|Resumen: ||In the last years pharmaceutical and personal care products (PPCPs) have been found at different level of concentrations in all environmental compartment (air, water and soil), and many of their impacts are still unknown or they are under analysis. One tool used for estimated the potential impact of PPCPs in the environment is the life cycle assessment (LCA). PPCPs are being increasingly included in LCAs since they have evidenced ecological and human adverse effects and due to their presence in different environmental compartments, wastewater facilities and industry. In environmental LCAs, CFs (alternatively referred to as equivalency factors) are used to determine the relative importance of a substance to toxicity related impact categories, such as human toxicity and freshwater ecotoxicity (Huijbregts et al. 2005a). In this sense, the USEtoxTM model is a powerful tool to calculate CFs. It is an environmental model for characterization of human and ecotoxicological impacts in life cycle impact assessment (LCIA) and comparative risk assessment (Huijbregts et al., 2010a).
Despite the large number of substances which have been considered in the USEtoxTM database (more than 3000 in the USEtoxTM organic database 1.01) a small amount of PPCPs have been considered (approximately less than 2% of the organic database corresponds to this group of compounds). Accordingly, the CFs of many PPCPs have not been calculated. Therefore, the main goal of this research was to estimate CFs of 27 PPCPs widely used worldwide for incorporating these values in LCIA studies or to generate impact score rankings. USEtoxTM software was used for estimating CFs. Methodological procedure and main equations of the concept and model of USEtoxTM of human toxicity and ecotoxicity are widely explained in the literature (Huijbregts et al. (2005b); Huijbregts et al. (2010a); Huijbregts et al. (2010b); Rosenbaum et al. (2008)). An impact score ranking was done for 49 PPCPs using the new CFs calculated and the CFs already available and besides the data of PPCPs occurrence in the environment in Spain from a previously study (Ortiz et al., 2013). Physicochemical properties, degradation rates, bioaccumulation, ecotoxicity and human health effects were collected from experimental data, recognized databases or estimated by EPI SuiteTM. PPCPs from 14 different therapeutic classes have been considered in this study: analgesic/antipyretic, Angiotensin converting enzyme inhibitor, angiotensin receptor blockers, antibiotics, antidepressants, antiepileptics, anxiolytics, blood lipid regulators, cytostatics/cancer therapeutic, H2 blocker, hormones, Platelet inhibitor, non-steroidal anti-inflammatory drugs (NSAIDs)/antirreumatics, X-ray contrast media and PCPs. The input parameters that must be supplied by the user for the USEtoxTM program were: molecular weight (MW), partition coefficient between octanol and water (Kow), partition coefficient between organic carbon and water (Koc), Henry law coefficient at 25ºC (KH), vapor pressure at 25ºC (Pvap), solubility at 25ºC (Sol), degradation rate in air (KdegA), degradation rate in water (KdegW), bioaccumulation factor of the chemical (BAF), water ecotoxicity (chronic and acute) and human carcinogenic and non-carcinogenic effects.
There is still lack of experimental data of carcinogenic and non-carcinogenic effects of PPCPs to predict these effects on humans. In ecotoxicology more efforts should be made to know chronic effects and PPCPs mixture effects on different organisms and trophic levels. With these values, the CFs calculation will be more adjusted to reality.
Emission to continental freshwater compartment showed the highest CFs for human effects (ranging on 10-9 to 10-3), following by air (10-9 to 10-5), soil (10-11 to 10-5) and sea water (10-12 to 10-4). These results indicate the relative order of importance of different PPCP emissions and to what grade (magnitude) can affect the human health, being the drug emission to continental freshwater the most important compartment. CFs of the affectation of freshwater aquatic environments were the highest from emission to continental freshwater (between 1 to 104) due to the direct contact between the source of emission and the compartment affected, followed by soil (among 10-1 to 104), air (among 10-2 to 104) and the lowest were continental sea water CFs (among 10-28 to 10-3). CFs of continental sea water as emission source are the lowest, probably by the difficulty in the inter-compartment transfer (continental sea water to continental fresh water) and therefore, the low bioavailability of the compounds in fresh water from sea water.
Freshwater aquatic ecotoxicological CFs are much higher than human toxicity CFs due to the low tolerance of aquatic organisms to these compounds and the persistence of them in this media, which involves that ecological impact of PPCPs in aquatic environment is a matter of urgent attention.
PPCPs with the highest impact scores are hormones, antidepressants, fragrances, antibiotics, angiotensin receptor blockers and blood lipid regulators, which have been already found in other ranking scores. In this study most antibiotics are located in the top 20 of the ecotoxicity impact score and for human toxicity impact score azithromycin and levofloxacin are in the top 10.
Although it is not surprising that some of the compounds studied in this research occupy the top ranking (by previous researches) even their CFs was not known. The estimation of new CFs should be continued, either for compounds that are already marketed as for the new ones. These results, not available until now, are useful to do better LCIAs incorporating these pollutants in these studies or for assessing single hazard/risk environmental impact assessments.|