Toxic Metals Enrichment in the Surficial Sediments of a Eutrophic Tropical Estuary (Cochin Backwaters, Southwest Coast of India)

Table 4

Comparison of heavy metal levels (ppm) in the Cochin backwaters to that of other Indian and globally impacted coastal systems.

Location	Zn	Cd	Pb	Cu	References
Continental crustal average	52	0.1	14.8	104	[44]
Cochin estuary	10.0–2233.0	0.2–40.7	6.8–99.6	3.6–123.5	Present study
Cochin estuary	592–1266.0	6.2–14.9	39.9–71.3	32.4–53.2	[10]
Mumbai harbour, India	155	—	48	105	[45]
Ganges estuary, India	611	—	115	53	[46]
Bilbao estuary, N. Spain	1092	—	314	263	[47]
Humber estuary, UK	319	—	127	70	[48]
Solway estuary, Scotland	59	—	25	7	[49]
Forth estuary, Scotland	150	—	89	86	[50]
Thames estuary, UK	219–1050	1.3–9.8	179–1634	61–348	[51]
Port Phillip Bay, Victoria	—	2.37	43.5	25.0	[52]
New South Wales estuary, Australia	—	1.60	21.0	6.0	[53]
New York Harbor (USA)	188–244	1-2	109–136	105–131	[54]
Bremen Harbor (Germany)	790	6.0	122	87	[55]
Izmir Harbor (Turkey)	182	6.2	97	182	[56]
Rhine estuary (Germany)	2900	45	800	600	[57]