁not ▁counted ▁by ▁the ▁market . ▁Creating ▁a ▁new ▁piece ▁of ▁pl astic , ▁for ▁instance , ▁may ▁cause ▁more ▁poll ution ▁and ▁be ▁less ▁sust ain able ▁than ▁rec y cling ▁a ▁similar ▁piece ▁of ▁pl astic , ▁but ▁these ▁factors ▁will ▁not ▁be ▁counted ▁in ▁market ▁cost . ▁A ▁life ▁cycle ▁assess ment ▁can ▁be ▁used ▁to ▁determine ▁the ▁levels ▁of ▁external ities ▁and ▁decide ▁whether ▁the ▁rec y cling ▁may ▁be ▁worth while ▁despite ▁unf avor able ▁market ▁costs . ▁Alternatively , ▁legal ▁means ▁( such ▁as ▁a ▁carbon ▁tax ) ▁can ▁be ▁used ▁to ▁bring ▁external ities ▁into ▁the ▁market , ▁so ▁that ▁the ▁market ▁cost ▁of ▁the ▁material ▁becomes ▁close ▁to ▁the ▁true ▁cost . ▁ ▁Working ▁conditions ▁▁ ▁The ▁rec y cling ▁of ▁waste ▁elect rical ▁and ▁electronic ▁equipment ▁in ▁India ▁and ▁China ▁generates ▁a ▁significant ▁amount ▁of ▁poll ution . ▁Inform al ▁rec y