Microcystins: Measuring human exposure and the impact on human health

Context: Freshwater cyanobacterial toxins, microcystins, may be a contributing factor to the development of hepatocellular cancer and colorectal cancer. Objectives: This review summarizes the toxicity data, exposure routes and the methodologies available to determine exposure to elucidate the relationship to liver and colorectal cancer. Methods: Literature searches were conducted using Medline, PubMed and Web of Science. Results: There is evidence of human poisonings resulting from exposure to microcystins, however current methods rely on targeted approaches only suitable for acute exposure. No methods exist for the determination of chronic exposure to microcystins. Conclusions: With the growing evidence of exposure to microcystins and the possible links to cancer, methods to measure medium to long-term human exposure are needed. The identification and validation of candidate biomarkers are key to undertaking urgently required epidemiological studies.