. 2023 Jan 12;11(1):73. doi: 10.3390/toxics11010073

Table 1.

Environmental stressors (physicochemical, metals, and pesticides) measured in water samples at the four study sites (S1 to S4) in the Conlara River (San Luis, Argentina) in the dry and wet seasons.

		Site				Site				Permitted Level in Human Drinking Water (µg/L) ^a	Permitted Level for Protection of Aquatic Life (µg/L) ^a
	Analytic Measurement	S1	S2	S3	S4	S1	S2	S3	S4
	Analytic Measurement	Dry Season				Wet Season
Physico Chemical	pH	8.77	8.42	9.01	7.86	8.92	7.66	7.81	7.85
	Conductivity (µS/cm)	349	434	1680	1814	216	509	2142	1847
	Nitrates (mg/L)	0.6	2.2	1.0	1.0	0.70	0.50	0.75	0.80	10,000	NL
	Nitrite (mg/L)	0.120	0.075	0.018	0.033	0.012	0.008	0.004	0.015	1000	60
	Amonia (mg/L)	0.04	0.13	0.60	0.60	0.21	0.36	0.16	0.19	50	1370
	Phosphate (mg/L)	0.028	0.021	0.023	0.028	0.012	0.185	0.020	0.062
	Total Hardness (mg CaCO₃/L)	176	180	468	484	61.45	136.8	529.1	471.9
	DO (mg 0₂/L)	11.23	10.16	10.16	8.32	8.50	6.22	9.26	8.93
	COD (mg 0₂/L)	3.58	3.87	2.72	2.58	1.40	1.40	1.26	1.55
	BOD (mg 0₂/L)	40.82	44.12	31.08	29.41	1.59	1.59	14.36	1.77
Metals (µg/L)	As	6.27	3.48	5.32	21.09	7.13	6.37	11.04	23.34	50	50
	Ba	59.96	50.12	45.47	37.97	15.26	60.67	72.80	27.61	1000	NL
	Cd	0.441	0.031	0.001	0.031	ND	ND	ND	ND	5	0.2
	Cu	465.6	395.9	344.6	380.0	28.53	27.76	24.05	33.73	1000	2
	Cr	5.59	1.81	1.49	2.56	82.02	52.60	52.46	57.83	50	2
	Fe	618.32	95.71	113.44	142.10	194.03	501.31	407.98	269.13	NL	NL
	Mn	49.91	54.27	41.97	183.97	484.77	271.21	183.48	15.71	100	100
	Pb	50.01	0.42	0.90	ND	2.62	1.90	2.55	2.25	50	1
	Zn	52.29	45.96	58.36	24.67	100.4	38.59	32.47	51.93	5000	30
Pesticides (µg/L)	α-BHC	0.020	BLQs	0.025	0.020	0.019	0.019	0.020	0.025	0.131	0.01
	Chlorpyrifos	BLQs	BLQs	BLQs	BLQs	0.167	0.079	0.079	0.050	90	0.083
	Permetrin	0.177	BLQs	0.233	0.146	0.101	BLQs	BLQs	0.057	NL	0.004 ^b
	Cypermethrin	0.271	0.108	0.322	0.183	0.132	0.108	0.116	0.107	NL	0.006
	Endosulfan α	BLQs	BLQs	0.107	BLQs	BLQs	BLQs	0.097	0.223	138	0.02
	Endosulfan β	0.222	BLQs	BLQs	BLQs	BLQs	BLQs	BLQs	BLQs		0.02
	Endosulfan sulfate	0.066	0.024	0.206	0.209	0.082	BLQs	BLQs	0.155		NL

BLQs: below limit of quantification. ND: not detected. NL: levels allowed by EPA or country regulations are not recorded. α-BHC: alpha-hexachlorocyclohexane. ^a Argentina normative based on EPA. ^b Canadian Water Quality. Guidelines for the Protection of Aquatic Life.