A class of chemicals typically
formed by burning and common in
the environment. PAHs are also
common to petroleum products and
oil. Although most of these
compounds are harmless or mildly
toxic, some are carcinogenic.
The area below the limnetic zone
where light does not penetrate.
This area roughly corresponds to
the hypolimnion layer of water and
is home to organisms that break
down or consume organic matter.
Material that still has useful
physical or chemical properties
after serving its original purpose
and can, therefore, be reused or
remanufactured into additional
products. Plastic, paper, glass,
used oil, tin and aluminum cans
are examples of recyclable
materials.
The process of collecting
materials from the waste stream
and separating them by type,
remaking them into new products,
and marketing and reusing the
materials as new products.