Bioaccumulation of non-essential hazardous heavy metals and metalloids in freshwater fish. Risk to human health

Contamination of freshwater fish with toxic heavy metals and metalloids is a major environmental issue in terms of public health. For instance, Cd, Pb, Hg and As are biologically non-essential elements with known adverse effects. Consumption of fish contaminated with metals thus poses a risk to human health. Here we review the bioaccumulation of Cd, Pb, Hg and As in freshwater fish, and we discuss the associated risk to human health. We present possible routes for uptake of heavy metals and metalloids in fish. Various factors affect bioaccumulation in fish, such as fish feeding guilds. We also present various indices used to assess risk to human health, such as metal pollution index, health risk index, target hazard quotient and hazard index.