Assessment of heavy metal accumulation in Penaeus monodon and its human health implications

COVID-19 induced lockdown reduced metal concentration in the surface water and bottom sediment of Asia's largest lagoon

COVID-19 (hereafter COVID) induced lockdown provided a unique opportunity to evaluate the effects of human activities on coastal ecosystems. This study quantified the seasonal variations in concentrations of nine metals (Al, Cr, Cd, Co, Cu, Fe, Mn, Ni, and Pb) in surface water and sediment samples of the largest brackish water lagoon in Asia (i.e., Chilika Lagoon), comparing pre-and post-COVID scenarios. The COVID lockdown resulted in a wide variation in metals concentrations, with surface water showing 1 to 8.6-fold reduction in metals such as Al, Cr, Cu, Fe, Mn, and Pb, while sediment displayed a more modest reduction of 1 to 1.3-fold. Metals like Cd, Co and Ni were below detection limit in post-COVID water samples with a slight decrease (1-fold) in the sediments. COVID lockdown did not show any significant correlation with metal concentrations in water or sediment. This study provides baseline data for metal contamination in the surface water and sediment of the Chilika Lagoon.

The Bioaccumulation of Heavy Metals in the Water and Tissues of Invasive Fish Carassius gibelio (Bloch, 1782) and Non-carcinogenic Health Risk Assessment from Meriç Delta Wetland, Türkiye

Meriç Delta, which has a wide variety of ecosystems, is an A Class Wetland and the most significant natural stagnant freshwater ecosystem located in the south-western of Thrace Region of Türkiye. In this research, heavy metals (Cr, Ni, As, Cd, and Pb) were investigated in the surface water and Carassius gibelio (Bloch, 1782) obtained from Meriç Delta lakes (Gala, Pamuklu, Sığırcı, and Dalyan), which are located on an important migration route of water birds. The heavy metals in surface water samples and fish tissues were determined by ICP-MS. Dissolved oxygen, oxygen saturation (%), pH, electrical conductivity, total dissolved solids, nitrite nitrogen, nitrate nitrogen, and total phosphorus parameters were measured in surface waters. High total phosphorus content was detected in the investigated region. The measured As, Cr, and Ni values in water samples were determined to be higher than Türkiye Regulation Standards criteria. Fish were taken from Gala and Sığırcı Lake. The mean concentrations of measured heavy metals were found to be below permissible values in fish muscle and gill. The target hazard quotient (THQ) and total THQ values (HI) of all heavy metals did not exceed the limit value.

Human health risk assessment of mercury in highly consumed fish in Salvador, Brazil

This work reports assessing risks to human health resulting from mercury levels in sardines (Sardinella brasiliensis), which have been highly consumed by the low-income population from Salvador, Brazil. Mercury was determined using the Direct Mercury Analysis (DMA) in fifty-one commercially acquired samples in seventeen neighborhoods. The mercury content on a wet basis ranged from 0.023 to 0.083 μg g-1 for an average value of 0.039 μg g-1. The estimated weekly intake (EWI), target hazard quotient (THQ), and maximum safe consuming quantity (MSCQ) were used in the toxicological assessment, and all these indices denoted that this food does not pose any risks to the human health of the population that consumes it. The development of this work was very significant because most sardines sold in Salvador originate from Todos os Santos Bay, which has a history of mercury contamination.

Evaluation of human health and ecological risk of heavy metals in water, sediment and shellfishes in typical artisanal oil mining areas of Nigeria

Heavy metal contamination in water and sediment is a serious concern in nations that depend heavily on natural resources such as Nigeria. In most coastal communities around oil mining areas in Nigeria, drinking water quality, staple food, and livelihoods are primarily dependent on ecological systems and marine resources (e.g., fish). Thus, humans and other receptors are exposed to heavy metal risks through ingestion and dermal contact. This research evaluated the potential ecological risks of heavy metals including Cadmium (Cd), Chromium (Cr), Nickel (Ni), and Lead (Pb) in water, sediments, and shellfishes (Callinectes amnicola, Uca tangeri, Tympanotonus fuscatus, Peneaus monodon) along the Opuroama Creek in Niger Delta, Nigeria. The concentrations of heavy metals were measured in three stations using the Atomic Absorption Spectrophotometer and their relative ecological (geo-accumulation index and contamination factor) and human health risk (hazard index and hazard quotient) analysed. The toxicity response indices of the heavy metals indicate that the sediments pose significant ecological risk particularly with Cd. None of the three exposure pathways to heavy metals in the shellfish muscles and age groups pose a non-carcinogenic risk. Total Cancer Risk values for Cd and Cr exceeded the acceptable range (10-6 to 10-4) established by USEPA in children and adults, raising concerns of potential cancer risks following exposure to these metals in the area. This established a significant possibility of heavy metal risks to public health and marine organisms. The study recommends conducting in-depth health analysis and reducing oil spills while providing sustainable livelihoods to the local population.