Assessment of the Ecological Risk from Heavy Metals in the Surface Sediment of River Surma, Bangladesh: Coupled Approach of Monte Carlo Simulation and Multi-Component Statistical Analysis

River sediment can be used to measure the pollution level in natural water, as it serves as one of the vital environmental indicators. This study aims to assess heavy metal pollution namely Copper (Cu), Iron (Fe), Manganese (Mn), Zinc (Zn), Nickel (Ni), Lead (Pb), and Cadmium (Cd) in Surma River. Further, it compares potential ecological risk index values using Hakanson Risk Index (RI) and Monte Carlo Simulation (MCS) approach to evaluate the environmental risks caused by these heavy metals. in the study area. With obtained results, enrichment of individual heavy metals in the study area was found in the order of Ni > Pb > Cd > Mn > Cu > Zn. Also, variance in MCS index contributed by studied metals was in the order of Cd > Pb > Ni > Zn > Cu. None of the heavy metals, except Ni, showed moderate contamination of the sediment. Risk index values from RI and MCS provide valuable insights in the contamination profile of the river, indicating the studied river is currently under low ecological risk for the studied heavy metals. This study can be utilized to assess the susceptibility of the river sediment to heavy metal pollution near an urban core, and to have a better understanding of the contamination profile of a river.

Effect of urbanization on heavy metal contamination: a study on major townships of Kannur District in Kerala, India

Background In the last few decades, the air, water, and soil are contaminated due to different anthropogenic activities and severely affect the environmental quality. Pollution is the harmful effect and creates undesirable changes in the land use and land cover pattern. The growth of urbanization leads to the degradation of the ecosystem and ultimately affects the living and non-living organisms. In view of these, the present investigation is carried out to assess the heavy metal pollution in major towns due to the impact of urbanization in Kannur district and desirable conclusions were drawn. Results The results shows that higher level of heavy metal pollution is observed in major towns of Kannur district. Conclusion The heavy metal contamination in the major towns of Kannur district is mainly due the anthropogenic activities. The discharge of domestic effluents and industrial waste is the major source of heavy metal pollution. In-depth studies and proper waste management plans are needed to decrease the level of heavy metal contamination prevailing in the study area.

SEASONAL VARIATION OF HEAVY METAL POLLUTION OF GROUNDWATER AND SOIL IN THE M’NASRA REGION (GHARB, MOROCCO)

M’nasra region is well known for increasing levels of heavy metal pollution in the environment, mainly due to waste discharge of Ouled Berjal, the irrational use of fertilizers, and the discharge of waste from several industries. The objective of this study was to access the seasonal variations in the groundwater and soil quality with respect to heavy metal pollution. Water samples from wells and samples from soil near them were taken during wet (January - March 2017) and dry (July 2017) seasons and concentrations of Cd, Cu, Cr, Mn, Ni, Pb, and Zn were determined using an Atomic Absorption Spectrophotometer (AAS). Contamination factor for each heavy metal and Nemerow pollution index was calculated. Results of the study revealed a decrease in pollution degree from wet to dry for soil and an increase in the case of groundwater. Cu had the lowest and Ni had the highest concentration in irrigation water whereas, for soil, Cd had the lowest and Zn had the highest concentration. During the wet season, all the concentrations of heavy metals decreased compared to the dry season, this can be explained by the dilution of these concentrations by precipitation water and therefore to lower absorption of these heavy metals in the water of irrigations and/or soil. Vertical transfer of pollutants from topsoil to groundwater was assessed using Hierarchical Cluster Analysis to identify associations between heavy metals and soil texture. In the case of Ni and Cr, the variables corresponding to the concentrations from soil and groundwater were part of the same cluster, in both seasons, the distribution maps of concentrations confirmed the pattern of transfer. This study can be considered as a baseline for the seasonal variation of heavy metal pollution of groundwater and soil. This study can be used not only for monitoring the study area but also as a tool for the implementation of environmental protection policies.