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Gielen G.J.H.P.,Scion Research | van Schaik A.P.,Institute of Environmental Science and Research Ltd. | Northcott G.,Northcott Research Consultants Ltd. | Horswell J.,Institute of Environmental Science and Research Ltd.
Journal of Soils and Sediments | Year: 2016

Purpose: Sewage sludge and biosolid application to land is a common approach to fertilise soils, but sewage-derived contaminants like the antimicrobial agent triclosan, and heavy metals zinc and copper, are known to affect soil microbial communities. In this study, the tolerance to triclosan was examined for soil microbial communities chronically pre-exposed to one of two heavy metals (Cu or Zn) and the antimicrobial triclosan. This was investigated in two different soil types. Materials and methods: The impacts of chronic exposure of copper, zinc and triclosan as individual compounds or in mixtures on soil microbial communities were assessed in soils collected from two sites. The first was a Horotiu sandy loam with ample carbon and nitrogen levels and the second was a Templeton silt loam with very low carbon and nitrogen levels. The end points used to characterise the response of the soil microbial community were biomass, metabolic activity and pollution-induced community tolerance (PICT) to triclosan (using Biolog EcoPlates). In addition, metabolic activities for individual substrates were examined and those that significantly changed with the applied treatments were identified. Results and discussion: Exposure to mixtures of both triclosan and copper in the Horotiu sandy loam reduced microbial biomass, increased metabolic activity and reduced microbial tolerance to triclosan. The decrease in soil microbial tolerance correlated with an increased metabolic activity for N-acetyl-d-glucosamine providing a potential link between triclosan exposure and nitrogen mineralisation. Exposure to both triclosan and high zinc levels decreased microbial biomass in the Horotiu sandy loam but did not have an effect on microbial tolerance to triclosan. In the finer-textured and less fertile Templeton soil, microbial tolerance to triclosan and the microbial biomass were not impacted by copper/triclosan or zinc/triclosan mixtures. Conclusions: Mixture effects could become a cause for concern when soil microbial communities are exposed to triclosan in fertile soils with copper concentrations in excess of 50 mg kg−1 and could be especially important in the more coarsely textured soils. Current regulations for soil contaminants only consider the risk and effects of single contaminants. Greater protection of soil resources could result from considering mixture effects and soil types. © 2016 Springer-Verlag Berlin Heidelberg


Stringer T.J.,University of Canterbury | Stringer T.J.,Landcare Research | Glover C.N.,University of Canterbury | Keesing V.,Boffa Miskell Ltd | And 4 more authors.
Ecotoxicology and Environmental Safety | Year: 2014

Reliable environmentally realistic bioassay methodologies are increasingly needed to assess the effects of environmental pollution. This study describes two estuarine sediment bioassays, one acute (96h) and one chronic (14d), with the New Zealand harpacticoid copepod Quinquelaophonte sp. utilising behavioural and reproductive endpoints. Spiked sediments were used to expose Quinquelaophonte sp. to three reference compounds representing important categories of estuarine chemical stressors: zinc (a metal), atrazine (a pesticide), and phenanthrene (a polycyclic aromatic hydrocarbon). Acute-to-chronic ratios (ACR) were used to further characterise species responses. Acute sediment (sandy and low total organic content) 96h EC50 values for the sublethal inhibition of mobility for zinc, atrazine and phenanthrene were 137, 5.4, and 2.6μg/g, respectively. The chronic EC50 values for inhibition of reproduction (total offspring) were 54.5, 0.0083, and 0.067μg/g for zinc, atrazine, and phenanthrene, respectively. For phenanthrene, a potentially novel mode of action was identified on reproduction. Quinquelaophonte sp. was found to be more sensitive than several other estuarine species indicating choice of test organism is important to characterising the effects of environmentally relevant levels of contamination. The bioassay sediment results demonstrate the sensitivity and suitability of Quinquelaophonte sp. as a tool for the assessment use of estuarine health. © 2013 Elsevier Inc.


Horswell J.,Institute of Environmental Science and Research ESR Ltd | Prosser J.A.,Institute of Environmental Science and Research ESR Ltd | Siggins A.,Institute of Environmental Science and Research ESR Ltd | van Schaik A.,Institute of Environmental Science and Research ESR Ltd | And 4 more authors.
Soil Biology and Biochemistry | Year: 2014

Little is known about the environmental fate and effect of low levels of co-contaminants that are commonly present in wastes such as biosolids. Lysimeters were established using soils contaminated with Cu or Zn and augmented with triclosan. Triclosan degraded rapidly in the soils, with methyl-triclosan being the major degradation product. However, as metal concentration increased, transformation and biodegradation of triclosan decreased. For some soil health indicators (e.g. sulphatase enzyme), results suggested that general toxicity was increased when metals and triclosan were both present. These preliminary results suggest that co-contaminants can result in a combined effect that is potentially greater than the sum of the individual effects, with additional impacts on the rate and extent of contaminant degradation. © 2014 Elsevier Ltd.


Hamilton L.A.,University of Technology, Sydney | Tremblay L.A.,Cawthron Institute | Tremblay L.A.,University of Auckland | Northcott G.L.,Northcott Research Consultants Ltd | And 2 more authors.
Science of the Total Environment | Year: 2016

The impact of changes in influent load on the removal of endocrine disrupting chemicals (EDCs) by sewage treatment has not been fully characterised. This study assessed the efficacy of an advanced tertiary sewage treatment plant (STP) to remove EDCs during normal and peak flow events of sewage influent using trace chemical analysis of selected EDCs and four estrogenic in vitro bioassays. During the summer holiday season, influent volume increased by 68%, nutrient concentrations by at least 26% and hydraulic retention time was reduced by 40% compared with base flow conditions. Despite these pressures on the treatment system the concentrations and mass loading of estrone, 17β-estradiol, estriol, Bisphenol A, 4-t-octylphenol and technical nonylphenol were not significantly higher (p > 0.05) during the peak flow conditions compared with base flow conditions. Chemical analysis and in vitro bioassays showed that the efficacy of the STP in removing EDCs was not affected by the different loadings between baseline and peak flow regimes. This study demonstrates that large flow variations within the design capacity of advanced multi-stage STPs should not reduce the removal efficacy of EDCs. © 2016 Elsevier B.V.


PubMed | Northcott Research Consultants Ltd, University of Heidelberg and Cawthron Institute
Type: | Journal: Ecotoxicology (London, England) | Year: 2017

Sediments represent a major sink for contaminants resulting from industrial and agricultural activities-especially lipophilic substances. This study exclusively used in vitro methodologies to characterize specific toxicity effects of contaminants in sediment extracts from two urban New Zealand estuaries. Sediment extracts were prepared and tested for a range of biological endpoints. The micronucleus and comet assays in V79 cells were used to assess genotoxicity. Induction of 7-ethoxyresorufin-O-deethylase in piscine RTL-W1 cells was determined to estimate dioxin-like toxicity. Cytotoxic potentials were analyzed by neutral red uptake and MTT reduction. There was evidence of strong dioxin-like toxicity and moderate cytotoxicity. Genotoxicity was distinct in the micronucleus assay, but low in the comet assay. The results indicate the presence of chemicals in the sediments with the potential to pose a risk through multiple mechanisms of toxicity, the identities and amounts of which will be disclosed in a parallel study alongside with in vivo toxicity data.


PubMed | Northcott Research Consultants Ltd, University of Technology, Sydney, Bay Center and Cawthron Institute
Type: | Journal: The Science of the total environment | Year: 2016

The impact of changes in influent load on the removal of endocrine disrupting chemicals (EDCs) by sewage treatment has not been fully characterised. This study assessed the efficacy of an advanced tertiary sewage treatment plant (STP) to remove EDCs during normal and peak flow events of sewage influent using trace chemical analysis of selected EDCs and four estrogenic in vitro bioassays. During the summer holiday season, influent volume increased by 68%, nutrient concentrations by at least 26% and hydraulic retention time was reduced by 40% compared with base flow conditions. Despite these pressures on the treatment system the concentrations and mass loading of estrone, 17-estradiol, estriol, Bisphenol A, 4-t-octylphenol and technical nonylphenol were not significantly higher (p>0.05) during the peak flow conditions compared with base flow conditions. Chemical analysis and in vitro bioassays showed that the efficacy of the STP in removing EDCs was not affected by the different loadings between baseline and peak flow regimes. This study demonstrates that large flow variations within the design capacity of advanced multi-stage STPs should not reduce the removal efficacy of EDCs.


PubMed | Australian Institute of Marine Science, Northcott Research Consultants Ltd, Charles Darwin University and CSIRO
Type: | Journal: The Science of the total environment | Year: 2015

The detection of microcontaminants in aquatic environments raises concerns about their potential to exert ecotoxicological effects and impact human health. In contrast to freshwater habitats, little information is available on environmental concentrations in urban estuarine and marine environments. This study investigated an extensive range of organic and inorganic microcontaminants in the Darwin Harbour catchment, a tropical estuary in northern Australia undergoing rapid urbanisation and industrial development. We sampled wastewater effluent and surface water from seven sites in Darwin Harbour for pharmaceuticals and personal care products, alkylphenols, hormones, pesticides, herbicides and metals. In vitro bioassays were used to estimate the (anti)estrogenic and (anti)androgenic activities of samples. Seventy-nine of 229 organic microcontaminants analysed were detected at concentrations ranging from 0.01 to 20 g/L, with acesulfame, paracetamol, cholesterol, caffeine, DEET and iopromide detected at the highest concentrations in wastewater effluent (20 g/L, 17 g/L, 11 g/L, 11 g/L, 10 g/L and 7.6 g/L, respectively). Levels of estrogenic activity ranged from estradiol equivalency quotients (EEQs) of <0.10 to 6.290.16 ng/L while levels of androgenic activity ranged from dihydrotestosterone equivalency quotients (DHTEQs) of <3.50 to 138.233.71 ng/L. Environmental concentrations of organic microcontaminants were comparable to ranges reported from aquatic environments worldwide with sewage effluent discharges representing the dominant source of entry into Darwin Harbour. The measured concentration range of DEET was higher than ranges reported in previous studies.


Gaskin R.E.,Plant Protection ChemistryNZ | Manktelow D.W.L.,Manktelow and Associates Ltd. | Northcott G.L.,Northcott Research Consultants Ltd.
New Zealand Plant Protection | Year: 2014

Autumn leaf scars are an important pathogen infection site for European canker on apples. Trials were undertaken to evaluate the effects of adjuvants on spray coverage of new leaf scars, and determine if adjuvants could (1) impart any significant rainfastness to protectant captan sprays and (2) provide any redistribution of captan during a rain event post-leaf drop. Retention on fresh leaf scars was increased with the use of organosilicone-latex sticker adjuvants only. Rain had little effect on spray residues but these adjuvants could improve rainfastness of captan due to their effects on spray retention. Retention on stem wood and around leaf nodes was increased by up to seven-fold with the use of superspreader-type adjuvants, due to redistribution of spray runoff from leaves. High initial deposits resulted in post-rain residues on leaf scars three-fold higher than a captan spray alone. Redistribution of captan onto exposed leaf scars in rain appears likely with these adjuvants. © 2014 New Zealand Plant Protection Society (Inc.).


Emnet P.,University of Canterbury | Gaw S.,University of Canterbury | Northcott G.,Northcott Research Consultants Ltd | Storey B.,University of Canterbury | Graham L.,University of Canterbury
Environmental Research | Year: 2015

Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aquatic environment. Despite intense research on the fate and effects of PPCPs in temperate climates, there is a paucity of data on their presence in polar environments. This study reports the presence of selected PPCPs in sewage effluents from two Antarctic research stations, the adjacent coastal seawater, sea ice, and biota. Sewage effluents contained bisphenol-A, ethinylestradiol, estrone, methyl triclosan, octylphenol, triclosan, and three UV-filters. The maximum sewage effluent concentrations of 4-methyl-benzylidene camphor, benzophenone-1, estrone, ethinylestradiol, and octylphenol exceeded concentrations previously reported. Coastal seawaters contained bisphenol-A, octylphenol, triclosan, three paraben preservatives, and four UV-filters. The sea ice contained a similar range and concentration of PPCPs as the seawater. Benzophenone-3 (preferential accumulation in clams), estradiol, ethinylestradiol, methyl paraben (preferential accumulation in fish, with concentrations correlating negatively with fillet size), octylphenol, and propyl paraben were detected in biota samples. PPCPs were detected in seawater and biota at distances up to 25. km from the research stations WWTP discharges. Sewage effluent discharges and disposal of raw human waste through sea ice cracks have been identified as sources of PPCPs to Antarctic coastal environments. © 2014 Elsevier Inc.


PubMed | Northcott Research Consultants Ltd and University of Canterbury
Type: | Journal: Environmental research | Year: 2014

Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aquatic environment. Despite intense research on the fate and effects of PPCPs in temperate climates, there is a paucity of data on their presence in polar environments. This study reports the presence of selected PPCPs in sewage effluents from two Antarctic research stations, the adjacent coastal seawater, sea ice, and biota. Sewage effluents contained bisphenol-A, ethinylestradiol, estrone, methyl triclosan, octylphenol, triclosan, and three UV-filters. The maximum sewage effluent concentrations of 4-methyl-benzylidene camphor, benzophenone-1, estrone, ethinylestradiol, and octylphenol exceeded concentrations previously reported. Coastal seawaters contained bisphenol-A, octylphenol, triclosan, three paraben preservatives, and four UV-filters. The sea ice contained a similar range and concentration of PPCPs as the seawater. Benzophenone-3 (preferential accumulation in clams), estradiol, ethinylestradiol, methyl paraben (preferential accumulation in fish, with concentrations correlating negatively with fillet size), octylphenol, and propyl paraben were detected in biota samples. PPCPs were detected in seawater and biota at distances up to 25 km from the research stations WWTP discharges. Sewage effluent discharges and disposal of raw human waste through sea ice cracks have been identified as sources of PPCPs to Antarctic coastal environments.

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