Mercury Human Exposure in Populations Living Around Lake Tana (Ethiopia)

Abstract

A survey carried out in Lake Tana in 2015 found that Hg levels in some fish species exceeded internationally accepted safe levels for fish consumption. The current study assesses human exposure to Hg through fish consumption around the Lake Tana. Of particular interest was that a dietary intake of fishes is currently a health risk for Bihar Dar residents and anglers. Hair samples were collected from three different groups: anglers, college students and teachers, and daily laborers. A questionary includes gender, age, weight, activity. Frequency of fish consumption and origin of the eaten fish were completed by each participant. Mercury concentrations in hair were significantly higher (P value <0.05) for anglers (mean ± standard deviation 0.120 ± 0.199 μg/g) than college students (mean ± standard deviation 0.018 ± 0.039 μg/g) or daily workers (mean ± standard deviation 16 ± 9.5 ng/g). Anglers consumed fish more often than daily workers and college group. Moreover, there was also a strong correlation (P value <0.05) between the logarithms of total mercury and age associated with mercury concentration in scalp hair. Mercury concentrations in the hair of men were on average twice the value of the women. Also, users of skin lightening soap on a daily basis had 2.5 times greater mercury in scalp hair than non-users. Despite the different sources of mercury exposure mentioned above, the mercury concentrations of the scalp hair of participants of this study were below levels deemed to pose a threat to health.

Factors affecting the mercury concentration in the hair of young residents of the Vologda region, Russia

“…Currently, most researchers conclude that fish consumption is a significant factor in the accumulation of heavy metal in the human body ( Ha et al., 2017 ; Sheehan et al., 2014 ; Hajeb et al., 2008 ; Masih et al., 2016 ; Pinheiro et al., 2005 ). For our sample - students of the first year of study at ChSU - higher levels of metal concentration in the hair are observed in individuals whose diets have fish intake more than 2–3 times a month, which is consistent with the results of previous studies in Germany ( Pesch et al., 2002 ), India ( Masih et al., 2016 ) and Ethiopia ( Habiba et al., 2017 ) according to which, the level of heavy metal in the hair rises with increasing frequency of fish consumption.…”

Mercury in fur of Daubenton’s bat (Myotis daubentonii) in Southern Sweden and Comparison to Ecotoxicological Thresholds

“…The amount of sample material collected could only be used for one analysis of each bat specimen. Analysis of hair replicate samples typically has a precision higher than 97% relative SD (Gashaw et al 2017 ).…”

A Drivers-Pressure-State-Impact-Responses Framework to Support the Sustainability of Fish and Fisheries in Lake Tana, Ethiopia

“…A plausible explanation could have been the occurrence of high concentrations of cyanobacteria. Of some fish species in the lake, mercury levels exceed internationally accepted safe levels for consumption [67]. Ahrens et al [68] also reported high concentration of perfluoroalkyl carboxylates such as PFCAs in water, sediment and fish of Lake Tana.…”

“…The effect is worse for the fishers whose day-to-day activity is in the lake, and to many people particularly children who are swimming in the lake. Furthermore, mercury levels higher than the internationally accepted safe levels for consumption [67] and high concentration of the perfluoroalkyl carboxylates [68] in some fish species are a great health concern for fish consumers.…”