Using silicone passive samplers to detect polycyclic aromatic hydrocarbons from wildfires in streams and potential acute effects for invertebrate communities

Improvements in pollutant monitoring: Optimizing silicone for co-deployment with polyethylene passive sampling devices

“…Although polymer cleaning results are rarely reported, this methodology compares well with others that rely on solvent exchanges (Booij et al, 2002; Rusina et al, 2007; Schafer et al, 2010), and it is faster (≤ 48h) than soxhlet extraction methods (90h) (Yates et al, 2007; Monteyne et al, 2013). Moreover, solvents could be effectively recycled (both hexane/ethyl acetate and methanol/ethyl acetate mixtures) between batches of silicone (SI-Figure 1B).…”

“…In addition, to exploit inherent differences in each polymer, ethyl acetate was used as the primary solvent for silicone, while the more non-polar hexane was used for LDPE cleaning as previously described (Anderson et al, 2008). Pre-cleaning experiments for silicones were adapted from several studies (Booij et al, 2002; Rusina et al, 2007; Yates et al, 2007; Allan et al, 2009; Schafer et al, 2010). Ultimately, sufficient reduction of siloxane background was only achieved with a combination of three extraction periods of 1:1, hexane:ethyl acetate, followed by two more periods of 1:1 methanol:ethyl acetate.…”

Quantity, composition and water contamination potential of ash produced under different wildfire severities

“…For example polycyclic aromatic hydrocarbons (PAHs), which are generated during wildfires (Vergnoux et al, 2011), are of great concern for water supply managers due to their carcinogenic potential. However, a previous study identifying potential acute effects from PAHs in surface waters after severe wildfires in Australian eucalyptus forests (2009 'Black Saturday Fires', Victoria) suggested that they are unlikely to be a common main cause for fire-related ecological impacts in this region (Schäfer et al, 2010).…”

Toxicity assessment of aqueous extracts of ash from forest fires

“…Studies in different geographical regions, including Portugal (e.g., Ferreira et al, 2008;Malvar et al, 2011;Prats et al, 2012), have shown strong to extreme responses in runoff generation and associated soil losses following wildfires. Heavy rainfall has been identified as a triggering factor for these post-fire effects, generating extensive transport of ash and soil into aquatic systems (e.g., Cerdà and Doerr, 2008;Malvar et al, 2013;Pereira et al, 2013;Prats et al, 2014;Schäfer et al, 2010). Also the ash itself -amount, type and thicknesscan play an important role in the post-fire hydrologic response that is worth mentioning: ash may increase or reduce the post-fire runoff by sealing the soil pores or by increasing the storage and infiltration of water, respectively (e.g., León et al, 2013;Woods and Balfour, 2010).…”

“…However, contamination by pyrolytic substances has increasingly received research attention, in particular polycyclic aromatic hydrocarbons (PAHs) and chemical elements (Campos et al, 2012;Ignatavičius et al, 2006;Olivella et al, 2006;Schäfer et al, 2010;Smith et al, 2011;Vila-Escalé et al, 2007). Both PAHs and certain chemical elements like metals are contaminants of major biological concern, due to their high toxicity, environmental persistence and tendency to bioaccumulate (e.g., Manoli and Samara, 1999;Vila-Escalé et al, 2007).…”