Industrialization and urbanization has increase the emission of pollutant into the environment; as such sensitive media subject to pollution (water, soil and air) has been infringed upon. Heavy metal is a potential pollutants found in Nigeria water sources. This study assessed the chronic daily intake (CDI) of heavy metal from potable water sources (surface and ground water) in the Niger Delta region of Nigeria. Secondary data (literatures) were used for the study. The study found the concentration of heavy metals under study to be above the permissible limit recommended by Standard Organization of Nigeria (SON), and the World Health Organization (WHO). The CDI of heavy metal for both children and adults were high ranging from 0.57 to 1436.33 μg/kg·day (iron), 0.00 to 323.33 μg/kg·day (zinc), 0.00 to 37.14 μg/kg·day (cadmium), 0.00 to 29.67 μg/kg·day (chromium), 0.00 to 116.67 μg/kg·day (lead), 0.00 to 123.33 μg/kg·day (copper), 0.00 to 21.33 μg/kg·day (nickel) and 0.00 to 78.0 μg/kg·day (manganese). The CDI value indicates that the consumption of these water sources without treatment could cause disease conditions. Hence, the water requires treatment prior consumption
