Fig. 1
From: Geographic clustering of elevated blood heavy metal levels in pregnant women
Geospatial clustering of maternal blood metal concentrations. Measured maternal blood metal concentrations (as density, ng/g/km2 cluster analysis (Gi* p-value) for Cd, Hg, Pb, and As. Z-scores are calculated using the Hot Spot Analysis Tool and Getis-Ord statistics (Gi* = Z-score, p-value) with confidence level indicated by the Gi* p-value. Cluster confidence is reported using a heat map representation of p-values, with red indicating highest confidence (p < 0.01) in the existence of a geographic cluster