From air to clothing: characterizing the accumulation of semi-volatile organic compounds to fabrics in indoor environments

Abstract

Uptake kinetics of semi-volatile organic compounds (SVOCs) present indoors, namely phthalates and halogenated flame retardants (HFRs), were characterized for cellulose-based cotton and rayon fabrics. Cotton and rayon showed similar accumulation of gas- and particle-phase SVOCs, when normalized to planar surface area. Accumulation was 3-10 times greater by rayon than cotton, when normalized to Brunauer-Emmett-Teller (BET) specific surface area which suggests that cotton could have a longer linear uptake phase than rayon. Linear uptake rates of eight consistently detected HFRs over 56 days of 0.35-0.92 m /day.dm planar surface area and mass transfer coefficients of 1.5-3.8 m/h were statistically similar for cotton and rayon and similar to those for uptake to passive air sampling media. These results suggest air-side controlled uptake and that, on average, 2 m of clothing typically worn by a person would sequester the equivalent of the chemical content in 100 m of air per day. Distribution coefficients between fabric and air (K') ranged from 6.5 to 7.7 (log K') and were within the range of partition coefficients measured for selected phthalates as reported in the literature. The distribution coefficients were similar for low molecular weight HFRs, and up to two orders of magnitude lower than the equilibrium partition coefficients estimated using the COSMO-RS model. Based on the COSMO-RS model, time to reach 95% of equilibrium for PBDEs between fabric and gas-phase compounds ranged from 0.1 to >10 years for low to high molecular weight HFRs.

Partitioning of PCBs from air to clothing materials in a Danish apartment

“…The partition coefficients observed here for 100% cotton materials are similar to those reported by Morrison et al and Cao et al for di‐n‐butylphthalate (DnBP; log 10 K vol = 6.6, 6.1), lower than distribution coefficients reported by Saini et al for DnBP, di‐isobutyl phthalate (DiBP), or diethylhexylphthalate (DEHP) (log 10 K vol = 6.8, 7.2, and 7.4, respectively) but higher than those reported for diethylphthalate (log 10 K vol = 5.7) or methamphetamine (log 10 K vol = 5.7) . These, and additional literature data that were reported to be at or near equilibrium, are plotted against the octanol‐air partition coefficient ( K oa ) in Appendix S7 (Figure A.7.1).…”

“…In addition to the stable mass accumulated, Log 10 ( K area ) at 7 days ranges over >1 order of magnitude. If the materials were still far from equilibrium, we would anticipate that the area normalized partition coefficients would be similar, that is, the uptake rate during the first 7 days would be similar among samples due to mass‐transport resistance from bulk air to fabric surfaces …”

“…Models that predict the impact of clothing on dermal uptake have been developed but require knowledge of the sorptive capacity of the clothing and its exposure history prior to being worn. Accumulation of organic compounds with clothing fabrics has been quantified using laboratory chambers, inferred from dynamic uptake experiments and from fabrics exposed to air in an office . The latter method best assesses the accumulation under real‐world environmental conditions.…”

Dermal uptake of phthalates from clothing: Comparison of model to human participant results

“…Computational methods may also allow for estimating partition coefficients for those SVOC‐fabric pairs that have not been investigated experimentally . Goss applied several computational methods to estimate K cellulose‐water and found that their results correlated well with most measurements reported by Hung et al .…”

“…As these estimates are based on values obtained in water, the cellulose should be considered "fully hydrated." In air, the cellulose in cotton would be less than fully hydrated and resulting partition coefficients for low-polarity compounds like DEP and DnBP may be somewhat higher.Computational methods may also allow for estimating partition coefficients for those SVOC-fabric pairs that have not been investigated experimentally 29. Goss 30 applied several computational methods to estimate K cellulose-water and found that their results correlated well with most measurements reported by Hung et al28 Note that DEP and DnBP were excluded from their correlation because their predictions deviated significantly from the Hung et al28 results.…”