Ultra compact multi-channel particle sampler for personal exposure of particle chemical composition at hourly...

Hourly-resolution chemical characterization of PM_2.5 exposure remains a significant challenge in exposure science, despite its critical importance for accurate health impact assessment. Current literature predominantly focuses on daily or annual PM_2.5 metrics, as conventional sampling methods typically require extended collection periods to accumulate sufficient mass for chemical analysis. This study introduces the Personal Exposure Sampler (PES), a compact and portable device for personal PM_2.5 exposure assessment. It enables high-temporal resolution measurements and chemical speciation. This innovative sampler employs a sequential sampling mechanism that alternates among six sampling spots on a single 47 mm filter, enhancing particle collection efficiency for analysis while maintaining portability for personal exposure studies. Laboratory validation confirmed the impactor effectively achieved a 2.5  μm aerodynamic cut off. In parallel, chamber tests using nebulized NaCl particles showed strong agreement between the PES and a federal reference method (FRM) sampler, with a correlation coefficient of R² = 0.99. Field tests demonstrated excellent agreement with FRM samplers, with micro-synchrotron radiation X-ray fluorescence analysis for six metals (R² = 0.88) and gas chromatography (GC) coupled with a temperature-programmable inlet and time-of-flight mass spectrometry (ToF-MS) for five polycyclic aromatic hydrocarbons (PAHs) (R² = 0.85). A pilot study with participants following different activity patterns revealed distinct exposure profiles across various microenvironments at hourly resolution, which conventional personal exposure sampling cannot achieve. This technology addresses a critical gap in personal exposure instrumentation, improving our understanding of the health impacts of specific PM constituents and their temporal variability.