Figures & data
FIG. 1 Time series of BC from the environmental chamber experiment, showing just the three units that measured BC, one with an inlet with regular tubing, one with an inlet that included a “short” diffusion drier, and the third with an inlet that included a “long” diffusion drier (see text).
FIG. 2 (a) Time series of duplicate microAeth personal sampling with BC sources when the microAeth units were relatively new. Note that the enhanced levels of BC during time in the subway are probably caused by the abraded steel wheels which creates high concentrations of steel dust and airborne black iron oxides (Chillrud et al. Citation2004), which has significant absorption at the wavelength used by the microAeth. Due to the lower sensitivity to magnetite (Yan et al. 2011), as far as we are aware, it is only in the special microenvironment of enclosed subway tunnels that these black iron oxides obtain concentrations that can be recorded by the microAeth. (b) Time series of duplicate microAeth personal sampling after 17 months of heavy use. About 45-min of scripted physical movements, including walking, jumping, and running, were made during the suburban sampling when BC levels were near the limit of detection (0.1 μg/m3).
FIG. 3 (a) Time series of ΔRef and ΔSen patterns and BC readings corresponding to stationary behavior of microAeth. (b) Time series of ΔRef and ΔSen patterns and BC readings corresponding to 10-min hand-shaken (23:05–23:15).
FIG. 4 Time series of ΔRef and ΔSen patterns of the microAeth with only regular inlet tubing during the environmental chamber experiment shown in . The missing data (15 min) was due to time spent downloading this unit's data as an initial check on the BC levels in the chamber to check on whether the single filter could be predicted to last the entire experiment.
FIG. 5 The absolute value of the mean %difference between duplicate monitors for 19 duplicate deployments within the children's cohort, presented for different averaging times of the 5 min data. The absolute value of the mean is used to simplify the figure.
