Ranking of pharmaceuticals detected in the environment: aggregation and weighting procedures

Pharmaceuticals are omnipresent in waste-water world-wide. Research has shown that many pharmaceuticals are not completely removed during wastewater treatment, and as a result, this has led to their occurrence being reported in waste water treatment plant effluents, rivers and lakes, and more rarely in groundwater and in drinking water. Hence, it is only logical that pharmaceutical residues in the environment and their potential toxic effects have been recognized as one of the emerging research areas in environmental chemistry. A lack of data, especially ecotoxicological and fate data on pharmaceuticals, is evident. The extent to which data are missing should therefore be looked upon in more detail in order to trigger further political steps in performing studies concerning the risk assessment of pharmaceuticals in the environment. In this investigation, we evaluate the data-availability of 16 pharmaceuticals in 17 Internet databases which means we examine a 16 (objects) x 17 (attributes) data-matrix. The consideration of the chosen pharmaceutical in databases is coded 0 = not available, or 1 = available. For the evaluation of the data-matrix, we apply the multi-criteria decision method named METEOR (Method of Evaluation by Order Theory). In contrast to conventional multi-criteria decision aids, like the well-known PROMETHEE, AHP, SMART, ORESTE as well as different versions of ELECTRE, we support the basic consideration of environmetrics: let first the data speak and let us then include subjective preferences in order to get a unique decision. The basis of METEOR is a data-matrix in which the objects are characterized by a set of attributes (indicators). By means of the attributes, a partial order is derived. In the subsequent steps, attributes are aggregated by a weighting procedure, allowing a high degree of involvement of experts, stakeholders and other participants. All conducted approaches show that the data-situation on the chosen test-set of 16 well-known and highly produced pharmaceuticals is far from being satisfactory. For the two well-known pharmaceuticals roxithomycin (antibiotic) and diatrizoate (contrast media), the data-situation is extremely bad, independent of how the weighting is performed. The data-availability for diatrizoate is a little better. The best data coverage is detected for the chemicals carbamazepine, diazepam, ethinyl estradiol, 5-fluorouracil, and phenazone. The issue of pharmaceuticals in the environment and the unavailability of data necessitate much closer communication between science and medical healthcare and politicians in the future.