Assessing Heavy Metals Accumulation in the Leaves and Sediments of Urban Mangroves (Avicennia marina (Forsk.) Vierh.) in Bahrain

Table 2

Mean concentrations of heavy metals in mg L⁻¹ (±SEM) () in the sediment of gray mangrove .

Site	Depth (cm)/metals	Cr	Cu	Fe	Mn	Ni	Pb	Zn
Tubli	0–5	27.3	85.7	4521.5	86.4	7.7	26.2	110.7
	5–15	24.1	65.7	3597.0	81.7	7.0	22.1	82.4
	15–30	17.2	17.5	2646.1	70.9	3.3	15.5	32.9
Sitra (1)	0–5	18.8	21.5	3920.0	71.1	6.00	15.2	35.5
	5–15	18.9	13.1	3675.7	71.7	5.3	13.3	24.1
	15–30	18.2	11.9	3425.4	63.4	6.2	12.97	21.2
Sitra (2)	0–5	16.9	16.6	3542.5	59.7	4.4	16.2	36.3
	5–15	16.2	13.3	3336.6	57.4	5.3	18.0	37.7
	15–30	11.8	11.02	2319.3	35.1	1.9	17.2	22.4
Dehghani and Karbassi (2015)		—	30.11	1894	—	25.08	43.70	—
Einollahipeer et al. (2013)		—	42.13	—	—	54.12	47.90	43.61
NOAA		81	34	—	—	21	46	150
Canadian (ISQGs)		52	18				30	124
EPA
Nonpolluted		<25	<25	—	—	<20	<40	<90
Slightly polluted		25–75	25–50	—	—	20–50	40–60	90–200
Severely polluted		>76	>50	—	—	>50	>60	>200

in the same column not connected with the same letter are significantly different (). Mo concentration in mangrove sediment was less than 0.001 mg L⁻¹; NOAA (1997 revision), http://www.esd.ornl.gov/programs/ecorisk/documents/tm95r4.pdf; Canadian (ISQGs), https://www.elaw.org/system/files/sediment_summary_table.pdf; US EPA, 1991. Sediment quality guidelines. Draft report. EPA Region V Chicago IL.