Assessment and characterization of ambient indoor particulate matters using aerosol monitor, inductively coupled plasma mass spectrometry, and transmission electron microscopy

In this work, we studied the levels of ambient indoor particulate matters in some work premises of Al-Ain city during the months June–July 2013. Work premises included United Arab Emirates University (UAEU) campus, hospitals, and schools. We also studied the chemical composition and morphology of collected particulate matters using inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscope (TEM). Our results indicated average total concentrations less than 50.00 μg/m³ for PM_1.0, PM_2.5, PM_4.0, plus PM_10.0 in closed sites. Sites crowded with customers coming in and out such as entrances of hospitals and municipality gave average total concentrations in the range 160.0–200.0 μg/m³. Higher average total concentrations were found in sites with high outdoor air exchange. Particulate matters in the city ambient air originate from neighboring deserts and mountain and carried out by storms covering the country for different time intervals over the year. Correlation between the levels of particulate matters (PMs) and metrological parameters during the time of study was found insignificant. ICP-MS elemental analysis of collected particulate matters revealed sulfur and silicon-based particles containing significant amounts of calcium, sodium, boron, aluminum, magnesium, potassium, and chlorine. TEM imaging of collected particles showed clusters of crystalline and amorphous particulates corresponding to the silicate and sulfate matrices, respectively. Although the levels we recorded for particulate matters are generally in accordance with the United Arab Emirates and WHO standards for indoor PMs, our findings are important since long exposures to silicate and sulfate particles represent high risk factors on public health.