Fig. 2
From: Biological and behavioral factors modify urinary arsenic metabolic profiles in a U.S. population
Relations between arsenic concentrations in home tap water and primary and secondary methylation indices. Panel a shows the relation between home tap water arsenic levels and the primary methylation index. Arsenic concentrations in home tap water expressed as parts per billion (ppb, μg per l). Panel b shows the relation between home tap water arsenic levels and the secondary methylation index. The red line in each panel encloses 95 % of data