Search

Due to the current analytical processes that are not able to measure all the pharmaceutical molecules and to the high costs and the consumption of time to sample and analyze PhACs, models to calculate Predicted Environmental Concentrations (PECs) have been developed. However a comparison between MECs and PECs, taking into account the methods of calculations and peculiarly the parameters included in the calculation (consumption data, pharmacokinetic parameters, elimination rate in STPs and in the environment), is necessary to assess the validity of PECs. MEC variations of sixteen target PhACs [acetaminophen (ACE), amlodipine (AML), atenolol (ATE), caffeine (CAF), carbamazepine (CAR), doxycycline (DOX), epoxycarbamazepine (EPO), fluvoxamine (FLU), furosemide (FUR), hydrochlorothiazide (HYD), ifosfamide (IFO), losartan (LOS), pravastatin (PRA), progesterone (PROG), ramipril (RAM), trimetazidine (TRI)] have been evaluated during one hydrological cycle, from October 2011 to October 2012 and compared to PECs calculated by using an adaptation of the models proposed by Heberer and Feldmann (2005) and EMEA (2006). Comparison of PECs and MECS has been achieved for six molecules: ATE, CAR, DOX, FUR, HYD and PRA. DOX, FUR and HYD present differences between PECs and MECs on an annual basis but their temporal evolutions follow the same trends. PEC evaluation for these PhACs could then be possible but need some adjustments of consumption patterns, pharmacokinetic parameters and/or mechanisms of (bio)degradation. ATE, CAR and PRA are well modeled; PECs can then be used as reliable estimation of concentrations without any reserve. [ABSTRACT FROM AUTHOR]

Abstract: In order to investigate the role of local contribution versus long-range transport in the rainwater chemistry at a site in the North-western Mediterranean area, we collected 90 daily wet samples, 75 dry samples (corresponding to bulk sampling during dry periods) and 102 sequential wet sub-samples from October 1997 to March 1999. Major ions were analyzed (Mg2+, Ca2+, Na+, K+, Cl−, SO4 2−, NO3 −, NH4 +, HCO3 −) along with the determination of pH and electrical conductivity. To discriminate the fraction of components supplied by long- and medium-range transport from that derived from local scavenging, a classification of precipitation chemistry according to air masses back trajectories and sources has been established. Three different origins were identified: (1) a Western one associated with high amount of rainfall and an equivalent contribution of terrestrial, marine and anthropogenic components, (2) a Northern and North-eastern origin characterized by low rainfall heights and a high load in anthropogenic and terrestrial components, (3) a Southern origin which presented the highest concentration in sea-salt components and a high participation of anthropogenic components. Determination of the local contribution has been achieved through the characterization of dry deposition rates and the investigation of the evolution of rain chemistry during events. As only 21 to 32% of the total concentration is removed in the first fraction, it appeared that the below-cloud scavenging process does not dominate the removal of atmospheric components in the region. The evolution of the rain chemistry during an event is perturbed by increases of concentrations that could be due either to long-range inputs (of humid air parcels coming from the near Mediterranean Sea or occurrence of Saharan dust) or to the scavenging of local sources of pollutants and terrestrial material. [Copyright &y& Elsevier]