Assessment of Hg accumulation in fish and scalp hair in fishing communities along river Swat, Pakistan

Mercury (Hg) bioaccumulation in fish poses severe threats to the food safety and human health. This study was conducted to assess Hg bioaccumulation in fish (n = 24) and scalp hair (n = 77) of the fishing communities at up- and downstream of the river Swat, Pakistan. The mean Hg concentration in upstream fish Salmo trutta fario (Brown trout) and Schizothorax plagiostomus (Swati fish) species was 34.7 +/- 18 mu g kg(-1) and 29.4 +/- 15 mu g kg(-1), respectively. The mean Hg concentration in downstream Swati fish, Crossocheilus diplochilus (Spena deqa), and Garra gotyla (Tora deqa) was 65 +/- 21 mu g kg(-1), 123 +/- 33 mu g kg(-1), and 326 +/- 53 mu g Kg(-1), respectively. The mean Hg concentration in scalp hair of the up- and downstream fishing communities was 658 +/- 125 mu g kg(-1) and 3969 +/- 791 mu g kg(-1), respectively. Independent T-test showed significant difference (p < 0.001) in the mean Hg concentration in scalp hair of the up- and downstream communities. The most prevalent health problems found in the fishing community were muscle pain, headache, visual impairment, arterial blood pressure, anemia, and kidney dysfunction. Multiple linear regression indicated that daily and weekly consumption of the fish significantly increase Hg accumulation in human scalp hair. Regular consumption of fruits and cruciferous and leafy vegetables were found to reduce Hg toxicity in the population. Further studies are recommended to identify the sources of Hg and welfare impact of fish contamination on the fishing community of river Swat.

Automated summary

Mercury bioaccumulation in fish and scalp hair was assessed in fishing communities along the river Swat in Pakistan. Significant differences were found in mercury concentrations between upstream and downstream fish and scalp hair. Health problems in the fishing community were attributed to mercury accumulation from fish consumption.