Paper can only be recycled 3 times, because the fibers get shorter and weaker each time the paper is recycled.
Bugs give clean sites a glowing recommendation
Bugs give clean sites a glowing recommendation Scottish scientists have developed a new biosensor
which easily indicates the presence of biologically toxic chemicals
in soil through changes in its glowing activity. The biosensor
consists of several varieties of soil bacteria which have been
genetically modified to glow when they are healthy, and will stop
glowing when they are weakened or die due to chemicals in the
soil. 4 DECEMBER 1999, P. 20