Pollute Indian coast with iron and carbon (1000kg) (6)
I believe the answer is:
infect
'pollute indian coast' is the definition.
'infect' can be an answer for 'pollute' (infecting is a kind of polluting). I am unsure of the 'indian coast' bit.
'with iron and carbon 1000kg' is the wordplay.
'with' is an insertion indicator.
'iron' becomes 'fe' (Fe is the chemical symbol for iron).
'and' is a charade indicator (letters next to each other).
'carbon' becomes 'C' (chemical symbol).
'i000kg' becomes 'int' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'fe'+'c'='fec'
'fec' going inside 'int' is 'INFECT'.
Can you help me to learn more?
(Other definitions for infect that I've seen before include "Affect (with a virus)" , "Cause sickness (with a virus)" , "Taint with disease" , "Transmit disease to another" , "Contaminate with disease" .)