A statistically significant enrichment of hypomethylated sites was observed when comparing cord blood plasma DNA methylation from individuals A) residing in a high air pollution region (south Durban) compared with the low pollution north Durban and B) with maternal HIV exposure compared with uninfected mothers. Relationships were assessed in models adjusting for gestational age, child’s sex, air pollution group, and maternal HIV status (n=22). Percentage of hypomethylated (direction=negative) and hypermethylated (positive) sites are displayed from the following groups of CpG sites: 1) all sites (n=433,782), 2) p<0.001 (n=420 for air pollution, 689 for HIV), or effect size >1 (log fold-change <−1 or >1; n=781 for air pollution analysis, 514 for HIV). A reference line is drawn at 50%.