Table 1.

Association between BPb and SPb for 2 New Orleans surveys completed in 2001 and 2017

Soil lead (SPb)	Census tracts (N)	Blood lead (BPb)	Census tracts (N)	Fisher’s exact test P value (ref. 35)
2001 Mdn SPb 99 mg/kg		2001 Mdn BPb 3.6 µg/dL
SPb ≥ 99 mg/kg	137	BPb ≥ 3.6 µg/dL	124
SPb < 99 mg/kg	137	BPb < 3.6 µg/dL	13	2.1 × 10−17
2017 Mdn SPb 54 mg/kg		2017 Mdn BPb 1.3 µg/dL
SPb ≥ 54 mg/kg	137	BPb ≥ 1.3 µg/dL	113
SPb < 54 mg/kg	137	BPb < 1.3 µg/dL	24	7.3 × 10−11

The median (Mdn) SPb decreased from 99 mg/kg to 54 mg/kg between 2001 and 2017. The Mdn BPb declined from 3.6 μg/dL to 1.3 μg/dL in the interval between the 2 SPb surveys. The small P values indicate that the decline in BPb is not unrelated to the decline in SPb.