Determination of polycyclic aromatic hydrocarbons and potentially toxic metals in commonly consumed beef sausage roll products in Nigeria.

Levels of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic metals (PTMs) were determined in the commonly consumed beef sausage roll products (coded BS1 - BS6) in Nigeria. This was done in order to assess the safety of regular consumption of these products with respect to the substances determined. Three batches of six samples of beef sausage roll products were collected from Ile-Ife, Osun sate, Nigeria. A part of the pretreated sample was Soxhlet extracted using n-hexane and analyzed with Gas Chromatography coupled with Flame Ionization Detector (GC-FID) to identify and quantify each of the PAHs in the sample, while Atomic Absorption Spectrometer (AAS) was used to profile the concentrations of As, Cd, Co, Cu, Pd, Mn and Zn in the digested sausage roll samples. Levels of PAHs in the samples ranged from 1.84 µg/g of Acenaphthylene in BS5 to 282.83 µg/g of Benzo[k]fluoranthene in BS1. Concentrations of benzo[a]pyrene in all the samples were higher than the guideline value of 0.003 mg/kg/day. For PTMs, a range of 0.075 µg/g As in both BS1 and BS6 to 2.950 µg/g Cu in BS3 was obtained. The study concluded that both PAHs and PTMs occurred in the samples at levels that called for caution on the part of consumers to prevent health infarctions that might be associated with prolonged regular and large consumption of beef sausage roll products.

Heavy metals pollution in a sewage treatment oxidation pond and the receiving stream of the Obafemi Awolowo University, Ile Ife, Nigeria.

This work centered on a 1-year evaluation campaign of point source pollution from a sewage treatment oxidation pond and its receiving stream. Water samples were collected from the sewage treatment oxidation pond and the receiving stream during July 2002 and June 2003. Concentrations of heavy metals were determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after a triple acid digestion of samples using open beaker method. Generally, the results showed high levels of toxic metals such as Cd, Pb, As, Al, Cr, Mn, Co, and Fe in the influent and effluent samples as well as in the receiving stream. The annual mean concentration of metals in the sewage samples ranged from 11.90 to 16.05, 64.96 to 88.27, 38.91 to 76.35, 17.46 to 24.45 mug/L for Cd, As, Pb, Co, and 4.31 to 8.77, 1.71 to 2.45, 0.46 to 0.74 and 13.82 to 20.47 mg/l for Al, Cr, Mn and Fe, respectively; while in the receiving stream, the concentrations were between 6.89 to 10.45, 35.50 to 59.26, 22.85 to 35.94, 11.33 to 18.83 mug/l for Cd, As, Pb, Co, and 1.99 to 3.49, 1.35 to 2.08, 0.21 to 0.48, and 8.93 to 14.15 mg/l for Al, Cr, Mn and Fe, respectively. The discharge of the effluent from the sewage pond into the receiving stream has therefore led to increase in the concentrations of some heavy metals downstream, thus impacting the receiving stream negatively and could pose a serious health hazard to aquatic ecosystems and humans particularly for rural dwellers and peasant farmers downstream that utilize the water from the receiving stream for various domestic and agricultural purposes untreated.

Survey of levels of phthalate ester plasticizers in a sewage lagoon effluent and a receiving stream.

In this study, samples from a sewage treatment lagoon and those from a receiving stream were analyzed for their phthalate esters content. Knowledge of the distribution of ubiquitous phthalate esters in the sewage lagoon and the receiving stream was necessary because of the reports of their subtle toxicity to aquatic biota and humans. Liquid-liquid extraction, Clean-up experiment and High Performance Liquid Chromatography (HPLC) were the methods employed for the quantitative determination of the Phthalates. A study of uncontaminated water was done to establish blank levels. The sewage lagoon and the receiving stream were grossly polluted as several phthalate ester plasticizers: DMP, DEP, DPhP, DBP, DEHP, DOP and DINP were found present at monthly mean levels of between 24.02 mg/L and 139.25 mg/L in the sewage treatment lagoon and 10.41 mg/L and 80.53 mg/L in the receiving stream. The results showed higher levels of phthalate esters in the sewage lagoon compared to the receiving stream. The sewage lagoon was identified as a pollution point source into the receiving stream. Levels of phthalates obtained from the receiving stream are much higher than the water criteria of 3 microg/L phthalates recommended by the United States Environmental Protection Agency (USEPA) for the protection of fish and other aquatic life in water and the Suggested No-Adverse Effect Levels (SNAEL) of 7.5-38.5 microg/L for drinking water. This should give cause for great environmental concern. Peoples' health downstream is at stake and so is the 'health' of the ecosystem.

Determination of cadmium and lead in urine of some Nigerian subjects.

Forty-one urine samples of smokers and non-smokers from Ile-Ife, Nigeria were analyzed for normal cadmium and lead levels after acid digestion. Results of the preliminary study show that concentrations of cadmium obtained were generally low compared with lead. The mean urinary levels from non-smokers ranged from 0.05 - 0.02 to 0.16 - 0.01 wg ml-1 and from 0.02 - 0.03 to 0.88 - 0.04 wg ml-1 for cadmium and lead respectively, whilst, for smokers, urinary levels varied between 0.07 - 0.01 and 0.23 - 0.02 wg ml-1 and between 0.28 - 0.03 and 1.02 - 0.02 wg ml-1 were obtained for cadmium and lead, respectively. Cd levels in urine of smokers and non-smokers are higher than the recommended normal level of 0.0085 wg ml-1, while levels of Pb are above the 0.08-0.15 wg ml-1 exposure range. Results of spiking experiments with urine gave high percentage recoveries for both elements (Cd, 87.9 - 0.40%) and (Pb, 90.40 - 0.12%). Blank determination was done for background correction.