Spectroscopic Analysis of Selected Priority Trace Metals in the Extant East African Gilled Lungfish (<i>Protopterus amphibius</i>) in Lira Municipal Lagoon and Its Edibility Health Risk

Abstract

This investigation analyzed the concentrations of three trace metals in gilled lungfish of Lira Municipal lagoon of Lira District and estimated the health risk associated with its consumption. Three fresh lungfish samples from the down, middle and up sluices of the lagoon were caught, eviscerated, washed and sundried. Edible muscles of the samples were oven dried at 105°C, desiccated and pulverized. 2.0 ± 0.1g of the fine fish powders were ashed at 550°C, acid digested, and the filtrates used to prepare 1 litre sample solutions. The sample solutions were analyzed for Lead, Zinc and Cadmium by Atomic absorption spectrometry. Spectroscopic results showed that no Cadmium was detected while the statistical mean concentrations of Zinc and Lead in the fishes from down, middle and up streams in mg/kg were 157.8 ± 0.01, 160.2 ± 0.02, 158.2 ± 0.01 and 6.84 ± 0.01, 1.69 ± 0.03, 5.12 ± 0.01 respectively. The above results showed that the trace metals in the investigated fish samples are deleteriously above the maximum permissible Zinc (0.7mg/kg) and Lead (0.3mg/kg) levels in fish indicated by CODEX STAN 193-1995. The statistical Estimated Daily Intakes were from 26.27 to 26.66 mg/kg/day for Zinc and 0.28 to 1.48 mg/kg/day for Lead. A heightened Health Risk Index value of 88.67 for Zinc was observed in the middle stream lungfish samples while Lead had the lowest Health Risk Index value of 2.00 in the middle stream fish from the lagoon. All the Health Risk Index values were greater than unity except for Chromium that was undetected in the fish muscles thus the lungfish of the lagoon is unsafe for human consumption and continuous consumption will impact human health. The immediate strategy lies in fencing the lagoon area and putting a stringent restriction against fishing from the lagoon.

Peer Review #2 of "Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of Namukombe stream, Syanyonja, Busia, Uganda (v0.1)"

“…Thus, for the general population, dietary intake is the dominant exposure pathway to mercury. Though the levels of THg in the edible muscles of O. nilotica consumed by the local community of Syanyonja village registered in this study are evidently low, the effect of mercury accumulation should not be overruled as other metabolically active organs such as the gills, liver and kidneys might contain higher THg concentrations [31]. Dietary exposure to mercury has been proven to cause elevated risks of cardiovascular diseases with severe exposure negatively impacting the reproductive and immune systems [112,113].…”

“…These provide the relative availability of mercury but does not take into cognizance the possibility of metabolic ejection of mercury. EDI in μgg -1 day -1 was calculated using Equation 1 previously employed elsewhere [31] while ADD therm (μgg -1 day -1 ) was calculated from Equation 2 [37][38][39].…”

“…Health risk index, the total risk of a non-carcinogenic element through three exposure pathways was evaluated using Target hazard quotient in accordance with US EPA region III riskbased concentration table [47] used in a preceding study [31]. According to the criterion, target hazard quotient less than unity (1.0) indicate that the exposure is very unlikely to have adverse effects while target hazard quotient greater than 1.0 represent a possibility of non-carcinogenic effects, with its probability increasing as the value of the target hazard quotient increases [31]. Target hazard quotient was calculated as the ratio of EDI or ADD therm to the reference dose (R f D) (Equation 3) [31,38].…”

“…According to the criterion, target hazard quotient less than unity (1.0) indicate that the exposure is very unlikely to have adverse effects while target hazard quotient greater than 1.0 represent a possibility of non-carcinogenic effects, with its probability increasing as the value of the target hazard quotient increases [31]. Target hazard quotient was calculated as the ratio of EDI or ADD therm to the reference dose (R f D) (Equation 3) [31,38]. Manuscript to be reviewed…”

Physicochemical Quality of Water and Health Risks Associated with the Consumption of the Extant African Lung Fish (<i>Protopterus annectens</i>) from Nyabarongo and Nyabugogo Rivers, Rwanda

“…The samples were placed in a cooler box with ice and transported to the laboratory where they were stored at 4℃ until commencement of analysis. African lung fish samples (6.2 to 8.1 cm fork length; 700-903 g fresh weight) were caught using hooks fed with earthworms as baits with the help of local fishermen [24]. Fish samples were only obtained from Nyabarongo river because fish caught from Nyabugogo river were small sized and not of edible size thus would not give representative samples.…”