Ricerc@Sapienza

The aims of the present studywere to establish reference values useful in monitoring Lithium(Li) treatment and
to trace environmental Li exposure profiles in paediatric age.
A cross-sectional studywas conducted on a group of healthy Italian children aged 5–11. Data on possible predictors
were assessed through a questionnaire, and Li levels in morning and evening urinary samples were determined
by ICP-MS technique.
The reference intervals for the evening and morning samples were respectively 3.8–51.9 μg L−1 or
5.6–60.6 μg g−1 creatinine and 4.8–71.7 μg L−1 or 4.8–73.2 μg g−1 creatinine. Urinary Li levels showed
a significantly inverse correlation with age and a positive correlation with urinary creatinine in both
the evening and morning samples. No other studied variables influenced Li urinary excretion.
These results, obtained using a readily available matrix as urine, can be useful for both environmental research
and Li treatment monitoring.