Biomonitoring and Biomathematical Modeling of Health Risks Associated with Dumpsite Grown Vegetables in Lagos State

Conversion of dumpsites to farm lands in several communities is a usual practice in Nigeria. Wastes accumulate heavy metals in a variety of forms. This study assessed the concentration, degrees of contamination, and attendant health risk of heavy metals (HMs), using two major indigenous vegetables (Amaranthus viridis and Talinum triangulare) grown on five major dumpsites in Lagos state. After wet digestion, the mean concentrations of the HMs in the vegetable samples were evaluated using atomic absorption spectrophotometer (AAS). Daily intake of metals (DIM), target hazard quotient (THQ), and hazard index (HI) biomathematics were employed in the assessment of non-carcinogenic health risk. Incremental lifetime cancer risk (ILCR) assessment was used to assess carcinogenicity. The obtained result shows that the concentrations of HMs fell within the following ranges: (0.37 to 0.59), (0.07 to 1.36), (0.30 to 1.92), (0.00 to 0.03), and (0.00 to 0.04) mg/kg; for zinc (Zn), lead (Pb), Iron (Fe), cadmium (Cd), and chromium (Cr), respectively, with low to moderate variability. At Ikorodu dumping site, the Pb concentration was above the World Health Organization (WHO) permissible range and has the highest contamination factor. DIM for Pb was also above threshold values (> 1) in both adults and children, while the THQ values for Fe, Pb, and Cd were above 1 (> 1) in both adults and children. HI values for the vegetables exceeded WHO normal range (> 1), except Abule-Egba dumps' samples (70% HI greater than 1 in adults and 90% HI greater than 1 in children). Additionally, the ILCR values of above 50% of the samples were above the WHO (10-6) limits, with the highest value in children (Cd, 1.064 × 10-3) indicating high risk of carcinogenicity over a life time of exposure. Thus, the results revealed great health risk from consumption of vegetables from the four major dumping sites, with children being at greater risk.

Evaluation of corrosion and scaling potentials of oilfield waters in an offshore producing facility, Niger Delta

In this study, water samples from Miocene reservoirs, offshore Niger Delta, and seawater samples used for water injection were investigated in an attempt to examine the chemistry, evaluate the corrosion behaviour of steel, iron, and aluminium in different aqua media, and evaluate the scaling potentials of the oilfield produced waters (OFPW). Chemical analyses of the waters were determined; corrosion rate measurements were carried out by the weight loss method at room temperature while corrosion kinetics was carried out using conventional methods. Langelier saturation index (LSI), Ryznar stability index (RSI), Larson-Skold index (L-S), Puckorius scaling index (PSI), and aggressiveness index (AI) were evaluated for assessing the corrosiveness and scaling potential of the formation waters, using water quality data. The magnitude of corrosion of these metals was studied for an exposure period of 42 days. Chemical analysis revealed that the waters are slightly alkaline and generally classified as hard, saline water of the Na-Cl type based on its total dissolved solids (TDS). Produced water pH values range from 7.32 to 8.38. Results showed the likelihood of some of the water to form mild to severe scales based on the corrosivity indices, while the seawater samples are classified as 'non-aggressive' and 'aggressive'. Steel has the highest corrosion rate with a value of 3.84 × 10^-3 mg cm^-2 h^-1 compared to aluminium with the lowest rate of 0.37 × 10^-3 mg cm^-2 h^-1. In most cases, the rate of corrosion of the metals followed the first-order rate constant in some of the samples, and the second-order in others within the first seven days. It was observed that the rate of corrosion follows this order: steel > iron > aluminium. The potential heavy and intolerable corrosion associated with the use of these seawater samples as injection waters is a potential risk that must be handled by adequate treatment.

Ameloblastomatous Change in Radicular Cyst of The Jaw in a Nigerian Population

OBJECTIVE

To determine the incidence, age, gender, jaw-sites and subtypes of radicular cyst, and to determine the incidence of ameloblastomatous change in radicular cyst in a Nigerian population.

METHOD

A 10-year retrospective analysis of all diagnosed orofacial lesions in the Department of Oral Pathology and Medicine, University of Benin Teaching Hospital, Benin City, Nigeria.

RESULTS

From the 785 diagnosed orofacial lesions within the study period; there were 54 (6.9%) cases of radicular cysts of the jaws. The peak age group was the 3(rd) decade (n=23, 42.6%) with a mean age of 31 ± 1.7 years. There were 29 (53.7%) males and 25 (46.3%) females, giving a ratio of 1.2:1. The mandible was the commonest jaw-site (n=32, 59.3%). There were 12 (22.2%) cases of periapical cyst which were significantly associated with anterior maxillary site (n=8, 14.8%) [p=0.001]. Seven (13.0%) cases of cystic ameloblastoma were diagnosed among the radicular cysts, with a predilection of the lesions for 3(rd) and 4(th) decades of life (n=6, 11.1%), and posterior mandible (n=5, 9.3%).

CONCLUSION

This study showed a low incidence of radicular cyst of the jaw among orofacial lesions and a relatively higher incidence of ameloblastomatous change in radicular cyst compared to previous reports. Immuno-histochemical examination is recommended to differentiate radicular cyst with ameloblastomatous-like change from cystic ameloblastoma arising from radicular cyst.