Cumulative concentration of ephedrines has been reported at higher concentrations during winter months (Kasprzyk-Hordern and Baker, 2012a). Furthermore, a high contribution of the enantiomer 1S,2S(þ)-pseudoephedrine during winter is consistent with increased usage of over-the-counter-medication used to treat symptoms of cold (Kasprzyk-Hordern and Baker, 2012b).