HEAVY METAL POLLUTION
ABOUT ME PRAGATI MISHRA Compeleted Bsc Biotech ( Top Rank 3 in S.P UNIVERSITY) Msc Biotech: Selected for a dissertation research work on"ORGANIC SOLVENT TOLERANT LIPASE PRODUCING MICRO- ORGANISMS ISOLATION". Hobbies: Mimicry, Singing , Dancing Goal: To clear UPSC CSE My inspiration: My Father
WHAT IS A HEAVY METAL? o A metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight o Toxic in nature o Non bio degradable o Eg:- Mercury, Lead, Cadmium, Arsenic, etc..
HEAVY METAL POLLUTION High atomic weight metals (mercury, lead etc.) Sometimes the term trace elements is used to include non-metal and lower atomic weight elements Many of these elements are essential to the body in ver low concentrations: o Iron - essential for hemoglobin, Iron-sulfur proteins o Copper - essential for hemocyanin (in invertebrates) o Cobalt - in vitamin B, o Zinc essential component of many enzymes 12
HEAVY METAL POLLUTION But in high concentrations these can be toxic. e.g. one asprin tablet is a useful medicine but 100 tablets are lethal Some heavy metals have no essential function in the body (e.g. mercury, lead) and any concentrations can be harmful
What causes heavy metal pollution?
BIOACCUMULATION Most plants and animals can regulate their meta content to a certain point - but metals that can' be excreted build up in an organism over its lifetime BIOACCUMULATION An example of bioaccumulation is the use of DDT as an insecticide in the 1950sand 1960s. Birds of prey were badly affected because it made the shells of their eggs very thin, causing them to break easily when the birds tried to incubate them
BIOMAGNIFICATION Animals feeding on bioaccumulators take in a higher level of contaminants, which bioaccumulate within themselve:s Those animals feeding on them gain even higher inputs of contaminants, and bioaccumulate eve greater concentrations and so on... with animals at the highest trophic level obtaining highest concentrations BIOMAGNIFICATION
TOXIC EFFECTS OF MERCURY o Mercury can cause neurological damage, immune system suppression and can cause fetal abnormalities in mammals e In hurrianis it hhas beei associated with various neurological effects, abnormal development and heart damage