Phthalates and organophosphates in settled dust and HVAC filter dust of U.S. low-income homes: Association with season, building characteristics, and childhood asthma

Quantitative filter forensics with residential HVAC filters to assess indoor concentrations

“…Seasonal variation has been found to have an influence on fungal concentrations, albeit for culture‐based work . Of the OPEs, the particle‐bound concentration of TCPP in air is dominant during both summer and winter, which may due to the use of rigid PUFs in roof and wall insulations, with significantly higher concentrations in winter (Wilcoxon signed‐rank: P < 0.05 in Table S2). The differences in OPE concentrations in homes may relate to differences in product use, different airflow pathways through the building enclosure, and potentially different partition coefficients between the particle and the air phase in the two seasons.…”

“…A gravimetric analysis was used to measure the mass of dust collected on the HVAC filters. To this end, filters were pre‐conditioned in the laboratory and weighed prior to installation and post‐conditioned and weighed again after pickup from the sites . An analytical balance (Scout PRO 4000 g [OHAUS], resolution: 0.05 g) was used to weigh the filters.…”

“…Dust recovered from HVAC filters was processed and analyzed for different particle‐bound contaminants including total bacterial and fungal quantities, 36 fungal species panel, endotoxins, and SVOCs (six phthalates, five OPEs). Detailed methods for collecting and analyzing the biological and chemical contaminants of the HVAC dust in this study are provided in Maestre et al and Bi et al DNA‐based methods (eg, quantitative polymerase chain reaction [qPCR]) were used to characterize the non‐sieved biological contaminants captured on the HVAC filter. Bacterial 16S qPCR was conducted with a method modified from Harms et al, and fungal 18S qPCR was conducted with a method modified from Zhou et al It is noted that for the qPCR analysis, the non‐sieved samples contained both dust and large filter fibers.…”

“…Endotoxins were analyzed using a kinetic chromogenic method in the EM Lab P&K (an EMLAP‐certified laboratory) for sieved HAVC filter dust. Phthalates and OPEs were extracted from HVAC filter dust samples with hexane and analyzed using a GC‐FID system (Agilent 7890A, Santa Clara, CA, USA) equipped with a DB‐5ht column (30 m, 0.25 mm, 0.1 μm) . More detailed analytical methods for these SVOCs are available in Bi et al Phthalates include dimethyl phthalate (DMP), diethyl phthalate (DEP), di‐n‐butyl phthalate (DnBP), di‐n‐octyl phthalate (DnOP), benzyl butyl phthalate (BBzP), and di‐ethylhexyl phthalate (DEHP).…”

“…Phthalates and OPEs were extracted from HVAC filter dust samples with hexane and analyzed using a GC‐FID system (Agilent 7890A, Santa Clara, CA, USA) equipped with a DB‐5ht column (30 m, 0.25 mm, 0.1 μm) . More detailed analytical methods for these SVOCs are available in Bi et al Phthalates include dimethyl phthalate (DMP), diethyl phthalate (DEP), di‐n‐butyl phthalate (DnBP), di‐n‐octyl phthalate (DnOP), benzyl butyl phthalate (BBzP), and di‐ethylhexyl phthalate (DEHP). OPEs include tributyl phosphate (TnBP), tris (1‐chloro‐2‐propyl) phosphate (TCPP), tri (2‐butoxyethanol) phosphate (TBEP), triphenyl phosphate (TPhP), and tris (1,3‐dichloroisopropyl) phosphate (TDCPP).…”