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The aim of this study was to determine the levels of some trace metals in water from Cross River estuary (CRE) and estimate the human health risk associated with water from the estuary via ingestion pathway and dermal contact. The trace metals in water were determined using atomic absorption spectrophotometer and the human health risk assessment of the trace metals was carried out using models stipulated by United States environmental Protection Agency (USEPA). The range for the results in mg/l was as follows: Pb (0.193- 0.632), Cd (0.118 - 1.084), Ni (0.048 -0.632), Fe (0.056 - 0.921), Zn ( 0.063 - 0.242), Cu(0.072 - 0.146). All the investigated metals were above the WHO limit except zinc and copper. The target hazard quotient (THQ) via ingestion pathway for Pb, Cd and Ni were higher than unity. Also, the hazard indices for all the investigated metals in all the study sites were higher than unity. The target hazard quotient and Hazard index via dermal pathway were less than one for all the metal investigated, except Cd at Ebughu. Regular monitoring and minimization of anthropogenic activities resulting in elevated metal concentration is recommended.

Lignin, an amorphous biopolymer is one of the major components of wood. In this study,                         lignin was extracted from Gmelina arborea wood using Soda and Kraft pulping processes.                       The lignin was characterized using Fourier Transformed Infrared Spectrometer (FTIR),                     UV/visible spectrometer, electrospray ionization mass spectrometer and scanning electron microscope (SEM). Results revealed that G. arborea wood lignins contained several chemical functional groups. Kraft lignin (KL) contain carboxyl and thiol group in addition to other functional groups such as methoxyl, alcohols and phenolic. UV/ visible spectroscopy results revealed that Soda lignin (SL) absorbed at higher wavelength than Kraft lignin. The concentrations of both conjugated and non-conjugated phenolic group were higher in Kraft lignin than Soda lignin. ESI-MS spectra revealed that the composition of the monomers was higher in Kraft lignin while dimers composition was higher in Soda lignin. The surface morphology of both lignins were heterogeneous with uneven particle size. These physicochemical properties of lignin will enhance their  applications as adsorbents, corrosion inhibitors and in the production of some industrial chemical intermediates.