Spatial variation of short- and medium-chain chlorinated paraffins in ambient air across Australia.

Atmospheric levels of chlorinated paraffins (CPs) at five remote, six rural and four urban sites in Australia were measured using XAD-2 passive air samplers (XAD-PAS). While long-chain CP (LCCP, C>17) levels were below method detection limits (MDLs), short-chain CPs (SCCPs, C10-13) and, for the first time, medium-chain CPs (MCCPs, C14-17) and CPs with a carbon chain length of nine (CP-C9) were found at many sites (88%, 81% and 88%, respectively) across the Australian continent, representing a range of environmental conditions. Applying preliminary sampling rates of the XAD-PAS for CPs, gaseous CP levels in Australian air were

Spatial distribution of selected persistent organic pollutants (POPs) in Australia's atmosphere.

A nation-wide passive air sampling campaign recorded concentrations of persistent organic pollutants in Australia's atmosphere in 2012. XAD-based passive air samplers were deployed for one year at 15 sampling sites located in remote/background, agricultural and semi-urban and urban areas across the continent. Concentrations of 47 polychlorinated biphenyls ranged from 0.73 to 72 pg m(-3) (median of 8.9 pg m(-3)) and were consistently higher at urban sites. The toxic equivalent concentration for the sum of 12 dioxin-like PCBs was low, ranging from below detection limits to 0.24 fg m(-3) (median of 0.0086 fg m(-3)). Overall, the levels of polychlorinated biphenyls in Australia were among the lowest reported globally to date. Among the organochlorine pesticides, hexachlorobenzene had the highest (median of 41 pg m(-3)) and most uniform concentration (with a ratio between highest and lowest value ∼5). Bushfires may be responsible for atmospheric hexachlorobenzene levels in Australia that exceeded Southern Hemispheric baseline levels by a factor of ∼4. Organochlorine pesticide concentrations generally increased from remote/background and agricultural sites to urban sites, except for high concentrations of α-endosulfan and DDTs at specific agricultural sites. Concentrations of heptachlor (0.47-210 pg m(-3)), dieldrin (ND-160 pg m(-3)) and trans- and cis-chlordanes (0.83-180 pg m(-3), sum of) in Australian air were among the highest reported globally to date, whereas those of DDT and its metabolites (ND-160 pg m(-3), sum of), α-, ß-, γ- and δ-hexachlorocyclohexane (ND-6.7 pg m(-3), sum of) and α-endosulfan (ND-27 pg m(-3)) were among the lowest.

The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides.

The 2010-2011 wet season was one of extreme weather for the State of Queensland, Australia. Major rivers adjacent to the Great Barrier Reef (GBR) were discharging at rates 1.5 to >3 times higher than their long term median. Exposure to photosystem II herbicides has been routinely monitored over a period of up to 5 years at 12 inshore GBR sites. The influence of this wet season on exposure to photosystem II herbicides was examined in the context of this long-term monitoring record and during flood plume events in specific regions. Median exposures expressed as diuron equivalent concentration were an average factor of 2.3 times higher but mostly not significantly different (p<0.05) to the median for the long-term monitoring record. The herbicides metolachlor and tebuthiuron were frequently detected in flood plume waters at concentrations that reached or exceeded relevant water quality guidelines (by up to 4.5 times).

Long term monitoring of photosystem II herbicides--correlation with remotely sensed freshwater extent to monitor changes in the quality of water entering the Great Barrier Reef, Australia.

Photosystem II (PSII) herbicides are used in large quantities on agricultural lands adjoining the Great Barrier Reef (GBR). Routine monitoring at 14 sites in inshore waters of the GBR using passive sampling techniques detected diuron (32-94% of sampling periods) at maximum concentrations of 1.7-430ng L(-1) in the relatively pristine Cape York Region to the Mackay Whitsunday Region, respectively. A PSII herbicide equivalent (PSII-HEq) index developed as an indicator for reporting was dominated by diuron (average contribution 89%) and typically increased during the wet season. The maximum PSII-HEq indicates the potential for photosynthetic inhibition of diatoms, seagrass and coral-symbionts. PSII herbicides were significantly positively correlated with remotely sensed coloured dissolved organic matter, a proxy for freshwater extent. Combining these methods provides for the first time the potential to cost-effectively monitor improvements in water quality entering the GBR with respect to exposure to PSII herbicides.