DETECTION OF CYANOBACTERIAL TOXIN MICROCYSTINS IN TREATED DRINKING WATER: A PRELIMINARY STUDY IN SELANGOR, MALAYSIASOM CIT SINANG, AMY ROSE AERIYANIE A RAHMAN AND CHEE FAH WONG
This study aimed to quantify microcystins concentration in treated drinking water in Selangor, Malaysia. In June and July 2020, one hundred and twenty tap water samples were collected from eight districts. Samples were treated with sodium thiosulfate to neutralise chlorine before microcystins analysis using enzyme-linked immunosorbent assay (ELISA). The analyses revealed that microcystins were present at low concentrations in 22 percent (N=26) of the total collected samples. Microcystins were detected in 27 percent to 53 percent of samples collected from Hulu Langat, Sepang, Gombak, Petaling, and Kuala Langat districts. On average, microcystins concentrations were below the maximum acceptable limit of 1.0 ppb, and ranged from 0.10 to 0.68 ppb across the positive tested samples. The highest mean microcystins concentration of 0.368 Â± 0.20 was detected in the Hulu Langat district. Overall, microcystins were detected from districts with their raw water sources derived from dams and retention ponds. These results suggest the presence of cyanobacterial toxin microcystins in treated drinking water supplies. Despite being detected at low prevalence and concentrations, microcystins in drinking water supplies could pose a potential health risk as toxin production at the cellular level can be highly variable on a temporal basis due to various environmental factors.