Table 5.

Multiple regression analysis of Cr (VI), oxidic Ni, and soluble Ni concentrations corresponding to significant independent variables

Dependent variable	Independent variables	β	SE	p-value	R2
(1) Log (Cr (VI) concentration, μg/m3) = –0.508 + 0.239 χ1 + 0.101 χ2 (2) Log (oxidic Ni concentration, μg/m3) = –1.247 + 0.293 χ1 + 0.542 χ2 (3) Log (soluble Ni concentration, μg/m3) = –1.047 + 0.103 χ1 + 0.285 χ3 (4) The percentage of Cr or Ni content in the filler welding on stainless steel (SS) with the SMAW method. (5) The percentage of Cr or Ni content in the filler welding on stainless steel (SS) with the GTAW method. (6) The percentage of Cr or Ni content in stainless steel (SS) base metal. Abbreviations: Cr: chromium; Ni: nickel; SE: standard error; R2: R-squared value.
Cr VI concentration (1)	Intercept	–0.508	0.086	<0.05	0.96; 0.93 (adjusted)
	χ1 (filler of SMAW-SS) (4)	0.239	0.007	<0.05
	χ2 (filler of GTAW-SS) (5)	0.101	0.013	<0.05
Oxidic Ni concentration (2)	Intercept	–1.247	0.095	<0.05	0.95; 0.90 (adjusted)
	χ1 (filler of SMAW-SS)	0.293	0.011	<0.05
	χ2 (filler of GTAW-SS)	0.542	0.030	<0.05
Soluble Ni concentration (3)	Intercept	–1.047	0.095	<0.05	0.95; 0.90 (adjusted)
	χ1 (filler of SMAW-SS) (6)	0.103	0.017	<0.05
	χ3 (base metal of SS)	0.285	0.013	<0.05