Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2017 Aug 24;125(8):087017. doi: 10.1289/EHP1265

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted.

PMC Copyright notice

Presence-absence map showing combinations of Group C chemicals, which include (C1) pyrethroids, herbicides, et al.; (C2) polyfluoroalkyl chemicals; (C3) caffeine and metabolites; and (C4) DEET and metabolites. — Presence–absence map (black indicates present) illustrating 36 maximal prevalent combinations of Group C chemicals (rows 1 through 36) and one supercombination consisting of 27 of the 40 chemicals in Group C (row 37). The maximal prevalent combinations were identified using frequent item set mining (FIM) with discretization thresholds set at the 50th percentiles and a minimum prevalence level of 40%. The supercombination occurred in 2 Subsample C subjects, representing a total of 479,033 (or 0.21%) of 226,021,580 represented U.S. residents. NHANES codes along the top of the figure indicate Group C chemicals, and these are organized into subgroups C1, C2, C3, and C4. The observed prevalence number at the right of each row indicates the proportion of U.S. residents in which the given combination was observed to occur.