(D) (i) Bio-monitoring:
The use of living things to detect changes in the environment is called bio-monitoring. Both the occurrence of bio-accumulation and biological effects has often demonstrated useful and reliable information on the state environment. Bio-monitoring methods are cheaper, precise and sensitive to detect adverse conditions in the environment.

Both the natural and artificial substratum methods are so far being used for bio-monitoring. The Pollution Control Board, Assam has already started bio-monitoring in the regular water quality monitoring programme being conducted under the Monitoring of Indian National Aquatic River System. Some more projects under the guidance of CPCB are undergoing in the bio-monitoring laboratory. The list of parameters studied so far are :

The 4 (four) Regional Laboratories attached to the Regional offices at Sibsagar, Tezpur, Silchar and Bongaigaon are also equipped with manpower and equipments for analysis of environmental pollution related parameters for regular monitoring under their jurisdictions.