**1. Introduction**

Heavy metal pollution is one of the challenges of coastal waters due to human activities such as oil exploration and exploitation, construction and fabrication of marine boats, disposal of industrial and domestic wastes, sailing and illegal bunkering activities [1]. Heavy metals are generally referred to as those metals which possess a specific density of more than 5 g/cm3 and adversely affect the environment and living organisms [2]. Nagajyoti et al. [3] and [4]; stated that metals are significant environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional and environmental reasons. Heavy metal contamination in the aquatic environment is a major challenge with regards to industrialization in view of the fact that industrial and domestic wastes containing such pollutants are regularly channeled into nearby water bodies [1]. Increase in population has induced urbanization and industrialization with corresponding discharge of wastes such as heavy metals into the environment [5, 6] but Dural et al. [7] stated that heavy metals occur naturally in aquatic ecosystem but deposits of anthropogenic origin increase their levels and create environmental problems in coastal zones and rivers. Aquatic organisms like periwinkles have the ability to accumulate and bio-magnify contaminants like heavy metals, polycyclic aromatic hydrocarbons and PCB in the environment [8]. Researchers had stated that ideal bio-indicators (biomonitors) should satisfy certain conditions such as ability to accumulate pollutants without being killed by the levels encountered in the environment; sedentary in order to be representative of the study area, sufficiently long lived to allow the sampling of more than one year-class, if desired: be of reasonable size, giving adequate tissue for analysis [9, 10]. Mollusks such as *Tympanotonus fuscatus*, a deposit feeder common along the mangrove intertidal coast and estuarine swamps of the Niger Delta also satisfy most these conditions due to wide usage in biomonitoring studies [11]. Moslen [11] reported gradual bioaccumulation of heavy metals in fish (biota) with attendant minimal to moderate health risk concern but recommended regular monitoring in order to detect changes over time. *Tympanotonus fuscatus* is a mollusk (Gastropods) of high commercial and economic value in the Niger Delta region of Nigeria [11]. This study therefore, aim to evaluate consumption safety and heavy metal bioaccumulation in periwinkles (*Tympanotonus fuscatus*) obtained from Ogbia in Niger Delta, Nigeria.
