LIST OF ABREVIATIONS AC Activated carbon ADD / ADI Average daily dose / Acceptable Daily Intake ALA Delta-aminolevulinic dehydratase BW Body weight CR Cancer risk CSF Cancer slope factor ED Exposure dose EF Exposed frequency ML HI Maximum level Hazard index HQ Hazard quotient HM Heavy metal Min Max Minimum Maximum RfD Reference dose USEPA United State Environmental Protection Agency WHO World Health Organization INTRODUCTION According to the World Health Organization (WHO), globally, there were 12.6 million deaths (23%) caused by environmental pollution in 2012. [1]. One of the major threats to ecological and human health is environmental contamination and pollution by heavy metals.