PW08 Ecotoxicity and Environmental Chemistry of Antibiotics
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW133) (Q)SAR based hazard prioritization of antibiotics.
Sanderson, H1, Johnson, D1, Wilson, C1, Brain, R1, Solomon, K1, 1 University of Guelph, Centre for Toxicology, Guelph, Ontario, Canada
ABSTRACT- Continued exponential growth in the human population and shifts in demographic structure in developed countries, combined with the increasing wastewater production, use of sewage sludge and manure on agricultural farmland and the occurrence of antibiotics in the environment are connected issues. However, the risks associated with occurrence of antibiotics and other pharmaceuticals in water resources are widely unknown. The aim of this research is to characterize and present a hazard prioritization tool for pharmaceuticals in the environment. In light of the current lack of ecotoxicological, use, and fate data we scanned close to all common antibiotics (n = 225) compounds for ecotoxicological properties and sorption to sludge by Structure Activity-Relationship (SAR) analyses using software provided by the Syracuse Research Corporation for preliminary hazard assessment. We ranked the antibiotics according to predicted hazards and present an overview useable for prioritization purposes. Finally, we increased our resolution and ranked more than 50 pharmaceutical classes (n > 3200) in terms of risks to the aquatic environment and thus characterize the relative potential hazards of pharmaceuticals in the environment based on intrinsic toxicity. 16% of the compound classes had average HQ > 1 before application of assessment factor. In conclusion, the long-term effects of subtle and chronic changes, mixtures, additive or synergistic effects and effects on other endpoints e.g. bacteria resistance, reproduction, metabolism, behavior etc. are still uncertain and requires expert judgment. Thus, preliminary probabilistic hazard screenings indicates that the ecotoxicological and environmental regulatory challenges of pharmaceuticals is significantly different from traditional risks from pesticides and other chemicals, and that there is a need for tailored environmental management approach for dealing with antibiotics and other pharmaceuticals.
Key words: QSAR, Pharmeceuticals, Ranking, HQ