Plenary Lecture

A New Technique for Biological Monitoring

 
Professor Fukiko Ueda
Nippon Veterinary and Animal Science University
Japan
E-mail: fueda@nvlu.ac.jp

Abstract: Biological monitoring using wildlife is a useful method of investigating environmental contamination. We have been measuring the levels of contamination in wild birds caused by exposure to several toxic elements including cadmium (Cd) since 1992, in order to evaluate the degree of biological contamination. However, such studies are often limited by a lack of epidemiological information for wildlife, such as information on age, sex, migratory patterns and food habitants/diet, and it is often not possible to compare the same species in different countries. Further, most biological monitoring studies using wildlife have usually compared the mean metal levels in the organs, in spite of obtained individual data often representing a wide range of values. Extreme values found in wild populations may be identified statistically based on the results of experimental studies, but so many results from both experimental and wild animal populations are needed to assess the significance of the level of environmental contamination. Therefore, this method is opposed to the animal welfare spirit. How should we reduce a sacrifice?
We initially compared the data from wild bird populations with that from many references of Cd-uncontaminated animals including birds to access the significant contamination. In the process, we found out a new index of Cd uncontaminated animals. This new Cd index (Cd standard regression line: CSRL) is based on 101 data points selected from previous references. The data points represent the Cd contents (arithmetic means) of kidneys and livers from uncontaminated animals. This index has a significant correlation of R2=0.943, p<0.01.
The CSRL was compared with data obtained from animals experimentally administered Cd, and from humans, including patients with Itai-itai disease. The data from Cd-contaminated animals and patients diverged significantly from the CSRL, whereas the data from uncontaminated animals and human were in agreement with the CSRL. These results suggest that the CSRL could be a useful tool for assessing the levels of Cd contamination in animals. Comparison with the CSRL requires only a small sample size. Cd pollution should be suspected when the Cd contents of livers and kidneys from the target sample diverge significantly from the CSRL.
We are in the process of comparing data from more wild bird populations with the CSRL in order to confirm its usefulness in monitoring Cd levels in wild populations.

Brief Biography of the Speaker:
Fukiko Ueda (DVM, MSc, PhD) is a professor of Veterinary environmental Health at Nippon Veterinary and Animal Science University, Japan. Her research interests concern biological monitoring of heavy metals by wildlife, and concern molecular epidemiology of bacteria. Although her field is in the epidemiology of both a toxic substance and pathogenic bacteria, especially, she has been developing a new index in the biological monitoring for environmental pollutants, and has been reporting unique methods. Her area of expertise for government (key words) is “biological monitoring, wildlife, heavy metal, toxicology, molecular epidemiology, L. monocytogenes, bacteria, and food-poisoning”. She is an author and an editor of books on Japanese “Veterinary Public Health”. She is a member of the veterinarian-related committee of Ministry of Agriculture, Forestry, and Fisheries, Japan, and a member of the two committees of the Japanese Society of Veterinary Science and Japan Veterinary Medical Association.