Assessing indoor air exposures using passive sampling with bioanalytical methods for estrogenicity and aryl hydrocarbon receptor activity

Abstract

Passive air sampling was undertaken using polyurethane foam passive air samplers at three types of locations, including indoors (six offices) at buildings in the central business district (CBD) and at a private suburban home (indoor and outdoor) located 9 km from the CBD in Brisbane, Queensland, Australia. Estrogenic (E-SCREEN—MCF7-BOS) and aryl hydrocarbon receptor (AhR) (CAFLUX— H4G1.1c2) activity were assessed for samples collected from each of these locations. The samples were tested either as crude extracts (“untreated”) or were subjected to H2SO4 silica gel (“treated”) for each location in order to determine whether chemicals, which are not resistant to this treatment like polycyclic aromatic hydrocarbons, potentially account for the observed activity. In most cases, H2SO4 treatment resulted in a statistically significant reduction of potency for both endpoints, suggesting that chemicals less resistant to treatment may be responsible for much of the detected biological activity in these locations. Estrogenic potency measurements (<0.22–185 pg m−3) were highest in the indoor offices, followed by the indoor suburban home and finally the outdoor suburban home (which was not estrogenic). Total AhR activity for crude extracts (1.3–10 pg m−3) however was highest for the outdoor suburban home site. Levels of polycyclic aromatic hydrocarbons were monitored indoors and outdoors at the suburban home. At that location, polycyclic aromatic hydrocarbon air concentrations were on average approximately two times higher outdoor than indoor, while AhR potency was five times higher outdoor than indoor. No significant correlation was found between the estrogenic and AhR activity (P=0.88) for the sites in this study.

Effect based monitoring of seasonal ambient air exposures in Australia sampled by PUF passive air samplers

“…Where passive samplers such as PUF or semipermeable membrane devices have been used to monitor PAH in either ambient (Cupr et al, 2006) or indoor and outdoor air in an occupational exposure setting (coke plant) (Bonetta et al, 2009), the highest genotoxic effects are associated with locations where the highest PAH levels have been accumulated by these samplers. Similarly, we previously determined that differences in the potency of AhR activity in indoor vs. outdoor air sampled by PUF passive air samplers reflected potential PAH profiles, although many of the carcinogenic PAHs were not detected (Kennedy et al, 2009). Together these results indicate that passive samplers may provide a convenient means of conducting effect based monitoring consistent with PAH exposures and with results derived from more traditional active sampling of ambient air.…”

“…For the winter BIO-PUF samples only, 10% of the extract was solvent exchanged to hexane and treated overnight with H 2 SO 4 /silica gel (Kennedy et al, 2009) before rotary evaporation/solvent exchange to ethyl acetate and then evaporation/solvent exchange to a final volume of 12 μL in DMSO for assessment on the CAFLUX. This treatment step was incorporated in order to quantify the proportion of “total” AhR activity (determined by testing of remaining untreated proportion of each extract in a final volume of 108 μL) that is potentially accounted for by dioxin-like HAHs, which are resistant to this treatment.…”

“…Cell growth and seeding is described in more detail in SM and the testing protocol has been described in detail previously (Kennedy et al, 2009). In brief for dosing, the media was replaced with 100 μL of non-selective media containing in triplicate the BIO-PUF sample (5 point, 10-fold dilution series, maximum 1% DMSO), the reference compound (TCDD) dilution series (9 point, 2×10 -7 M – 1×10 -12 M), a positive control (β-naphthoflavone) and solvent/negative control (1% DMSO) on each plate.…”

“…While relatively few studies (Isidori et al, 2003; Cupr et al, 2006; Slapsyte et al, 2006; Bonetta et al, 2009; Kennedy et al, 2009) have combined passive air sampling with effect based techniques, these samplers potentially provide a more convenient and cost effective means of monitoring the potential for biological effects resulting from exposure to complex mixtures in a range of scenarios. Since the compounds which will be sampled by these PUF samplers are those present predominantly in the vapour phase and in respirable particle size ranges (Chaemfa et al, 2009a), it is likely that effect based estimates derived from these samples will be particularly relevant from an inhalation toxicology perspective.…”

Assessment of estrogenic activity in PM10 air samples with the ERE-CALUX bioassay: Method optimization and implementation at an urban location in Flanders (Belgium)

“…This apparent recovery is higher than in this study, where median sample responses of 3.5 m 3 (for EC20) and 8.3 m 3 (for EC50) were found, suggesting that the extracts from the Canadian study were less potent compared to the ones in this study. Finally, an Australian study did not observe any significant estrogenic activity in outdoor air, but high potencies (in the range of several pg E2-Eq m À3 ) were measured in indoor office air and suburban homes (Kennedy et al, 2009). This suggests that although estrogenic activity was measured in more than 70% of the samples in this study, the BEQs were generally low compared to those from other studies reporting on indoor environments and outdoor air samples from smog episodes.…”