Blood, a specialized liquid tissue is not only a primary clinical sample for diagnosis of diseases, but also biological sample for assessing human exposure to environmental elements and for relating its higher status with environmental and occupational health risk. Lead among other trace elements, is best indicated by blood sample in comparison to other samples namely urine, teeth, hair, nail etc. Hence, blood lead levels have been widely assessed throughout world. The mean concentration of blood lead, lesser that 5 µg/dL is considered as the reference value useful for comparison between subjects of different places to recognize whether the subject is exposed to a particular source of lead pollution. Among other groups (adults, women and workers), pregnant mothers and children are studied generally for their exposure status, because they are most susceptible to toxic effects of lead. Blood lead levels of subjects from a region are compared with lead levels of environmental samples (air, water, soil, food) to find source and with their metabolic parameters and characters of several diseases to predict health hazards.
