Assessment of groundwater quality, toxicity and health risk in an industrial area using multivariate statistical methods

Environmental Systems Research

Table 4 Descriptive Statistics of groundwater quality during summer and winter seasons

Parameters	Units	Range (summer)	Mean	Std. deviation	Skewness	Kurtosis	Range (winter)	Mean	Std. deviation	Skewness	Kurtosis	WHO limit (2014)	Igbah and Tanko (2019) (mean)
pH	pH	6.4–8.1	7	0.4	0.8	0.7	6.4–7.8	6.9	0.3	0.7	0.9	6.5–8.5	6.75
TDS	mg/L	620–4361	1875	819	1.0	0.7	445–2829	1527	552	0.5	− 0.2	1000	1068
EC	µs/cm	1.0–7.6	3	1	0.7	0.5	1.11–7.25	3.3	1	0.7	0.11	1500	1796
Ca²⁺	mg/L	88–2477	655	430	1.8	5.2	84–1584	569	316	0.9	0.8	300	66.6
Mg²⁺	mg/L	2.0–286	59	69	2.0	3.5	2.3–256	56	62	1.8	3	50	83.4
Na⁺	mg/L	31.0–1012	340	253	1.1	0.2	27–563	211	133	1	0.7	50	260
K⁺	mg/L	0.6–21	5	3.3	3.0	12	1.10–9	4	2	0.8	1.3	12	6.15
CO₃²⁻	mg/L	32–321	148	65	1.0	0.2	30–269	126	54	1	0.7	NA	19.5
HCO₃⁻	mg/L	66–765	301	189	1.0	0.0	63–765	228	123	2	5	500	481
Cl⁻	mg/L	84–1181	289	187	2.4	9.2	35–896	223	132	3	12	250	236
F⁻	mg/L	0.10–1.20	0.5	0.3	1.0	0.3	0.09–23	0.85	3	7	51	1.5	1.28
SO₄²⁻	mg/L	9.2–493	99	86	2.5	8.4	6.3–305	86	66	2	3	250	447
NO₃⁻	mg/L	6.0–75	28	16	0.7	0.1	4.4–66	23	14	1	0.5	50	4.20
As	µg/L	1.0–62	18	19	1.1	− 0.3	1.09–12	4	2	2	5	10
Cd	µg/L	0.20–7	2	1.5	2.0	4	0.04–6	0.4	1	5	19	5
Cr	µg/L	6.4–217	29	32	4.3	25	0.47–10	5	3	− 0.2	− 1.6	50
Cu	µg/L	1.4–200	17	29	5.3	32	0.92–18	4	3	2	6	2000
Ni	µg/L	1.2–76	25	19	1	− 0.3	0.11–38	6	7	3	7	70
Pb	µg/L	0.4–454	82	102	2	3	0.09–45	3	7	5	27	10
Zn	µg/L	34–5818	953	1091	2	7	16–22036	989	4241	5	23	3000