Measurement of Polycyclic Aromatic Hydrocarbons (PAHs) on Indoor Materials: Method Development

Recycling process of decoration and demolition waste is a neglected source for emerging concerns in particulate phase: PAHs as an example

Decoration and demolition waste (DDW) has been widely studied because of its annual surge in output, complex composition, and high utilization potential. DDW recycling is a key element of circular economy, with the potential for emerging pollutants in the particulate phase. Thus, this study selected polycyclic aromatic hydrocarbons (PAHs) as the representative and investigated their emission characteristics and occupational risk in the particulate phase, including 2.5-μm (PM2.5), inhalable (PM10), total suspended particles (TSP), and dust samples of different sizes (75-100 μm, 50-75 μm, and < 50 μm), from dust collectors during DDW recycling. Acenaphthylene (Acy), chrysene (Chr), benz[a]anthracene (BaA), fluoranthene (Fla), pyrene (Pyr), phenanthrene (Phe) were detected in all samples. PM2.5 and dust in 75-100 μm own the highest total occupation risk of 1.51 × 10-13 and 2.07 × 10-15, respectively. Chr and BaA had the control priority with the converted toxicity of 162.82 ng/g and 233.35 ng/g. Moreover, nontarget screening was applied to mining out isophorone, benzophenone, and other carcinogenic micropollutants in the PM2.5, PM10, TSP, and dust samples. Global PAHs from DDW recycling production can reach 193.44 ± 241.80 kg/a under reasonable estimation. This study provides strong evidence that DDW recycling is a neglected source of concern in the particulate phase.

Comprehensive methodology for semi-volatile organic compound determination in ambient air with emphasis on polycyclic aromatic hydrocarbons analysis by GC-MS/MS

Polycyclic aromatic hydrocarbons are air pollutants that affect the human health and the environment, and their accurate determination in outdoor and indoor environments is important. This study presents a methodology for sampling and analysis of semi-volatile compounds in ambient air with emphasis on the polycyclic aromatic hydrocarbons, collected with low-volume pumps (4.8 m3) in unconditioned solid phase extraction cartridges (Isolute ENV+). Sampling in SPE cartridges with low-volume pumps allows the collection of both gas and particulate phase compounds in indoor as well as outdoor environments, and reduces the number of extraction steps required as well as the solvent volume used for extraction. Analysis of the 16 US-EPA priority PAHs after extraction was conducted by GC-MS/MS with recoveries of the PAHs 40-118 %. No breakthrough was detected during sampling. Moreover, the methodology includes storage test to assess the conservation of PAHs in the SPE cartridges in heat-sealable Kapac bags; simulating transport from sampling sites to laboratory, and storage under room, cold and frozen conditions at different time-intervals, up to 3 months after sampling. The results showed that concentration levels remained constant across various storage time intervals and temperatures, with naphthalene and acenaphthylene being the only exceptions, showing high blank levels for the first and losses at room temperature for the later. The method quantification limits, including sampling, storage and GC-MS/MS analysis ranged from 2000 pg m-3 for naphthalene and 300 pg m-3 for phenanthrene to less than 20.0 pg m-3 for higher molecular and less volatile PAHs, such as benzo[a]pyrene (LOQ = 8.0 pg m-3). The feasibility of the method was tested by sampling indoors under urban background air conditions, showing individual PAH concentrations 4 to 10 times higher than their method quantification limits.

Polycyclic Aromatic Hydrocarbons (PAHs) in Wildfire Smoke Accumulate on Indoor Materials and Create Postsmoke Event Exposure Pathways

Wildfire smoke contains PAHs that, after infiltrating indoors, accumulate on indoor materials through particle deposition and partitioning from air. We report the magnitude and persistence of select surface associated PAHs on three common indoor materials: glass, cotton, and mechanical air filter media. Materials were loaded with PAHs through both spiking with standards and exposure to a wildfire smoke proxy. Loaded materials were aged indoors over ∼4 months to determine PAH persistence. For materials spiked with standards, total PAH decay rates were 0.010 ± 0.002, 0.025 ± 0.005, and 0.051 ± 0.009 day-1, for mechanical air filter media, glass, and cotton, respectively. PAH decay on smoke-exposed samples is consistent with that predicated by decay constants from spiked materials. Decay curves of smoke loaded samples show that PAH surface concentrations are elevated above background for ∼40 days after the smoke clears. Cleaning processes efficiently remove PAHs, with reductions of 71% and 62% after cleaning smoke-exposed glass with ethanol and a commercial cleaner, respectively. Laundering smoke-exposed cotton in a washing machine and heated drying removed 48% of PAHs. An exposure assessment indicates that both inhalation and dermal PAH exposure pathways may be relevant following wildfire smoke events.