Table 3.

Drinking water contaminants and maximum admissible limit by different international organizations.

	Heavy metals (µg/L)
	Cr	Mn	Co	Ni	Cu	Zn	As	Cd	Pb
US-EPA (2008)	100	50	100	100	1300	5000	10	5	15
WHO (2008)	50	400	aNM	70	2000	NGLb	10	3	10

^aNM: not mentioned.

^bNGL: no guideline, because it occurs in drinking water at concentrations well below those at which toxic effects may occur.