Perchlorate: water and infant formulae contamination in France and risk assessment in infants.

Perchlorate ions ClO4(-), known to inhibit competitively the uptake of iodine by the thyroid, have been detected in drinking water in France as well as in infant formulae. A tolerable daily intake (TDI) has been established at 0.7 µg kg(-1) bw day(-1) based on the inhibition of iodine uptake. Due to this mechanism of action, the iodine status could strongly influence the biological effect of perchlorate. Perchlorate concentrations in water and infant formulae were measured and the exposure of children under 6 months of age calculated. It appeared that the TDI could be exceeded in some children. As the iodine status is not optimal within the entire French population, there appears to be a need to clarify the sources of perchlorate ultimately to decrease exposure.

Ecological risk assessment of the presence of pharmaceutical residues in a French national water survey.

In this study, we focused on the list of 33 chemicals that was established through a French national prioritisation strategy. Assessing the potential risks to the environment was a step-wise procedure: (i) we determined the Predicted Environmental Concentration (PEC) of all molecules measured in the national survey based on the highest recommended dose used, (ii) we used the Measured Environmental Concentration (MEC) and the Predicted No-Effect Concentration (PNEC) to establish the Risk Quotient (RQ) based on either a PEC/PNEC (estimated risk) or MEC/PNEC (real risk) ratio. The risk assessment was performed using a binary ecological classification suggesting that appreciable risk is likely (RQ⩾1). Of the 15 molecules quantified in the survey, 12 had a PEC higher than the action limit value of 0.01µg/L. According to the EU Guideline, environmental risk was estimated as likely for the following five compounds: acetaminophen (RQ=1.6), ibuprofen (RQ=600), diclofenac (RQ=15), oxazepam (RQ=2.1) and carbamazepine (RQ=3.2). Only ibuprofen was identified as posing real environmental risk based on its MEC (RQ=1.9).