1 ppb means one part in 1 billion. It can be converted into [tex]\mu g/kg[/tex] as follows:
[tex]1 ppb=1\mu g/kg[/tex]
Also, 1 L is equal to 1 kg because density of water is 1 kg/L.
Thus,
[tex]1 ppb=1\mu g/L[/tex]
The arsenic level in groundwater in Bangladesh ranges from [tex]200 \mu g/L[/tex] to [tex]500 \mu g/L[/tex]. This can be converted into ppb as follows:
[tex]200\mu g/L=200 ppb[/tex]
and,
[tex]500\mu g/L=500 ppb[/tex]
Therefore, the range in ppb is 200-500 ppb.
