Table 2.

Difference in the mean concentration of titanium, nickel vanadium and arsenic in the three groups.

Multiple Comparisons
Tukey’s HSD
Dependent Variable	(I) Groups	(J) Groups	Mean Difference (I-J)	Std. Error	Sig.	95% Confidence Interval
						Lower Bound	Upper Bound
Titanium	Group C	Group A	−352.951280 *	59.517272	0.000	−494.61555	−211.28701
		Group B	−356.184613 *	61.127007	0.000	−501.68041	−210.68882
	Group A	Group C	352.951280 *	59.517272	0.000	211.28701	494.61555
		Group B	−3.233333	69.678791	0.999	−169.08426	162.61760
	Group B	Group C	356.184613 *	61.127007	0.000	210.68882	501.68041
		Group A	3.233333	69.678791	0.999	−162.61760	169.08426
Nickel	Group C	Group A	−20.215246 *	2.410887	0.000	−25.95369	−14.47680
		Group B	−18.728483 *	2.476093	0.000	−24.62213	−12.83483
	Group A	Group C	20.215246 *	2.410887	0.000	14.47680	25.95369
		Group B	1.486763	2.822503	0.858	−5.23142	8.20494
	Group B	Group C	18.728483 *	2.476093	0.000	12.83483	24.62213
		Group A	−1.486763	2.822503	0.858	−8.20494	5.23142
Vanadium	Group C	Group A	−0.965529	0.809320	0.460	−2.89189	0.96083
		Group B	−0.707260	0.831209	0.672	−2.68572	1.27120
	Group A	Group C	0.965529	0.809320	0.460	−0.96083	2.89189
		Group B	0.258269	0.947497	0.960	−1.99698	2.51352
	Group B	Group C	0.707260	0.831209	0.672	−1.27120	2.68572
		Group A	−0.258269	0.947497	0.960	−2.51352	1.99698
Arsenic	Group C	Group A	−2.193412 *	0.336286	0.000	−2.99385	−1.39298
		Group B	−1.525553 *	0.345382	0.000	−2.34764	−0.70347
	Group A	Group C	2.193412 *	0.336286	0.000	1.39298	2.99385
		Group B	0.667859	0.393701	0.212	−0.26924	1.60496
	Group B	Group C	1.525553 *	0.345382	0.000	0.70347	2.34764
		Group A	−0.667859	0.393701	0.212	−1.60496	0.26924

* The mean difference is significant at the 0.05 level. HSD, honestly significant difference.