Fig. 6
Association of cytotoxic potency in J774A.1 cells with metal content in size-fractionated particles. Cytotoxic potencies according to lactate dehydrogenase (LDH) release and resazurin reduction were regressed against total, water-soluble, and non-water-soluble metals. Pearson product–moment correlation coefficient r-values are presented. LDH release. a Total metals. UFP, r = 0.83, p = 0.08; PM0.1–2.5, r = 0.67, p = 0.22; PM2.5–10, r = 0.92, p = 0.03; PM>10, r = 0.91, p = 0.03. b Water-soluble metals. UFP, r = 0.36, p = 0.55; PM0.1–2.5, r = 0.96, p < 0.01; PM2.5–10, r = 0.33, p = 0.59; PM>10, r = 0.92, p = 0.02. c Non-water-soluble metals. UFP, r = 0.96, p = 0.01; PM0.1–2.5, r = 0.48, p = 0.42; PM2.5–10, r = 0.93, p = 0.02; PM>10, r = 0.91, p = 0.03. Resazurin reduction. d Total metals. UFP, r = −0.86, p = 0.06; PM0.1–2.5, r = −0.70, p = 0.19; PM2.5–10, r = −0.92, p = 0.02; PM>10, r = −0.75, p = 0.15. e Water-soluble metals. UFP, r = −0.75, p = 0.14; PM0.1–2.5, r = -0.77, p = 0.13; PM2.5–10, r = −0.31, p = 0.61; PM>10, r = −0.84, p = 0.07. f Non-water-soluble metals. UFP, r = −0.69, p = 0.20; PM0.1–2.5, r = −0.60, p = 0.28; PM2.5–10, r = −0.94, p = 0.02; PM>10, r = −0.74, p = 0.15