Search

Profile assessment of the behavior of total polycyclic aromatic hydrocarbons (TPAH – sum of 16 US EPA priority PAHs) in water and suspended particulate matter (SPM) from Cross River estuary, SE Nigeria in response to hydrological cycles and human-induced activities as well as their sources were undertaken using gas chromatography-flame ionization detector (GC-FID). TPAH concentrations in water were in the range 0.23–3.98 ng/L, with a minimum and maximum values found in April and December, respectively (mean = 0.97 ± 0.65 ng/L) having higher concentrations in the dry season. The low PAHs levels recorded in water for the wet season were linked to dilution effect. On the other hand, TPAH concentrations in SPM (suspended particulate matter) ranged between 5.16 ng/g in February and 40.52 ng/g in June (mean = 17.77 ± 8.48 ng/g). Higher PAHs levels found in the wet season were associated with greater wash-in of terrigenous materials occasioned by intense rainfall events via river discharges/wet precipitation coupled with the high adsorption capacity of PAHs toward solid matrix as well as proximity to fish settlement. Seasonal changes in salinity, temperature and suspended sediment concentration (SSC or SPMC) somewhat influenced the PAH phase association. Higher SSC in the wet season accounted for the higher PAHs levels in SPM (r = 0.9295), whereas lower salinity aided desorption from SPM in the wet season, temperature did not show regular trend with PAHs levels in both seasons. Application of principal component analysis (PCA) and multiple linear regression (MLR) to both water and SPM data indicated a scenario predominated by petroleum and wood combustion PAHs with a moderate vehicular exhaust emission and coal tar inputs (11%). [ABSTRACT FROM AUTHOR]

The concentrations of the 16 priority polycyclic aromatic hydrocarbons (PAHs) in tea infusions made of water and local gin (alcohol) were investigated with a view to providing information on the profiles and health hazards associated with these two common Nigerian methods for tea consumption. The water-based tea infusion was prepared by submerging 4 g of tea in boiling water and allowing it to stand for 15 min, while the gin-based infusion was simply prepared by submerging 4 g of tea in gin at room temperature and allowing it to stand for 15 min. The concentrations of the ∑16 PAHs in the infusions were measured by using gas chromatography equipped with a flame ionization detector (GC-FID) after ultrasound-assisted extraction and clean-up. The concentrations of the ∑16 PAHs ranged from 24.9–623.4 μg kg−1with a mean value of 177 μg kg−1and 36.8–438.3 μg kg−1with a mean of 189 μg kg−1for water- and local gin-based infusions, respectively. The concentration of the ∑16 PAHs in the water- and local gin-based infusions of these teas were high when compared with levels reported in the literature for tea infusions. The local gin-based infusions had a higher mean level of the ∑16 PAHs than the water-based infusions. Four- and five-ring PAH compounds were dominant in these tea infusions. [ABSTRACT FROM PUBLISHER]

Concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in 40 brands of biscuits in the Nigerian market. The analyses were performed by gas chromatography-flame ionisation detection (GC-FID) after Soxhlet extraction of the sample with hexane/dichloromethane and clean-up of the extract. The concentrations of Σ16 PAHs in these biscuit samples were in the range of 35.7–645.3 μg kg−1, 75.9–490.7 μg kg−1, 91.5–537 μg kg−1, 18.4–522.2 μg kg−1, 123.5–393.8 μg kg−1, 167.2–880 μg kg−1, 136.5–316 μg kg−1, and 135.5–241.6 μg kg−1for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The concentrations of Σ8 carcinogenic PAHs in the samples ranged from not detected (nd)–323.3 μg kg−1, 15.7–138 μg kg−1, 9.7–312.9 μg kg−1, nd–331.7 μg kg−1, nd–220.9 μg kg−1, nd–53.3 μg kg−1, 18.4–56.6 μg kg−1, and 6.6–170.8 μg kg−1for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The margin of exposure (MOE), based on PAH8 as an indicator for the occurrence and effects of PAHs in food, was less than 10,000, the serious health effects value, in 30% and 8% of the brands for the child and adult scenarios, respectively. [ABSTRACT FROM PUBLISHER]

Concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) were determined in selected popular brands of canned fish (mackerel, sardine, and tuna) consumed in Nigeria with a view to providing information on the health risk associated with consumption of these products. The concentrations of PAHs were measured by gas chromatography equipped with flame ionization detection (GC-FID) after dichloromethane/hexane extraction and clean-up. The concentrations of Σ16 PAHs in these brands of canned fish varied from 174.6 to 350.8 μg/kg, 187.4 to 592.5 μg/kg, and 204 to 264.6 μg/kg for mackerel, sardine, and tuna, respectively. Benzo(a)pyrene was detected in 48% of the investigated brands at concentrations higher than the maximum tolerable limit of 5 μg/kg. The daily intake of PAHs from the consumption of any brand of these canned fish ranged from not detected (nd) to 54.3 ng BaP/kg bw/day, nd to 56.4 ng PAH2/kg bw/day, nd to 86.4 ng PAH4/kg bw/day, and nd to 153.7 ng PAH8/kg bw/day. The estimated margin of exposure (MOE) values (BaP-MOE, PAH2-MOE, PAH4-MOE, and PAH8-MOE) in a significant proportion of the brands was less than 10,000, which indicates a potential health risk for the consumers of these brands of canned fish. [ABSTRACT FROM AUTHOR]

The effects of culinary practices such as boiling, frying, and grilling on the proximate compositions and concentrations of metals (Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg) in commonly consumed fish species from the Nigerian coastal waters were investigated. The selected fish species were Polydactylus quadratifilis, Chrysicthys nigrodigitatus and Cynoglossus senegalensis. The culinary practices lead to increased protein, fat, and ash contents and decreased moisture contents of these fish species. The culinary practices resulted significant increase in the concentrations of most of the studied metals and decrease in the concentrations of Fe, Cr, and Pb in some fish types. The concentrations and estimated dietary intakes of Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg from consumption of the processed fish were within their statutory safe limits. The individual metal target hazard quotient ( THQ) values and the total THQs were less than 1 which indicates that no health risks would arise from the long-term consumption of these fish species. [ABSTRACT FROM AUTHOR]