Evaluation of Heavy metals Concentration in Unshelled Periwinkle (Tympanotonus fuscatus) from Rumuolumeni Creek, Rivers State, Niger Delta Nigeria

Abstract

Abstract The study evaluated concentration of heavy metals in periwinkle (Tympanotonus fuscatus) from Rumuolumeni Creek. Globally pollution is one of the major problems affecting our environment that led to loss of many raw materials and extinction of animals and plant species. A lot of oil drilling activities by oil companies takes place daily at the creek including use of fertilizers by the local farmer, farming within the creek. Considering the importance of periwinkle (Tympanotonus fuscatus) a source of protein that is widely used in the preparation of food in Rivers State. It is important that the concentration of these heavy metals are known to ascertain their edibility. Samples were collected from four different stations with different anthropogenic activities; the stations were Mordant Marine, Erico, Old police post and Eagle Cement. Periwinkles were handpicked into rubber container washed with the river water to remove mud and taken to the laboratory where water were boiled for 20minutes using a ring boiler and soaked the periwinkles inside it before unshelling it with needle. Dry tissue samples of periwinkles weighting 0.5g were digested with 0.45ml of concentrated nitric acid in a fume cupboard and water bath were switch on, to stabilize and attain 1000C using a water bath completely, digested samples were filtered using whatman paper while heavy metals concentration were analyzed using Atomic Absorption Spectrophotometer (AAS), model AA320N. Heavy metals analyzed were (zinc, lead, copper and nickel). The periwinkles at all the stations investigated for heavy metals showed the following results (zinc 41.72-59.97, lead 0.750-1.639, copper 64.23- 115.50, Nickel 0.027-0.083) and all were compared with WHO permissible limits and all exceeded permissible limits of WHO except nickel. Conclusively the periwinkles at Rumuolumeni Creek are not healthy for consumption and the public should be alerted of the health risk in consuming the periwinkle from the creeks.