Principal Components and Hierarchical Cluster Analyses of Trace Metals and Total Hydrocarbons in Gills, Intestines and Muscles of Clarias gariepinus (Burchell, 1822)

Abstract

The aim of the study was to comparatively analyze the interrelationships among iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and total hydrocarbons (THCs) in the gills, intestines and muscles of Clarias gariepinus collected from Osse River, Nigeria, between the periods of April, 2013 to September, 2014. The trace metals in the fish tissues were analyzed using Atomic Absorption Spectrophotometer (AAS, Philips model PU 9100), while total hydrocarbons were analyzed using High Performance Liquid Chromatograph (HPLC,Prominence Dual brand from HGE) equipped with a detector Shimadzu UV-Visible (UV-Vis Prominence SPD 20 A). The concentrations of trace metals and THCs in the tissues were subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), backed up by correlation analysis (CA). In the most prioritized component among the hierarchies of contaminants, characterized as principal component 1, results of communality extractions and rotated component matrices revealed the order of contaminants was Mn > Cu > Zn > Fe > Cr in the intestines, Cr > Cu > THCs > Mn > Fe in the muscle, while Pb > Cr > Fe > Mn was the order in the gills of the fish. Iron inhibited accumulation of the other trace metals in the gills, where its threshold of essentiality was maximal. Noteworthy is the fact that Mn and Cu were the most active components in the muscle and concurrently of excess concentrations in the tissue, which is the major edible part of fish, and constitutes its main body weight, hence holds its nutritional and economic values. High level of variability which occurred in the toxicant profile across the tissues of C. gariepinus is a function of uptake route, varied organ functions and specificity of tissue permeability of the compared organs. The study demonstrated variability in organ accumulation capacity and toxicant’s competitiveness irrespective of bioavailability. The study provides data useful for future ecotoxicological studies and safety of consumers of the fish.

Health risk indices and zooplankton-based assessment of a tropical rainforest river contaminated with iron, lead, cadmium, and chromium

“…The calculated relative standard deviation (SD) was < 6% (determined by Microsoft Excel, 2010), indicating high data reliability. The reference solutions used to obtain the calibration curves were prepared from analyte grade stock solutions containing 1000 mg/L of lead, iron, chromium, and cadmium 15 . The blanks and reference solutions were also analyzed using the same method that was applied to the samples.…”

“…Ezemonye et al 43 USEPA 44 CF Conversion factor (kg/mg) www.nature.com/scientificreports/ The slope factor (SF) values for Fe, Cr, Pb, and Cd were adopted from Isibor et al 15 , while the standard limits were adopted from USEPA 42 for computations in Eq. (11).…”

“…Due to possible synergistic/ antagonistic interactions among the metals analyzed 15 , the cumulative hazard quotient (HI) was estimated as the sum of the overall non-carcinogenic risk posed by individual metal (IARC 53 , NRC 54 ).…”

“…HQ represents hazard quotients of the individual metal analyzed (Eqs. 15,16). HQ or HI < 1 = unlikely to cause adverse health effects for the exposed populace, while ≥ 1 = unacceptable.…”

Trace metals contamination potential and health risk assessment of commonly consumed fish of Perak River, Malaysia

“…The toxicity of these trace metals has proven to be a major threat, and there are numerous health impacts associated with it. The consumption of excess trace metal contained fish can malfunction the human digestive, cardiovascular and central nervous system [ 13 ]. In particular, prolonged exposure to metals such as Cd, Pb, and Cr, can cause cancer, liver damage, and eventual death of living organisms [ 14 ] Therefore, it is essential to study the trace metal concentration in fish species along with their both cancerous and noncancerous health risks to assure their harmless consumption.…”