Summary statistics relating to the concentration (ppm) of eight heavy metals measured across 1528 soil samples in Santa Ana, CA, and their associated state and federal screening levels (SLs)^a.

	Pb	As	Mn	Cr		Ni	Cu	Cd	Zn
Min	11.4	0.1	270.1	19.3		16.0	19.7	0.1	76.8
50th	77.8	6.6	646.9	61.2		37.5	56.4	1.4	266.9
Mean	123.1	8.3	663.4	64.9		38.7	67.6	1.7	328.0
Max	2687.0	174.8	8774.0	279.1		170.3	1950.0	23.9	3390.0
S.D.	181.3	9.3	236.0	20.3		9.7	79.6	1.4	233.3
Screening level (SL)				Cr(iii)	Cr(vi)
USEPA	400	0.68b	1800	120 000	0.3b	0.76b	3100b	71	23 000
CalEPA	80	0.07	—	100 000	0.3b	820	3000	1.7	23 000
% exceeding SLs
USEPA	3.9	91.1	<1	0	100	100	0	0	0
CalEPA	48.2	100.0	—	0	100	0	0	32.6	0

^aCalEPA SL values come from CalEPA human-exposure-based screening numbers developed to aid the estimation of cleanup costs for contaminated soil⁶⁰ while USEPA SL values come from USEPA's updated 2020 table of regional screening levels.⁶³

^bValue for carcinogenic outcomes.⁶³