Table 2.

The summary of the mean heavy metal concentrations in µg L⁻¹ at the lower basin of the Danube River, Hungary

	Period	As	Cr	Cu	Fe	Mn	Ni	Pb	Zn
S1	April–Sep	1.21	1.45	4.29	626.8	55.26	2.55	1.22	16.45
	Oct–March	1.30	1.07	3.33	405.5	38.88	2.41	0.93	14.35
S2	April–Sep	1.27	1.3	4.17	518.3	48.26	2.64	1.61	14.78
	Oct–March	1.27	0.93	3.37	336.1	44.78	2.29	1.37	14.44
S3	April–Sep	1.34	1.42	4.4	634.73	55.26	2.64	1.42	17.66
	Oct–March	1.45	1.01	3.71	452.9	34.37	2.71	1.03	16.25
S4	April–Sep	1.35	1.8	3.48	170.67	40	3.1	1.14	12.93
	Oct–March	1.28	1.58	3.81	208.3	26	2.45	1.3	12.79
S5	April–Sep	1.37	1.11	3.74	436.76	43.42	2.87	1.2	11.98
	Oct–March	1.46	1.42	3.62	381.2	31.91	2.3	1.12	16.13
S6	April–Sep	1.20	1.49	4.11	590.5	72.1	2.86	1.45	14.38
	Oct–March	1.70	1.83	3.79	511	65.71	2.6	1.55	15.8
S7	April–Sep	1.31	1.44	4.03	666.67	56.84	2.27	1.14	16.8
	Oct–March	1.60	1.65	4.17	528.5	36.3	2.8	1.34	19.39
EU-Directive-2020/2184 (The European Parliament and the Council of the European Union 2020)		10	25.0	2000	200	50	20	10	_
WHO-2017 (WHO, 2017)		10	50.0	3000	300	50	70	10	1000

Bold values indicate that they have exceeded the given standards of EU and WHO