Silver discharged in effluents from image-processing services: a risk to human and environmental health

In Brazil, only 20.2% of the municipalities have sewage collection and treatment. The use of medical diagnostic by radiographic processing generates effluents which may contain contaminants such as silver (Ag) that causes irreversible damage to health. They can also contaminate soil, water, and food if there is no treatment before disposal. This study aimed to identify and quantify the Ag concentration in radiographic film-washing water and fixer generated from radiographic processing in 12 Brazilian health institutions, in order to offer subsidies to the environmental and public health managers about this issue. The Ag values found in the washing water films samples ranged from 0.1 to 1,785.97 mg L(-1). In the fixer samples, the values ranged from 435.59 to 16,325.92 mg L(-1). These data are far above the values required by Brazilian legislation whose limit is 0.1 mg L(-1) for Ag in effluents released directly or indirectly into the environment. This research reveals that the disposal of Ag in this kind of effluent needs to be monitored and controlled by the Brazilian government in order to protect both the human and environment health from those contaminants.