The Impact of Phosphate Mine Tailings on the Bioaccumulation of Heavy Metals in Marine Fish and Crustaceans from the Coastal Zone of Togo

Abstract

About 2.5 million t of sedimentary phosphorite mine tailings, highly enriched with Cd, Cr, Cu, Ni, Fe, F, and Zn, are dumped annually in the coastal waters of Togo without any pre-treatment, causing serious pollution problems in the region. We conducted bioaccumulation investigations on fish and crustaceans sampled from the polluted coastal zone. The highest concentrations of metals in fish and crustacean were found close to the tailings outfall and the values decreased further away from the source of pollution. Compared to the international reference norms for seafood given by the WHO, Cd is enriched 10 to 168 fold, Pb 20 to 107 fold, Cu up to 5 fold, Fe up to 15 fold, and F up to 3 fold.

Bassin d'oued Serrat : terrils et rejets domestiques, reconnaissance des métaux lourds et polluants, impact sur les eaux souterraines (nord-ouest de la Tunisie)

“…qui a fonctionné de 1893 jusqu'en 1993, a engendré des centaines de milliers de mètres cubes de terrils riches en métaux toxiques (mLAyAH et al, 2009;ZAiER, 1999). Plusieurs études ont montré que les mines de phosphates en Tunisie, comme dans le reste du monde, présentent des teneurs élevées en métaux (ANOUAR et al, 2006;BEJi SASSi et SASSi, 1999;GNANDi et al, 2006;TLiG et al, 1987). Dans le but de déterminer les éléments indésirables qui peuvent détériorer la qualité de l'eau, sept échantillons représentatifs ont été prélevés au niveau du terril de la mine de K. Kh (KK1-KK7).…”

Towards Regulatory Criteria for Discharging Iron-rich Mine Water into the Sea

“…Extreme concentrations of Fe in near-shore marine waters can be expected to lead to bioaccumulation of Fe in fish and crustaceans to levels in excess of human consumption guidelines (cf. Gnandi et al 2006). It is stressed that no such cases have been reported in practice in relation to coal mine discharges.…”

“…The limited data available are consistent with the conclusion that direct toxicity effects of Fe and Al in marine waters are likely to be negligible for all but the most extreme loadings (cf. Younger 2000; Gnandi et al 2006). Although Al is strongly toxic to freshwater organisms, it quantitatively precipitates as innocuous Al(OH) 3 wherever pH rises above 4.5-which is inevitable upon mixing with well-buffered sea water.…”

Did Socially Responsible Investment Create the Added Value for the Company? A study Case in the Company of Phosphate of Gafsa

“…According to Jarvis et al (1994), phosphate rocks contain many metal elements, some of them, are considered as impurities and therefore have negative impacts on the environment. Gnandi et al (2006) emphasize in their studies dealing with the environmental impacts of mining and processing of phosphates, that many diseases such as dental fluorosis in children are strongly linked to the presence of fluorine in phosphate rock.…”