Table 3.

Pearson correlations (r_p) between the natural logarithm of underground area air measurement results for REC and other DE components, overall and by mining facility

DE component	rp, n
	All facilities	Limestone	Potash		Salt	Trona
		Facility A	Facility B	Facility D	Facility E	Facility G	Facility H	Facility I
EC measurements (μg m−3)
REC	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00
TEC	0.92, 174	0.98, 26	0.99, 23	0.95, 19	0.94, 26	0.77, 23	0.87, 25	0.83, 29
SEC	0.94, 162	0.97, 24	0.97, 24	0.90, 18	0.93, 25	0.77, 26	0.93, 20	0.90, 28
OC measurements (μg m−3)
TOC	0.44, 174	0.73, 26	0.45, 23	0.58, 19	0.87, 26	0.30, 26	0.54, 25	0.67, 29
ROC	0.67, 176	0.79, 26	0.71, 24	0.95, 19	0.95, 26	0.41, 26	0.59, 26	0.59, 29
SOC	0.22, 165	0.84, 24	0.73, 24	0.52, 19	0.92, 26	−0.24, 23	0.53, 20	0.39, 29
Gaseous measurements (ppm)
NO	0.72, 176	0.41, 26	0.78, 24	0.86, 19	0.96, 26	0.70, 26	0.91, 26	0.61, 29
NO2	0.52, 168	0.30, 26	0.50, 24	0.63, 19	0.92, 26	0.01, 26	0.28, 26	0.31, 29
CO	0.41, 168	0.49, 23	0.77, 23	0.62, 19	0.74, 26	0.44, 23	0.40, 25	0.05, 29
CO2	0.66, 162	0.70, 26	0.84, 17	0.84, 14	0.89, 26	0.46, 24	0.76, 26	0.24, 29
Particulate measurements (mg m−3)
TD	0.27, 175	0.56, 26	−0.02, 23	0.64, 19	0.68, 26	0.48, 26	0.43, 26	0.39, 29
RD	0.56, 170	0.65, 25	0.28, 24	0.79, 18	0.90, 26	0.51, 25	0.32, 25	0.36, 27
SMDa	0.79, 92	0.22, 22	0.53, 24	NA	0.48, 26	NA	0.29, 20	NA
SCD	0.69, 162	0.10, 22	0.85, 24	0.48, 19	0.86, 26	0.49, 23	0.59, 20	0.45, 28

n = number of measurements; NA = not applicable.

^aFor three facilities the SMD filters were not re-weighed before the SCD analysis and therefore SMD is missing for Facilities D, G, and I.