Water cytotoxicity and dioxins bioaccumulation in an Egyptian delta wetland ecosystem

El-Shazly, M. M., E. Elzayat, W. A. Omar, and M. M. S. K. M. A. R. M. S. I. & IIA El-Sebeay, YA Edmardash, "Water cytotoxicity and dioxins bioaccumulation in an Egyptian delta wetland ecosystem", African Journal of Aquatic Science , vol. 41, issue 3, pp. 289-296, 2016. copy at www.tinyurl.com/y42ss362


Manzala Lake, as one of the main Egyptian wetland ecosystems, is facing risks of pollution. An in vitro cytotoxicity
test using a mammalian cell line was employed to determine the toxicity of multiple pollutants in the water and
Tilapia zillii fish sampled from the lake. The concentrations of seven polychlorinated dibenzo-p-dioxins and ten
polychlorinated dibenzofurans were investigated in water and muscle of the fish in 2014. Cytotoxicity testing
showed that the percentage inhibition of cell viability in the studied sites ranged between 56.16% and 83.22%.
Dioxin analysis indicated that the average concentrations of 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin,
1,2,3,4,7,8-hexachlorodibenzofuran, 1,2,3,4,6,7,8-heptachlorodibenzofuran and 1,2,3,4,6,7,8,9-octachlorodibenzofuran
were higher than the toxic equivalence quotients (TEQs) set by the World Health Organization (WHO) in all water
and fish muscle samples; however, the average concentration of 2,3,7,8-tetrachlorodibenzofuran was higher only
in fish muscle samples. The bioaccumulation factor (BAF) ranged dramatically between 2 and 58.5 for the detected
dioxins. Adverse human health effects through the consumption of fish are not expected, because dioxin levels in
fish muscle are deemed safe for human consumption. Implementation of a strategic multidisciplinary action plan is
strongly recommended to sustain this delta wetland ecosystem.

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