A comparative study on arsenic fractions in indoor/outdoor particulate matters: a case in Baoding, China

The distribution and bioavailability of arsenic (As) in indoor/outdoor total suspended particulates (TSP), inhalable particulate matters (PM₁₀), and fine particulate matters (PM_2.5) in Baoding, China were investigated. The average I/O ratios for TSP, PM₁₀, and PM_2.5 were 0.52, 0.66, and 0.96, respectively. There was no significant correlation between indoor/outdoor TSP, PM₁₀, and PM_2.5. The indoor/outdoor concentrations of As surpassed the limited value of As. I/O ratios of arsenic in TSP, PM₁₀, and PM_2.5 were 0.52, 0.58, and 0.55, respectively. The contents of arsenic in different fractions were mainly affected by the total concentrations of arsenic in particulate matters (PM) rather than the particle sizes for TSP and PM₁₀. Arsenic was mainly in non-specifically sorbed fraction (F1) in both indoor and outdoor PM_2.5. The evaluated carcinogenic risk (CR) was within the safe level. The bioavailability of As increased with particle size decreasing for both indoor and outdoor PM. The potential bioavailability of As in outdoor particles was higher than that of indoor particles with the same size, especially PM_2.5.