Table 5. Average concentration of heavy metal (μg/g) of Cd, Pb, Cu, Fe, and Zn in the sediment during Northerly–Westerly monsoon in Bintan Island coastal water.

Cd = cadmium, Pb = lead, Cu = copper, Fe = iron, Zn = zinc.

Season	Location	Cd	Pb	Cu	Fe	Zn
Northerly monsoon	Malang Rapat	0.0029±0.0013	0.0504±0.015	0.0064±0.015	18.06±6.08	0.747±15.06
	Teluk Bakau	0.0056±0.0007	0.0327±0.0151	0.0371±0.014	14.28±6.64	26.61±15.3
	Beralas Pasir	0.0041±0.0006	0.0626±0.0145	0.0161±0.007	26.19±7.53	27.06±15.1
	Berakit	0.0053±0.001	0.0429±0.0063	0.0083±0.007	15.13±9.05	0.34±14.97
	Pengudang	0.0049±0.001	0.0341±0.0075	0.0230±0.007	11.80±9.36	26.25±14.97
	Sakera	0.0034±0.0011	0.0464±0.007	0.0109±0.0038	28.89±7.79	0.295±6.59
	Tg. Siambang	0.0054	0.0326±0.0093	0.008±0.0051	13.7±2.33	0.1281±6.33
	Average	0.0045±0.001	0.0431±0.011	0.0157±0.011	18.29±6.63	11.63±14.041
Easterly monsoon	Malang Rapat	0.0031±0.002	0.0512±0.017	0.0061±0.012	15.25±3.54	1.283±14.02
	Teluk Bakau	0.0072±0.0019	0.0231±0.021	0.0298±0.011	15.38±3.91	17.30±14.05
	Beralas Pasir	0.0034±0.001	0.0541±0.014	0.0261±0.010	21.45±5.48	29.24±15.95
	Berakit	0.0050±0.0009	0.0623±0.0146	0.0092±0.01	14.14±9.73	1.24±15.99
	Pengudang	0.0031±0.0014	0.0349±0.007	0.0277±0.01	10.72±9.71	28.49±16.29
	Sakera	0.0042±0.0008	0.0394±0.004	0.0251±0.08	29.03±7.83	0.34±6.28
	Tg. Siambang	0.0059±0.0039	0.0491±0.008	0.0092±0.06	14.22±1.5	0.193±2.83
	Average	0.0046±0.0015	0.0449±0.013	0.0190±0.0103	17.17±6.12	11.16±13.52
Southerly monsoon	Malang Rapat	0.012±0.048	0.0612±0.023	0.0058±0.029	16.39±0.52	2.195±12.27
	Teluk Bakau	0.0920±0.05	0.0170±0.031	0.0117±0.027	17.21±4.38	9.82±11.28
	Beralas Pasir	0.0041±0.0011	0.0271±0.025	0.0594±0.023	16.22±3.67	26.21±11.06
	Berakit	0.0051±0.0013	0.0762±0.026	0.0117±0.018	9.17±11.38	4.59±9.7
	Pengudang	0.0029±0.0015	0.0431±0.009	0.0390±0.020	14.52±9.31	19.48±10.46
	Sakera	0.0054±0.0072	0.0249±0.008	0.0463±0.019	31.01±8.6	1.24±4.57
	Tg. Siambang	0.0058±0.034	0.0386±0.018	0.0083±0.01	15.27±2.15	1.482±4.39
	Average	0.0182±0.032	0.0412±0.021	0.0260±0.021	17.11±6.67	9.29±9.904
Westerly monsoon	Malang Rapat	0.071±0.036	0.0712±0.029	0.0082±0.009	12.82±4.5	1.87±10.05
	Teluk Bakau	0.0921±0.045	0.0121±0.016	0.0162±0.035	19.87±4.45	9.26±8.12
	Beralas Pasir	0.0210±0.009	0.0411±0.04	0.0262±0.033	21.21±4.3	21.76±7.8
	Berakit	0.0065±0.002	0.0121±0.042	0.0825±0.029	12.92±7.54	6.53±7.82
	Pengudang	0.0021±0.002	0.0922±0.038	0.0245±0.010	18.27±6.24	17.23±8.87
	Sakera	0.0072±0.014	0.0262±0.008	0.0425±0.009	27.82±6.21	1.982±3.9
	Tg. Siambang	0.0022±0.013	0.0255±0.009	0.0244±0.004	16.07±1.21	1.726±4.49
	Average	0.0289±0.037	0.0401±0.031	0.0321±0.024	18.43±5.25	8.62±8.049

^*The residential areas: Malang Rapat, Teluk Bakau, Beralas Pasir, Pengudang, Sakera.

^** The ex-bauxsite mine: Tg. Siambang.