Elemental pollution status of different components of Ologe Lagoon, Lagos, Nigeria

This study evaluated the concentrations and distributions of nutrient and non-nutrient elements in water, sediment, mud, and vegetation of Ologe Lagoon, Lagos, Nigeria. Nutrient elements including Na, Ca, K, and Mg were found in high concentration values in the different components of the freshwater ecosystem. While the water had the least concentration of the elements, Trapa natans had the highest. Aluminium showed similar distribution patterns in the different components, except for T. natans. All the samples correlated significantly with water (p <0.05). Both the sediment and mud showed low potential ecological risk indexes of 5.3 and 5.92, respectively. Copper had the highest ecological risk with respect to single regulator indexes in the mud and sediment, notwithstanding its low concentration in the two components. Pollution indices suggested the low severity of non-nutrient elemental contamination of water, sediment, mud, and vegetation of Ologe Lagoon, and therefore, it is safe for human consumption, but not for agricultural irrigation. Pistia stratiotes and T. natans showed potentiality for use as photo-stabilisers and phytoremediators for some of the elements. The presence of radionuclides and rare earth elements in the components of Ologe Lagoon are instructive for specific policy initiatives to mitigate their effects on the population. HIGHLIGHTS Radionuclides were reported in the components of Ologe Lagoon, a freshwater ecosystem.; High nutrient-element concentration associated with increased salinisation were found in the different components of Ologe Lagoon.; There is a low contamination of the components of the Lagoon with respect to non-nutrient elements.; Water from Ologe is unsuitable for agricultural irrigation owing to high concentration of nutrient metal elements.; Pistia stratiotes and T. natans showed potential for the remediation of Zn, Cr, Cu, Th, and U.

Salmonella species on meat contact surfaces and processing water in Sokoto main market and abattoir, Nigeria

This study was carried out to determine Salmonella contamination of food contact surfaces and processing water in meat, fish and poultry processing units in Sokoto State, Nigeria. A total of 200 swab (100 from abattoir and 100 from poultry and fish markets) and 60 processing water samples (30 from abattoir and 30 from poultry and fish markets) were collected between May to August 2015. Cultural isolation, bio-typing and sero-grouping using Salmonella Sero-Quick Group Kit was conducted to analyse the samples. Seventy-five (75/260, 28.8 %) of the total samples were positive to Salmonella by cultural isolation and bio-typing. Thirty (30/130; 23.1 %) of samples collected in abattoir and 45 (45/130; 34.6 %) of those collected from poultry and fish markets were positive for Salmonella respectively. Sero-groups D+Vi (Salmonella Typhi), B (Salmonella Paratyphi B, Salmonella Typhimurium) and C (Salmonella Paratyphi C, Salmonella Cholerae suis) were identified as the prevailing sero-groups in this study. Sero-group D+Vi has the highest prevalence (73.3 %; 55/75) from the positive bio-typing isolates. This study revealed the presence of contaminating and pathogenic Salmonella on food contact surfaces and processing water in the meat retail markets, indicating there is an urgent need to improve on the hygienic status of retail meat, poultry and fish markets