Metal Contamination and Health Risks in West African Mud Creeper (Tympanotonos fuscatus var radula) from Abule-Agele Creek, Nigeria.

This study assessed the seasonal distribution of trace metals in soft tissues of Tympanotonos fuscatus var radula, surrounding water, and sediment of Abule-Agege Creek in Southwest Nigeria. A non-significant variation (p > 0.05) in water physicochemical parameters occurred across wet and dry seasons. Metallic contamination (Copper, zinc, mercury, chromium, lead and cadmium) was found to be higher in T. fuscatus var radula than in water, and the sediment serves as a large depository of these trace metals. In this gastropod, the ability of metal accumulation from water (Bio-water accumulation) was higher than that from sediment (Bio-sediment accumulation). In addition, the linear regression models revealed positive relationship between tissue and sediment concentrations of lead and cadmium for both seasons. The estimated daily intake of investigated metals for both seasons was lower than the oral reference dose, while the target hazard quotient and total hazard index of individual metals were both less than 1, meaning that T. fuscatus var radula from the study region posed no health risk.

Chemometric estimation of captured Farfantepenaeus notialis, Pérez-Farfante 1967 (Crustacea: Penaeidae).

BACKGROUND: Chemometrics can be used to analyze a wide range of food products for authentication, quality control, differentiation and the determination of nutrition quality. Owing to the scarcity of studies relating to the intrinsic physico-chemical characteristics of penaeid shrimps caught on the Nigerian coast, the aim of this research was to estimate the energy-supplying nutrients, mineral elements and functional characteristics of Farfantepenaeus notialis from the Lagos Lagoon. METHODS: The proximate composition was determined using the AOAC method while the energy-providing nutrients were multiplied by the Atwater factors. The samples were digested in HNO3/HCl for mineral determination and the functional properties were estimated using optical measurements. RESULTS: Higher concentrations of moisture, crude protein, crude fat, and carbohydrate were recorded in the flesh while crude fibre and total ash were higher in the exoskeleton samples. The flesh had higher total metabolisable energy (1524 kJ 100 g-1) and utilizable energy due to protein (36.49 kJ). All the investigated minerals (Ca, Mg, K, P and Na) were more concentrated in the exoskeleton. In both samples, Na/K and Na/Mg ratios were within acceptable ideal ranges of 1.4-3.4 and 2-6, respectively. All values of the MSI (calculated) were lower than their comparative standard index values, having positive contrasts in both exoskeleton and flesh samples. The exoskeleton sample had better functional properties, but the flesh sample was higher in swelling strength. CONCLUSIONS: In addition to good flesh quality, F. notialis contains considerable amounts of energy-providing nutrients. As the content of fibre is very low, F. notialis may be ideal as a weaning food for children.

Target hazard quotient evaluation of selected trace elements in highly consumed crustacean species in Lagos, Nigeria

Crustaceans are known for their trace element bioaccumulation abilities. Muscle tissues of lagoon crab, marine crab, pink shrimp and mantis shrimp marketed for consumption in Nigeria were analyzed for Mn, Fe, Cu, Zn, Hg and Cr levels using standard methods. Muscle levels in mg kg-1 of Mn (0.03±0.00 in lagoon crab), Fe (0.072±0.01 in mantis shrimp), Cu (0.344±0.01 in lagoon crab) and Zn (0.073±0.00 in mantis shrimp) were significantly different (p Cu > Zn > Fe > Mn > Cr. Lagoon crab showed the highest total hazard index among the organisms with 44.80 %, while the least was observed in mantis shrimp with 13.30 %. It is concluded that, as far as human health is concerned, the mean elemental levels in the muscle tissues of the organisms examined pose no danger (THQ < 1).