Using Historical Experimental Information in Aquatic Toxicity Testing

• Activity Number: 156
• Type: Topic Contributed
• Date/Time: Monday, August 4, 2014 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Jing Zhang*+ and A. John Bailer and James T. Oris
• Companies: Miami University and Miami University and Miami University
• Keywords: aquatic toxicology ; Bayesian ; potency estimation ; power prior ; zero-inflated

Abstract

An important advantage of using Bayesian method is the ability of incorporating historical data or ``expert" knowledge into the analysis via prior elicitation. This is useful in the analysis of small scale experimental results, which is often observed in reproductive aquatic toxicology experiments. In order to evaluate the potential adverse impact of chemicals on the reproduction of organisms living in receiving waters, marine systems, and other ecosystems, organisms are typically assigned into several groups (including a zero-exposure control group) and exposed to group-specific concentrations of the chemical in a single experiment. Based on this experiment, a relative inhibition concentration (RIp) associated with a specific level of inhibition relative to control results can be derived. A laboratory that conducts these experiments often conducts a large number of studies in a particular year, which provides lots of ``historical data" that can be utilized in the analysis. The present study explores the application of power priors in the reproductive toxicity assessment and illustrate the impact of historical information on the analysis when different models were used.