Dust Dynamics: Distribution Patterns of Semi-Volatile Organic Chemicals across Particle Sizes in Varied Indoor Microenvironments

Abstract

An extensive analysis of the distribution patterns of three distinct classes of semi-volatile organic chemicals (SVOCs)—phthalates (PAEs), organophosphate flame retardants (OPFRs), and polycyclic aromatic hydrocarbons (PAHs) — across four discrete size fractions of dust (25, 50, 100, and 200 μm) was conducted. The dust samples were sourced from AC filter, covered car parking lots, households, hotels, mosques, and car floors. To generate the four fractions, ten dust samples from each microenvironment were pooled and sieved utilizing sieving apparatus with the appropriate mesh size. Selected SVOCs were quantified utilizing gas chromatography-mass spectrometry in electron impact (EI) mode. Results revealed varying degree of contamination with dust fractions from car parking lots dust showed the lowest chemical contamination, while car floor dust was the most contaminated. SVOCs concentrations exhibited a tendency to increase as the size of dust particles decreased, particularly evident in car floor and car parking lot dust across the microenvironments analyzed. Among SVOCs, PAEs emerged as the predominant contributors with >90% followed by OPFRs and PAHs. Among analyzed microenvironments, car floor dust exhibited the highest levels of PAHs and OPFRs, this align logically with the fact that numerous interior components of cars are treated with OPFRs to adhere to fire safety regulations. Furthermore, petroleum products are a major source of PAHs in the environment and all the sampled cars in the study had combustion engines. Consequently, car dust is more likely to be polluted with PAHs stemming from petroleum combustion. Heavy metals and brominated flame retardants have increased with decreasing dust particles in a few investigations, however, this is the first study analyzing these SVOCs in different fractions of dust from various microenvironments. However, aside from two specific microenvironments, the observed pattern of escalating SVOC concentrations with smaller dust particle sizes was not corroborated among the examined microenvironments. This divergence in concentration trends suggests the potential involvement of supplementary variables in influencing SVOC distributions within dust particles.