Polycyclic Aromatic Hydrocarbons (PAHs) Occurrence and Toxicity in Camellia sinensis and Herbal Tea

This study describes a survey of polycyclic aromatic hydrocarbon (PAH) concentrations in 23 green, herbal, and black tea brands widely consumed in Nigeria by determining the levels of benzo[a]pyrene, chrysene (PAH2), benzo[a]pyrene,chrysene, benz[a]anthracene, benzo[b]fluoranthene (PAH4), benzo[a]pyrene, benz[a]anthracene, benzo[k]fluoranthene, chrysene, benzo[b]fluoranthene,dibenz[ah]anthracene, benzo[ghi]per-ylene and indeno[1,2,3-cd]pyrene (PAH8). Toxic equivalence factor and mutagenic equivalence factor were applied to evaluate the toxic equivalence and mutagenic equivalence quotients relative to benzo[a]pyrene. The concentrations of PAHs indicate that Regulation 835/2011/EC was not fulfilled by benzo[a]anthracene, B[a]A, benzo[a]pyrene, B[a]P, benzo[b]fluoranthene, B[b]F, and chrysene, CHR. The PAH4 levels ranged from 1.28 to 44.57, 4.34 to 11.20, and 0.76 to 34.82 μg/kg in green, black, and herbal tea products, respectively. On the other hand, the PAH8 concentration varied between 1.63 and 65.73, 5.02 and 68.83, and 12.43 and 24.92 μg/kg in green, herbal, and black tea samples. The PAH4 and PAH8 provide more reliable indicators for determination of PAH contamination and risk characterization in food than PAH

Trace Metals Levels in Inorganic Fertilizers Commercially Available in Nigeria

Aims: To investigate the concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), vanadium (V) and zinc (Zn) in commercially available inorganic fertilizers (calcium superphosphate and urea). Place and Duration of Study: Urea and superphosphate fertilizers were purchased from a local market in Uyo, Southern Nigeria. Methodology: A total of twenty seven fertilizer samples were randomly taken representing triplicate samples from three urea and six superphosphate original fertilizer bags. Each sample were digested and extracted using the ethylenediamine tetraacetic acid (EDTA) extraction technique. The elemental analysis was performed using an inductively coupled plasma atomic emission spectrophotometer (ICP-AES) (Optima 3000 – Perkin Elmer). Results: The analyses indicated the presence of trace metals in commercially available fertilizers sold in Nigeria. Cadmium was found in comparatively high concentrations. Zinc was found present in relatively high concentrations in both urea and phosphate fertilizer samples but As was found in low concentration. By comparison, the superphosphat

Analytical Relevance of Trace Metal Speciation in Environmental and Biophysicochemical Systems

This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented

Trace Metal Contamination Characteristics and Health Risks Assessment of Commelina africana L. and Psammitic Sandflats in the Niger Delta, Nigeria

The purpose of this study was to investigate and quantify trace metal concentrations in Commelina africana L. and psammitic sandflats from an intertidal coastal ecosystem in Niger Delta, Nigeria, and to evaluate their spatial distribution, degree of contamination, and source apportionment.The environmental risks associated with soil contamination were elaborately assessed using potential ecological risk index, sediment quality guidelines, and enrichment relative to background levels. The mean concentrations of Cd, Cr, Ni, Pb, and Zn in sandflat soil samples are 0.76 ± 9.0 × 10−2, 7.39 ± 8.7 × 10−1, 2.28 ± 0.35, 0.024 ± 4.0 × 10−3, and 74.51 ± 2.55mg/kg, respectively. Metal levels indicate strong variability with sampling sites. The order of trace metal concentrations in the Commelina africana L. samples is Zn > Ni > Cr > Pb > Cd.The concentrations varied with the sample locations; and the levels of Pb (0.05 to 0.08mg/kg) at all locations are found to be significantly below permissible level of 0.3mg/kg. Potential sources of metal loadings may be associated with localised or diffused anthropogenic activities.The average carcinogenic risks are below 1.0 × 10−6 threshold values, and the sandflat soils are not considered to pose significant health effects to children and adult males and females. However, the carcinogenicity and noncarcinogenicity risks ranking decrease following the order children > adult males > adult females. Comparatively, the hazard quotient and hazard index indicate that the psammitic sandflats might pose a health risk to children in future