(c).

Reference	Community	μgL−1
		As	Hg	Fe	Mn	Cd	Zn	Cr	Cu	Pb
Eastern region
Karikari and Ansa-Ansare 2006 [79]	Densu Basin covering Akwadum, Mangoase, Asuboi, Pakro and Ashalaja			964 (614–1190)	291 (264–337)		57 (14–100)		80 (28–274)	18 (<5–39)
Ansa-Asare and Asante 2000 [85]				61.4 (5–157)	60.7 (2–263)	1.4 (<1–2.6)	68.6 (1–89.2)			1.4 (0.1–2.6)
Boadu et al. 2000 [25]	Konongo and its surrounding areas: Odumase, Patriensa, Obenemase
	River Owerri	27.3 (13–43)
	River Awirekye	3.5
Nartey et al. 2005 [83]	Seven streams in the Akwapim Ridge (Otobri, Kobi, Opiafo, Amankrate, Kwati, Ademi, Elemi)			714.3	614.3		200
Central region
Dankwa and Biney 2005 [46]				2.09		<0.01				0.47
Donkor et al. 2006 [33]			20536
Fianko et al. 2007 [61]	Rivers supplying water to Iture Estuary
	Sorowie					4	180			6.45
	Kakum					3.2	200.1			2.65
Boamponsem et al. 2010 [29]	Kakum	1			145
Adokoh et al.   2011 [70]	Benya Lagoon	0.106	0.003		1.706	0.051
	Fosu lagoon		0.002		1.477	0.036
	Narkwa Lagoon	0.068	0.002		1.112	0.0425
Bentum et al.  2011 [86]	Fosu Lagoon			1150	2230		20.9		26.4
Tay et al. 2010 [80]	Greater Accra			1.65 (0.20)	0.942 (0.06)	0.006 (0.001)	0.113 (0.010)		0.268 (0.06)	0.02 (0.0)