Glossary

a | b | c | g | h | i | m | n | p | q | s | t | u | v | y

Click one of the letters above to advance the page to terms beginning with that letter.

Parts per Billionsearch for term: This is a measure of the concentration of a substance dissolved in another substance. Typically it is used to describe the concentration of a pollutant in water. One part per billion, often abbreviated ppb, is one unit of a substance dissolved in one billion units of another substance. Ppb is equivalent to µg/l.