The authors regret that there were some errors in the text. The corrected text is given below.

## Introduction

Page 229, Second paragraph should be shown as:

Toxins can be classified on the basis of the symptoms produced in humans and other vertebrates – e.g., hepatotoxins, neurotoxins and irritant-dermal toxins. The hepatotoxins include the microcystin (MC) toxins such as MC-LR, MC-RR and MC-YR, which have high potential for contaminating drinking water (Carmichael et al. 2001).