Gavin Rose

Effects of pesticides monitored with three sampling methods in 24 sites on macroinvertebrates and microorganisms.

Grab water samples, sediment samples, and 2,2,4-trimethylpentane passive samplers (TRIMPS) were used to determine the exposure to 97 pesticides in 24 southeast Australian stream sites over 5 months. Macroinvertebrate communities and selected microorganisms (bacteria, flagellates, ciliates, amoebas, nematodes, and gastrotrichs) were sampled to detect relationships with pesticide toxicity. Sediment samples had the highest estimated toxicities in terms of toxic units (TU) for Daphnia magna (TUDM) and for Selenastrum capricornutum (TUSC). The pesticide-selective SPEARpesticides and the general SIGNAL index for macroinvertebrates exhibited negative linear relationships (r(2) = 0.67 and 0.36, respectively) with pesticide contamination in terms of log maximum TUDM (log mTUDM), suggesting macroinvertebrate community change due to pesticide exposure. Pesticide contamination was the only measured variable explaining variation in ecological quality. Variation in the densities of several microbial groups was best explained by environmental variables other than log TUs. The log mTUDM values derived from sediment concentrations were most important to establish a link with effects on macroinvertebrates, whereas log mTUDM of grab water samples had only minor contribution. Current-use insecticides and fungicides can affect macroinvertebrate communities and monitoring of sediment and continuous water sampling is needed to detect these effects.

Ecological evidence links adverse biological effects to pesticide and metal contamination in an urban Australian watershed

Summary: Aquatic ecosystems near urban areas are often ecologically impaired, but causative factors are rarely identified. Effects may be revealed by considering multiple lines of evidence at different levels of biological organization. Biological impairment is evident in the urban section of the Upper Dandenong Creek Catchment (Victoria, Australia). We assessed whether episodic sewage spills or other pollutants were the cause of poor ecological condition in the stream. The evidence evaluated included chemical and invertebrate assessments, caging studies of mudsnails Potamopyrgus antipodarum, antioxidant biomarkers and endocrine disruption-related endpoints in fish (Carassius auratus and Gambusia holbrooki) and toxicological studies with chironomids (Chironomus tepperi). A combination of metals and pesticides is likely to be affecting the aquatic fauna across all biological levels, with macroinvertebrate communities, P. antipodarum and C. tepperi populations and C. auratus individuals all ecologically impaired. Adverse alterations to aquatic fauna were consistently seen in Bungalook Creek and persisted downstream of this confluence into Dandenong Creek. In addition, chemical assessments and toxicity identification evaluation (TIEs) resulted in several point sources of both metals and pesticides being identified as origins of impairment. This contrasted with an expectation that adverse effects were likely to be associated with sewer-related pollution. As a consequence, target areas and specific pollutants were identified for remediation instead of an expensive sewer upgrade. Synthesis and applications. The results demonstrate that it is important to investigate biological effects in different taxa, in both the laboratory and field, to understand which stressors are causing adverse effects on faunal assemblages. When adverse effects are seen across multiple levels of biological organization and caused by the same pollutant from an identifiable source, there is a clear

Mixed-mode solid-phase extraction coupled with liquid chromatography tandem mass spectrometry to determine phenoxy acid, sulfonylurea, triazine and other selected herbicides at nanogram per litre levels in environmental waters

The method presented uses a mixed-mode anion exchange SPE and liquid chromatography tandem mass spectrometry to analyze 5 sulfonylurea, 8 phenoxy acid, 12 triazine and 6 other herbicides in environmental waters. The mixed-mode SPE cartridge is able to retain a wide range of herbicides with acidic-neutral-basic characteristics, particularly the highly polar and acidic compounds clopyralid, dicamba and picloram. The neutral and basic herbicides can be effectively eluted with methanol, after which the acidic herbicides can be eluted using acidified methanol. The method has achieved an LOD of 0.7-3ng/L for the sulfonylureas, 4-12ng/L for the phenoxy acids and 0.4-30ng/L for the triazine and additional herbicides, with recoveries in the range 76-107%, 73-126%, and 65-104%, respectively. The precision of the method, calculated as relative standard deviation (RSD), was below 10% for both sulfonylurea and phenoxy acid herbicides, and less than 20% for the remaining herbicides. The developed method was used to determine the concentration of target herbicides in a range of environmental waters, and many of the target herbicides were detected at ng/L level.

Herbicides and trace metals in urban waters in Melbourne, Australia (2011-12): concentrations and potential impact

Urban stormwater samples were collected from five aquatic systems in Melbourne, Australia, on six occasions between October 2011 and March 2012 and tested for 30 herbicides and 14 trace metals. Nineteen different herbicides were observed in one or more water samples from the five sites; chemicals observed at more than 40% of sites were simazine (100%), MCPA (83%), diuron (63%) and atrazine (53%). Using the toxicity unit (TU) concept to assess potential risk to aquatic ecosystems, none of the detected herbicides were considered to pose an individual, group or collective short-term risk to fish or zooplankton in the waters studied. However, 13 herbicides had TU values suggesting they might have posed an individual risk to primary producers at the time of sampling. Water quality guideline levels were exceeded on many occasions for Cd, Cu, Cr, Pb and Zn. Similarly, RQmed and RQmax exceeded 1 for Cd, Cr, Cu, Mn, Ni, Pb, V and Zn. Almost all the metals screened exceeded a log10TU of −3 for every trophic level, suggesting that there may have been some impact on aquatic organisms in the studied waterbodies. Our data indicate that Melbourne’s urban aquatic environments may be being impacted by approved domestic, industrial and sporting application of herbicides and that stormwater quality needs to be carefully assessed prior to reuse. Further research is required to understand the performance of different urban stormwater wetland designs in removing pesticides and trace metals. Applying the precautionary principle to herbicide regulation is important to ensure there is more research and assessment of the long-term ‘performance’ standard of all herbicides and throughout their ‘life cycle’. Implementing such an approach will also ensure government, regulators, decision makers, researchers, policy makers and industry have the best possible information available to improve the management of chemicals, from manufacture to use.

Pesticide and trace metals in surface waters and sediments of rivers entering the Corner Inlet Marine National Park, Victoria, Australia

Water and sediment samples were collected from up to 17 sites in waterways entering the Corner Inlet Marine National Park monthly between November 2009 and April 2010, with the Chemcatcher passive sampler system deployed at these sites in November 2009 and March 2010. Trace metal concentrations were low, with none occurring at concentrations with the potential for adverse ecological effects. The agrochemical residues data showed the presence of a small number of pesticides at very low concentration (ng/L) in the surface waters of streams entering the Corner Inlet, and as widespread, but still limited contamination of sediments. Concentrations of pesticides detected were relatively low and several orders of magnitude below reported ecotoxicological effect and hazardous concentration values. The low levels of pesticides detected in this study indicate that agricultural industries were responsible agrochemical users. This research project is a rarity in aligning both agrochemical usage data obtained from chemical resellers in the target catchment with residue analysis of environmental samples. Based on frequency of detection and concentrations, prometryn is the priority chemical of concern for both the water and sediments studied, but this chemical was not listed in reseller data. Consequently, the risks may be greater than the field data would suggest, and priorities for monitoring different since some commonly used herbicides (such as glyphosate, phenoxy acid herbicides, and sulfonyl urea herbicides) were not screened. Therefore, researchers, academia, industry, and government need to identify ways to achieve a more coordinated land use approach for obtaining information on the use of chemicals in a catchment, their presence in waterways, and the longer term performance of chemicals, particularly where they are used multiple times in a year.

Analysis of free and bound phenolics in wine and grapes by GC–MS after automated SPE

The results of validation of a method for the analysis of free and bound phenolics in wine and grapes are presented. Wine and grape extracts are fractionated by automated solid-phase extraction on Bond Elut PPL cartridges to give free and bound phenolic fractions. Bound fractions are subjected to acid hydrolysis, and the phenolics released are recovered by solid-phase extraction on Bond Elut PPL cartridges. The fractions are further purified by automated solid-phase extraction on Bond Elut silica cartridges. After derivatisation to form trimethylsilyl ethers, the phenolics are determined by gas chromatography–mass spectrometry with selected ion monitoring. The method is suitable for robust, high-throughput monitoring of the concentrations of phenolics that can affect the palatability of wine.

Potentially Toxic Concentrations of Synthetic Pyrethroids Associated with Low Density Residential Land Use

Trace organic compounds associated with human activity are now ubiquitous in the environment. As the population becomes more urbanised and the use of pesticides and person care products continues to increase, urban waterways are likely to receive higher loads of trace organic contaminants with unknown ecological consequences. To establish the extent of trace organic contamination in urban runoff, concentrations of emerging chemicals of concern were determined in sediments from 99 urban wetlands in and around Melbourne, Australia between February and April, 2015. As a preliminary estimation of potential risks to aquatic biota, we compared measured concentrations with thresholds for acute and chronic toxicity, and modelled toxic units as a function of demographic and land use trends. The synthetic pyrethroid insecticide bifenthrin was common and widespread, and frequently occurred at concentrations likely to cause toxicity to aquatic life. Personal care products DEET and triclosan were common and widely distributed, while the herbicides diuron and prometryn, and the fungicides pyrimethanil and trifloxystrobin occurred less frequently. Toxic unit modelling using random forests found complex and unexpected associations between urban land uses and trace organic concentrations. Synthetic pyrethroid insecticides were identified as emerging compounds of concern, particularly bifenthrin. In contrast with previous surveys, the highest bifenthrin concentrations were associated with lower housing and population density, implicating low-density residential land use in bifenthrin contamination. We discuss the implications for pesticide regulation and urban wetland management in a global context.