Arsenic enrichment in mangroves,and sediments along Karachi coast,Pakistan

Objective:To assess the arsenic(As)concentration in different parts of mangroves Avicenniamarina and sediments in Karachi coastal area i.e.Korangi Creek,Manora,Kakapir and Sandspit.Methods:Sites are identified for sampling owing to their vicinity to industrial activities.Sandspit is targeted for its being devoid of industries.The hydride generation atomic absorption spectrometry(HG-AAS)were used to analyse the concentration of arsenic in mangrove and sediment.Results:The high concentration of As was found in roots and middle aerial part as compared to the upper part of mangroves.The concentrations of As was found higher in sediments as compared to the mangroves.There is a seasonal variation of As enrichment in mangrove and sediments as dry seasons showed higher concentration while in rainy season dilution factors may be attributed to the low level of As.The concentration variation of As in sampling sites of mangroves and sediments following the trend i.e.Korangi Creek>Manora>Kakapir>Sandspit.The statistical analysis(Two way ANOVA)of data exhibited no significant difference(P>0.05)for trace metals concentrations in mangrove as well as in sediments.Conclusions:It is obvious to conclude that As should be continuously monitored in different environmental segments.The data must correlate with geographical distribution of As,quantification in different species,their solubility and bioavailability to understand the possible factors responsible for environmental pollution.The present study will be helpful to improve water management resources.