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APPENDIX 4
Conversion Factors used for Lead Concentrations
Concentrations of lead in tissues can be measured in different units. This section is provided to help the reader compare studies.
Unit Symbol is equivalent to Conversion factor
parts per million ppm mg/kg & µg/g 1
milligrams per kilogram mg/kg µg/g & ppm 1
micro grams per gram µg/g mg/kg & ppm 1
micromols per kilogram µmol/kg ppm 207.2 X 1000 4.83
micromols per kilogram µmol/kg µmol/l 1
micromols per litre µmol/L µmol/dl X 10 10
Exact conversions
One decilitre = 100 mls
To convert mols to grams multiply by 207.2
(i.e. 1 mol = 207.2 g)
To convert grams to mols divide by 207.2
(i.e. 1 g = 0.00483 mols)
Micro (µ) = millionth, milli (m) = thousandth and
deci (d) = hundredth
ppm=µg/g=mg/kg
Approximate conversions
One litre is approximately equal to 1kg for blood (1.05 kg but this
is usually rounded up to 1 kg).
To convert soft tissue dry weight lead concentration to wet
weight lead concentration divide by 3.1, and to convert soft
tissue wet weight lead concentration to dry weight lead
concentration multiply by 3.1.
To convert bone dry weight lead concentration to wet weight
lead concentration divide by 4, and to convert bone wet
weight lead concentration to dry weight lead concentration
multiply by 4.