Distribution of heavy metals in Langat River

Rivers provide various kinds of utilization components to human. Development activities through discharge of effluents from different anthropogenic sources deteriorate the water quality and health aquatic ecosystem. The present study was conducted to determine the chemical composition of Langat River during northeast monsoon and inter-monsoon seasons. A total of 60 (30 water and 30 river bank soil) samples were collected from 15 different sampling stations from the upstream to downstream of Langat river. Seven heavy metals such as As, Cd, Cr, Ni, Pb, Cu, Mn were analyzed by using Inductively Coupled Plasma Optical Emission Spectrometry (/CP-OES). The results revealed that heavy metal concentration was higher in inter-monsoon season compared to northeast monsoon season. Similar pattern of heavy metal distribution both in water and river bank soil samples indicate that Langat River bank itself act as point source for heavy metal pollution. The mean concentrations of As. Pb and Mn in water exceeded the permissible limits proposed by MOH and US EPA for both seasons. Cd and Ni were above the permissible limits during inter-monsoon season while Cu and Cr were under the permissible limits for both of the seasons. The highest concentration of As was found at station 8 near to industrial sites indicating industrial source such as battery, metal scrap, plastic and fabric industry. Increase of human activities at station 1 has led to high concentration of Cd, Cr. Ni, Pb and Cu during inter-monsoon season. Mn was found the highest at station 8 during northeast monsoon season and station 10 during inter-monsoon season which were near to industrial activities and palm oil plantation respectively. These results are very crucial to understand the pollution in Langat River based on heavy metals and the effects towards human health and environment.