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1.
J Photochem Photobiol B ; 149: 280-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26117416

ABSTRACT

The photoprotective role of mycosporine-like amino acids (MAA) against the generation of DNA cyclobutane pyrimidine dimers (CPD) was studied in the sessile intertidal anemone Actinia tenebrosa and the mobile intertidal gastropod Diloma aethiops through 27months at a mid-latitude New Zealand location. MAA were sequestered by A. tenebrosa and D. aethiops from their diet, although maximum total MAA levels in both species were not correlated with seasonal variation in maximum ambient UV-B levels recorded at the collection site. Temporal changes in total MAA in A. tenebrosa showed a six months lag-time in their concentration regarding to the environmental UV-B levels. This lag period corresponded to an observed increase in CPD production from spring to summer; suggesting that MAA do not completely protect the anemone from UV-B during summer. For D. aethiops, total MAA concentrations did not change significantly during the study, although qualitative changes in MAA were apparent. A month lag-time in MAA concentration in D. aethiops and possibly the physical barrier that the shell confers to the animal, can explain reduced CPD levels in comparative terms with A. tenebrosa. Although MAA are used by invertebrates for photoprotection, contrasting mobility characteristics and the presence of physical adaptations can confer them important protection levels during temporal changes of UV-B at mid-latitude places of the Southern Hemisphere.


Subject(s)
Amino Acids/metabolism , DNA Damage , Gastropoda/genetics , Gastropoda/radiation effects , Sea Anemones/genetics , Sea Anemones/radiation effects , Ultraviolet Rays/adverse effects , Adaptation, Physiological , Animals , Gastropoda/metabolism , Gastropoda/physiology , Movement/radiation effects , Pyrimidine Dimers/metabolism , Sea Anemones/metabolism , Sea Anemones/physiology , Time Factors
2.
Forensic Sci Int ; 251: 214-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25955952

ABSTRACT

The trace metal content of roots of samples of the American ginseng natural herbal plant species (Panax quinquefolius) was investigated as a means of differentiating between this species grown on Wisconsin and New Zealand farms, and from Canadian and Chinese sources. ICP-MS measurements were undertaken by ashing samples of the roots and then digestion with conc. HNO3 and H2O2. There was considerable variation in the concentrations of 28 detectable elements along the length of a root, between different roots, between different farms/sources and between different countries. Statistical processing of the log-transformed concentration data was undertaken using principal component analysis (PCA) and discriminant function analysis (DFA). Although PCA showed some differentiation between samples, a much clearer discrimination of the Panax quinquefolius species of ginseng from the four countries was observed using DFA. 88% of the variation between countries could be accounted for by only using discriminant function 1 while 80% of the remaining 12% of the variation between countries is accounted for by discriminant function 2. The Fisher Classification Functions classify 98% of the 87 samples to the correct country of origin with 97% of the cross-validated cases correctly classified. The predictive ability of this DFA model was further tested by constructing 100 discriminant models each using a random selection of the data for two thirds of the 87 sampled ginseng root tops, and then using the resulting classification functions to determine correctly the country of origin of the remaining third of the cases. The mean success rate of the 100 classifications was 92%. These results suggest that measurement and statistical analysis of just the trace metal content of the roots of Panax quinquefolius promises to be an excellent predictor of the country of origin of this ginseng species.


Subject(s)
Mass Spectrometry/methods , Metals/analysis , Panax/chemistry , Plant Roots/chemistry , Botany , Canada , China , Discriminant Analysis , Forensic Sciences , Geography , New Zealand , Principal Component Analysis , Wisconsin
3.
Photochem Photobiol ; 90(6): 1314-23, 2014.
Article in English | MEDLINE | ID: mdl-25041232

ABSTRACT

To assess the relative importance of long- and short-term cellular defense mechanisms in seasonally UV-R-acclimated Actinia tenebrosa (Anthozoa, Actiniidae), individuals were exposed to summer doses of PAR, UV-A, UV-B and enhanced UV-B (20%) for a period of 4 days. Mycosporine-like amino acids (MAAs) and cyclobutane pyrimidine dimer (CPD) concentrations were quantified, while oxidative damage to lipids and proteins, and the activities or levels of the antioxidant enzymes SOD, CAT, GR, GPOX and total glutathione were determined. Our results show that summer UV-R-acclimated individuals had a higher UV-R tolerance, with no significant increases in CPDs levels, than winter-acclimated sea anemones possibly due to higher MAA concentrations. Summer-acclimated individuals showed increased lipid and protein oxidation and GPOX activity only when they were exposed to UV-B at 20% above ambient UV-R levels. In contrast, winter-acclimated sea anemones showed elevated levels of oxidative damage, GPOX and SOD activities after exposure to UV-A or UV-B at ambient and elevated levels. Thus, this study indicates that long-term UV-R acclimation mechanisms such as the accumulation of MAAs could be more important than short-term increases in antioxidant defenses with respect to reducing indirect UV-R damage in intertidal sea anemones.


Subject(s)
Adaptation, Physiological , Sea Anemones/physiology , Ultraviolet Rays , Amino Acids/metabolism , Animals , Antioxidants/metabolism , Oxidative Stress , Pyrimidine Dimers/metabolism , Sea Anemones/cytology , Sea Anemones/radiation effects
4.
J AOAC Int ; 97(2): 325-33, 2014.
Article in English | MEDLINE | ID: mdl-24830143

ABSTRACT

Two methods for the determination of tetrodotoxin (TTX) in marine biota have been developed and validated using ultra-performance LC coupled to triple quadrupole MS. The direct analysis of TTX is completed in one method, while the other method detects the dehydration product of TTX after reaction with base. The methods were validated in a single-laboratory trial and used to test Paphies australis (pipi) samples collected from Whangapoua, New Zealand during April 2011. Pa. australis is a commonly eaten species of bivalve that was found to contain TTX at levels up to 0.80 mg/kg in this study. The methods exhibited recoveries ranging from 94 to 120%, and the within laboratory reproducibility ranged from 6 to 27% for Pleurobranchaea maculata (grey-side gilled sea slug) and bivalve matrixes. Use of the method using a dehydration step showed no evidence of TTX analogs in any of the samples.


Subject(s)
Bivalvia/chemistry , Chromatography, Liquid/methods , Mass Spectrometry/methods , Tetrodotoxin/chemistry , Animals , Food Analysis , Molecular Structure , New Zealand , Reproducibility of Results
5.
J Hazard Mater ; 217-218: 382-90, 2012 May 30.
Article in English | MEDLINE | ID: mdl-22487138

ABSTRACT

Antidepressant pharmaceuticals have recently been detected at low concentrations in wastewater and surface water. This work reports studies of the direct and indirect photochemical fate and treatment by advanced oxidation of three antidepressant compounds (duloxetine, venlafaxine and bupropion) in solutions of humic acid in order to elucidate their behavior in the natural environment prior to reaching a water treatment facility and potentially entering a potable water supply. Humic acid solution was prepared by adding to distilled water a known amount of organic matter as a photosensitizer. All three antidepressants react very rapidly with hydroxyl radicals (·OH) and hydrated electrons (e(-)(aq)) with rate constants of ~10(8) to 10(10)M(-1)s(-1), but significantly slower with singlet oxygen ((1)ΔO(2)) (~10(3) to 10(5)M(-1)s(-1)). The steady-state concentrations of ·OH and (1)ΔO(2), in a sample of humic acid solution were measured and used with the second order rate constants to show that the hydroxyl radical was an order of magnitude more effective than the singlet oxygen in the solar-induced photochemical degradation of the antidepressants. Excited state dissolved organic matter also accounted for a substantial portion of degradation of duloxetine, decreasing its half-life by 27% under solar irradiation. Several reaction pathways and by-products arising from the photodegradation were identified using gamma-irradiation followed by LC-MS analysis.


Subject(s)
Antidepressive Agents/chemistry , Humic Substances , Photochemical Processes , Water Pollutants, Chemical/chemistry , Fresh Water , Oxidation-Reduction
6.
J Prim Health Care ; 3(3): 197-203, 2011 Sep 01.
Article in English | MEDLINE | ID: mdl-21892421

ABSTRACT

INTRODUCTION: One of the recommended methods for households to dispose of unused medications in many countries is to return them to community pharmacies. However, such a practice will only reduce the environmental levels of pharmaceuticals if the medications are also disposed of and destroyed properly by the pharmacies. AIM: This study reports the results of a questionnaire sent to New Zealand community pharmacists regarding disposal practices for unused or expired medications in their workplaces. METHODS: A pre-tested, self-administered questionnaire was sent to 500 randomly selected community pharmacies from all areas of New Zealand. The participants were asked how they disposed of a variety of medications. In addition, participants were also asked about whether they knew how unused medications were destroyed if their pharmacy used a third-party contractor or distributor to dispose of them. RESULTS: Of the 265 respondents, 80.4% and 61.1% respectively reported that solid and semi-solid medications were removed by contractors. However liquid and Class B controlled drugs were predominantly disposed of down the pharmacy sink. Over 60% of the participating pharmacists indicated that they believed the contractors incinerated the collected pharmaceutical waste, and over 90% of the participating pharmacists indicated their wish for a state-run disposal and destruction system. DISCUSSION: Liquid medications and Class B controlled drugs, which were commonly reported to be disposed of down the sewage system, may increase the potential for environmental pollution by pharmaceuticals in New Zealand. There is a need for increased environmental awareness amongst community pharmacists in New Zealand.


Subject(s)
Medical Waste Disposal/methods , Pharmaceutical Preparations , Pharmacists , Adult , Aged , Aged, 80 and over , Environmental Pollution/prevention & control , Female , Humans , Male , Middle Aged , New Zealand , Surveys and Questionnaires
7.
Environ Int ; 37(1): 292-8, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20970194

ABSTRACT

Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peer-reviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world.


Subject(s)
Pharmaceutical Preparations , Refuse Disposal/methods , Waste Products/statistics & numerical data , Public Opinion
8.
Anal Chim Acta ; 653(2): 191-9, 2009 Oct 27.
Article in English | MEDLINE | ID: mdl-19808113

ABSTRACT

A comparison is presented of six methods involving nitric acid in conjunction with other reagents to digest three certified marine biological samples (DOLT-3, DORM-3, IAEA-407) and a fish bone homogenate (prepared from Merluccius australis). An inductively coupled plasma-mass spectrometer with an octopole collision cell was used to determine up to 40 elements (Li, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Y, Ag, Cd, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Pb, Th, U) in the digests. These results were assessed in terms of their accuracy and precision, and a flow chart was developed to aid the selection of the optimal digestion method. Although none of the methods was found to give accurate determinations for all elements in the different reference materials, a relatively simple method involving nitric acid and hydrogen peroxide heated in a domestic microwave oven gave the most acceptable results.


Subject(s)
Analytic Sample Preparation Methods/methods , Gadiformes , Trace Elements/analysis , Animals , Bone and Bones/chemistry , Mass Spectrometry , Sensitivity and Specificity , Trace Elements/metabolism
9.
Environ Int ; 35(6): 952-5, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19423167

ABSTRACT

BACKGROUND: There is an enhanced international awareness that the improper disposal of unwanted and unused medications may have a detrimental effect on the environment. OBJECTIVES: The aim of this study was to determine the proportion of unused medications in New Zealand that are not returned to a pharmacy for disposal and are instead disposed of via land fill or water systems. In addition, this study intended to identify why these medications were unused or unwanted. DESIGN: An online survey was placed on the New Zealand National Poisons Centre website for a period of three months during 2008. This consisted of a series of questions with predefined answer sets and asked about collection of medications, why there may be unused medications, storage of medications and disposal of medications. RESULTS: This survey was completed by 452 individuals. 62% of respondents currently had unwanted medications in their house. The most common reason for people to have leftover medication was 'medical condition improved or resolved' (n=307). Depending on formulation type, between 13-24% of unused medications were returned to pharmacies with tablets and capsules being most likely to be returned and liquids most likely to be added to water systems. CONCLUSIONS: A significant percentage of unwanted medications are disposed of via routes that have the potential to adversely affect the environment. Reducing excess medications and wastage as well as education of appropriate disposal techniques may minimize their potential impact on the environment.


Subject(s)
Pharmaceutical Preparations , Refuse Disposal/methods , Refuse Disposal/statistics & numerical data , Humans , New Zealand , Surveys and Questionnaires
10.
Environ Sci Technol ; 43(3): 698-703, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-19245004

ABSTRACT

Sunlight-induced molecular changes have been observed in two samples of dissolved organic matter (DOM) collected in the Cape Fear River system, North Carolina, USA. The molecular composition of a water sample collected in the Black River (sample B210, salinity 0) and another water sample collected within the Cape Fear River estuary (sample M61, salinity 13.7) were analyzed using an ultrahigh resolution 9.4 Tesla (T) electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer. Additionally, the Ultraviolet/Visible (UV/vis) absorbance as well as the excitation emission matrix (EEM) fluorescence spectra were determined to identify changes in the optical properties associated with photochemical reactions of the chromophoric DOM (CDOM). The molecular formulas forthe Cape Fear River Estuary (M61) sample before the irradiation experiments indicated the presence of highly aromatic compounds which were not present in the unirradiated Black River sample (B210). These aromatic compounds, with oxygen-subtracted double bond equivalents (DBE-O) values greater than nine, are more photoreactive and readily photodegraded relative to saturated compounds. Compounds with DBE-O values below nine are less photoreactive. The UV/vis absorbance and EEM fluorescence results supported this different photodegradation behavior, suggesting that the photoreactivity of CDOM is highly dependent on the molecular composition of the CDOM.


Subject(s)
Fourier Analysis , Mass Spectrometry/methods , Cyclotrons , Photochemistry , Spectrophotometry, Ultraviolet
11.
Water Res ; 43(3): 635-42, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19054538

ABSTRACT

N,N'-Diethyl-m-toluamide (DEET) is widely used as an insect repellent and has therefore been detected as a contaminant in numerous waste and surface waters. In this study we have determined the absolute reaction rate constants of DEET with the hydroxyl radical and the hydrated electron in aqueous solution as (4.95+/-0.18)x10(9) and (1.34+/-0.04)x10(9) M(-1) s(-1), respectively, using pulse radiation. To provide additional information on the radicals formed upon oxidation, transient spectra were measured from 1 to 150 micros, with transient decay rates determined from the time-dependence of the maximum absorption at 330 nm. These data suggest simple decay of the initially formed radical to stable products. Radical-based destruction mechanisms for destruction of DEET are proposed based on the LC-MS determination of the stable compounds produced by 60Co gamma-irradiation of DEET solutions. These data will be useful in evaluating potential advanced oxidation/reduction processes for the control of DEET and understanding its fate and transport in surface water where analogous radical chemistry is operative.


Subject(s)
DEET/chemistry , Free Radicals/chemistry , Chromatography, Liquid , Kinetics , Mass Spectrometry , Oxidation-Reduction , Solutions , Spectrum Analysis
12.
Environ Sci Technol ; 42(4): 1256-61, 2008 Feb 15.
Article in English | MEDLINE | ID: mdl-18351102

ABSTRACT

Many pharmaceutical compounds and metabolites are currently found in surface and ground waters which indicates their ineffective removal by conventional water treatment technologies. Advanced oxidation/reduction processes (AO/ RPs) are alternatives to traditional water treatment, which utilize free radical reactions to directly degrade chemical contaminants. This study reports the absolute rate constants for reaction of three beta-blockers (atenolol, metoprolol, and propranolol) with the two major AO/RP radicals; the hydroxyl radical (*OH) and hydrated electron ((e-)aq). The bimolecular reaction rate constants for *OH are (7.05 +/- 0.27) x 10(9), (8.39 +/- 0.06) x 10(9), and (1.07 +/- 0.02) x 10(10), and for (e-)aq they are (5.91 +/- 0.21) x 10(8), (1.73 +/- 0.03) x 10(8), and (1.26 +/- 0.02) x 10(10), respectively. Transient spectra were observed for the intermediate radicals produced by hydroxyl radical reactions. In addition, preliminary degradation mechanisms and major products were elucidated using 60Co gamma-irradiation and LC-MS. These data are required for both evaluating the potential use of AO/RPs for the destruction of these compounds and for studies of their fate and transport in surface waters where radical chemistry may be important in assessing their lifetime.


Subject(s)
Adrenergic beta-Antagonists/chemistry , Free Radicals/chemistry , Kinetics , Solutions , Water
13.
Anal Chem ; 79(11): 4169-76, 2007 Jun 01.
Article in English | MEDLINE | ID: mdl-17455905

ABSTRACT

Chemiluminescence (CL) of acridinium esters (AE) has found widespread use in analytical chemistry. Using the mechanism of the reaction of H2O2 with 10-methyl-9-(p-formylphenyl)acridinium carboxylate trifluoromethanesulfonate and a modified flow injection system, the reaction rates of each step in the mechanism were evaluated and used in a kinetic model to optimize the analysis of H2O2. Operational parameters for a flow injection analysis system (reagent pH, flow rate, sample volume, PMT settings) were optimized using the kinetic model. The system is most sensitive to reaction pH due to competition between AE hydrolysis and CL. The optimized system was used to determine H2O2 concentrations in natural waters, including rain, freshwater, and seawater. The lower limit of detection varied in natural waters, from 352 pM in open ocean seawater (mean, 779 pM +/- 15.0%, RSD) to 58.1 nM in rain (mean, 6,340 nM +/- 0.92%, RSD). The analysis is specific for H2O2 and is therefore of potential interest for atmospheric chemistry applications where organoperoxides have been reported in the presence of H2O2.


Subject(s)
Acridines/chemistry , Esters/chemistry , Flow Injection Analysis/methods , Hydrogen Peroxide/analysis , Luminescent Measurements/methods , Models, Chemical , Water/analysis , Earth, Planet , Fresh Water , Hydrolysis , Kinetics , Molecular Structure , Rain , Seawater , Solutions
14.
Environ Monit Assess ; 115(1-3): 119-44, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16705355

ABSTRACT

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993-1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (microg g(-1) dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3-60 microg g(-1) for Cu, 40-118 microg g(-1) for Zn, 2-12 microg g(-1) for Mn, 5-35 microg g(-1) for Ni and 1-44 microg g(-1) for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.


Subject(s)
Cardiidae/chemistry , Environmental Monitoring/methods , Metals, Heavy/analysis , Trace Elements/analysis , Animals , Body Weight/drug effects , Metals, Heavy/toxicity , New Zealand , Seasons , Seawater/chemistry , Trace Elements/toxicity
15.
Sci Total Environ ; 359(1-3): 145-55, 2006 Apr 15.
Article in English | MEDLINE | ID: mdl-16014309

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals were measured in road debris collecting in urban areas and in the suspended sediment (SS) component of runoff from two stormwater catchments in Dunedin, New Zealand. Levels in the road debris ranged from 119-527 microg/g for lead, 50-464 microg/g for copper, 241-1 325 microg/g for zinc and 1.20-11.6 microg/g for sigma16PAH. The SS from the largely rural catchment (20% urban) had similar concentrations to the road debris, indicating that this urban material was the main source of the contaminants measured in the stormwater. Similar PAH fingerprint profiles and isomer ratios indicative of dominant pyrogenic (combustion) sources were also found in these two groups of materials. The SS from the 100% urban catchment contained 2- to 6-fold higher concentrations of metals and 10-fold greater levels of sigma16PAH. The higher levels of lead and copper were probably a result of industrial land uses in this catchment, while the additional zinc was linked to an abundance of zinc-galvanised roofing iron in the catchment's residential suburbs. The PAH profiles and isomer ratios were different for this urban catchment and suggested that a disused gasworks was contributing PAHs to the stormwater runoff.


Subject(s)
Copper/analysis , Lead/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Water Pollutants, Chemical/analysis , Zinc/analysis , Environmental Monitoring , New Zealand , Rain , Water Movements , Water Supply/analysis
16.
Environ Toxicol Pharmacol ; 20(1): 175-81, 2005 Jul.
Article in English | MEDLINE | ID: mdl-21783586

ABSTRACT

The tricarboxylic neurotoxin domoic acid (DA) binds trace metals such as iron and copper. In vitro brain slice recording (area CA1 of rat hippocampal slices) was used to assess changes in DA potency in the presence of cadmium and zinc. Cadmium or zinc alone had little or no effect on CA1 responses. DA alone produced hyperexcitability and, with prolonged administration, a robust suppression of CA1 responses. Coadministration of DA with either 2 or 4µM Cd(2+) produced significant reductions in the potency of DA; less striking effects were seen in the presence of 4µM Zn(2+). These findings suggest that interactions of Cd(2+) and Zn(2+) with DA result in the formation of trace metal-neurotoxin complexes which are either unavailable for binding to ionotropic glutamate receptors, or bind without producing full agonist activity.

17.
Environ Int ; 30(5): 631-7, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15051239

ABSTRACT

A study was undertaken to determine whether the isotopic ratios of C and N could be used to uniquely identify municipal solid waste landfill leachate as a source of contamination in the Kaikorai Estuary, Dunedin, New Zealand. Leachate samples were taken from the adjacent Green Island Landfill (GILF), and surface water samples were collected over an 8-month period from the stream and estuary, upstream and downstream of the landfill. Samples were analysed for delta(13)C-dissolved inorganic carbon (DIC), delta(15)N-NO(3)(-), delta(15)N-NH(4)(+), and particulate organic matter (POM) delta(13)C and delta(15)N. Plant material collected along the Kaikorai Stream was analysed for POM delta(13)C and delta(15)N. Leachate was found to have a distinct isotopic signature characterised by a highly enriched delta(13)C-DIC (as much as 16.11+/-0.23 per thousand ) and highly enriched delta(15)N-NH(4)(+) (as much as 27.42+/-0.90 per thousand ). Evidence of leachate contamination was found in the isotopic signatures of downstream delta(13)C-DIC, delta(15)N-NH(4)(+), and delta(13)C and delta(15)N of plant material POM. Other potential sources of enriched delta(13)C-DIC and delta(15)N-NH(4)(+) present in the study area, such as estuarine waters and livestock effluent, were eliminated on the basis of their isotopic characteristics.


Subject(s)
Environmental Monitoring/methods , Refuse Disposal , Water Pollutants/analysis , Animals , Animals, Domestic , Carbon Isotopes/analysis , New Zealand , Nitrogen Isotopes/analysis , Plants , Solubility
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