Health and ecological risk assessment of metals in surface water from the Himalayan tributaries of the Ganga river, India

Table 5 HPI of surface water samples in the studied tributaries

Heavy Metals	Highest permitted value for drinking water (Si)	Maximum desirable value (Ii)	Unit weightage (Wi)	River	ΣQiWi	HPI
Mn	300	100	0.003	Ramganga	51.24	80.43
Cu	1500	50	0.001	Ghaghara	59.72	93.74
Pb		10	0.100	Gandak	16.94	83.13
Zn	15,000	5000	0.0001	Kosi	17.11	83.95
Ni		20	0.050
As	50	10	0.020
Se		10	0.100
Cd		3	0.333
Al	200	30	0.005
Cr		50	0.020
Ba		700	0.001
Fe		300	0.003

ISSN: 1467-4866