Table 3.

Heavy metal concentration in effluents of 5 main drains of Hayatabad Industrial Estate, Peshawar.

Sites	Cd μg/L			Cr μg/L			Pb μg/L			Zn μg/L
	Min	Max	Avg	Min	Max	Avg	Min	Max	Avg	Min	Max	Avg
1	2	69	16	3	91	45	5	185	61	3	106	47
2	5	77	38	62	541	254	24	187	96	84	911	436
3	4	42	16	2	99	48	14	111	64	19	186	95
4	2	17	8	13	96	51	22	177	95	843	1904	1355
Control	1	19	8	15	71	40	11	99	46	12	84	43
WHO/FAO limits (2007) [38]	10 μg/L			100 μg/L			5000 μg/L			2000 μg/L
Pak-NEQSa [29]	100 μg/L			1000 μg/L			500 μg/L			5000 μg/L

^aValues represent maximum permissible limits of parameters according to Pak-NEQS (Pakistan National Environmental Quality Standards).