Spatial Distribution and Air–Water Exchange of Organic Flame Retardants in the Lower Great Lakes

Abstract

Organic flame retardants (OFRs) such as polybrominated diphenyl ethers (PBDEs) and novel halogenated flame retardants (NHFRs) are ubiquitous, persistent, and bioaccumulative contaminants that have been used in consumer goods to slow combustion. In this study, polyethylene passive samplers (PEs) were deployed throughout the lower Great Lakes (Lake Erie and Lake Ontario) to measure OFRs in air and water, calculate air-water exchange fluxes, and investigate spatial trends. Dissolved Σ12BDE was greatest in Lake Ontario near Toronto (18 pg/L), whereas gaseous Σ12BDE was greatest on the southern shoreline of Lake Erie (11 pg/m(3)). NHFRs were generally below detection limits. Air-water exchange was dominated by absorption of BDEs 47 and 99, ranging from -964 pg/m(2)/day to -30 pg/m(2)/day. Σ12BDE in air and water was significantly correlated with surrounding population density, suggesting that phased-out PBDEs continued to be emitted from population centers along the Great Lakes shoreline in 2012. Correlation with dissolved Σ12BDE was strongest when considering population within 25 km while correlation with gaseous Σ12BDE was strongest when using population within 3 km to the south of each site. Bayesian kriging was used to predict dissolved Σ12BDE over the lakes, illustrating the utility of relatively highly spatially resolved measurements in identifying potential hot spots for future study.

Field‐testing polyethylene passive samplers for the detection of neutral polyfluorinated alkyl substances in air and water

“…Three deuterated polycyclic aromatic hydrocarbons (PAHs; fluorene-d 10 , pyrene-d 10 , and benzo[a] pyrene-d 12 ) were used as PRCs; average PRC losses were 97% for fluorene-d 10 , 61% for pyrene-d 10 , and 2% for benzo[a]pyrened 12 . Sampling rates (R s ) were calculated as detailed in previous studies (McDonough et al 2016a(McDonough et al , 2016b. In the WWTP deployments performed here, R s averaged 28.1 AE 4.4 L/d.…”

Assessing soil-air partitioning of PAHs and PCBs with a new fugacity passive sampler

“…The unitless fugacity ratio ( f ratio ) indicates the net direction of exchange of a compound between the air and soil surface (Cabrerizo et al, 2009; Degrendele et al, 2016; Harner et al, 2001; McDonough et al, 2016; Wang et al, 2014; Wang et al, 2015): $$f_{\mathrm{italicratio}}=\frac{f_{\mathit{soil}\mathit{air}}}{f_{\mathrm{italicair}}}$$ where f ratio > 1 indicates volatilization out of the soil and f ratio < 1 indicates deposition.…”

“…Compared to active sampling methods, passive samplers are deployed for weeks at a time, require no electricity, and yield time-weighted averages (Zhang et al, 2011). Previously, passive samplers have been employed to measure in situ flux of hydrophobic organic contaminants between environmental compartments such as air and water (McDonough et al, 2016; Tidwell et al, 2016) and water and sediment porewater (Fernandez et al, 2014; Liu et al, 2013a). The few passive sampling studies that have measured soil air or soil-air partitioning in situ profiled concentration gradients using polyurethane foam passive samplers near the soil surface (Wang et al, 2017; Zhang et al, 2011).…”

Aryl hydrocarbon receptor‐mediated activity of gas‐phase ambient air derived from passive sampling and an in vitro bioassay

“…This approach for estimation of percentage of equilibration from PRC loss data has been described in detail in previous work (McDonough et al 2016). From the PRC loss data, the best-fit value for the thickness of the diffusive boundary layer (DBL) at the air-polyethylene passive sampler interface was determined.…”