Toxic Cyanobacterial Blooms: A Potential Challenge for Malaysian Water Safety

Abstract

Eutrophication increases primary productivity in water bodies and results in an increased incidence of excessive proliferation of algal biomass, particularly cyanobacteria. To date, the occurrence of high cyanobacterial biomass, known as bloom, is considered as a major threat to the safety of world’s water resources. This is due to the fact that cyanobacterial bloom could lead to serious negative impacts on public health and affect the stability of aquatic ecosystems with significant economic loss. Many cyanobacterial genera including Microcystis, Planktothrix, and Anabaena, produce hepatotoxic microcystins, which, if ingested, cause acute and chronicle poisoning in animals and humans. Due to their toxic characteristic, cyanobacterial bloom and the potential microcystin contamination have been seriously addressed in many countries throughout the world. To protect public health, World Health Organization (WHO) had set up provisional guideline values of 1 and 20 μg L-1 hepatotoxic microcystin for drinking and recreational water, respectively. In addition, some countries (e.g. Australia and Canada) have established slight variants of the guideline based upon their local requirements. However, the occurrence of toxic cyanobacteria and its risks on public health remains unclear and largely neglected in Malaysia. This is due to the fact that inadequate attention is drawn towards realizing the importance of assessing the risks of toxic cyanobacterial bloom in Malaysian water bodies. Due to the regional hot tropical climate and increasing nutrients input, it is becoming critical to address toxic cyanobacterial bloom issues in Malaysian water bodies. This paper aims to create awareness towards the potential occurrence and harms of cyanobacteria by providing an overview of toxic cyanobacterial bloom on a global scale, health risks associated with microcystin, and the importance of addressing this issue in Malaysian water bodies.