A method for the extraction of microplastics from solid biowastes including biosolids, compost, and soil for analysis by µ-FTIR.

Few methods exist detailing the extraction of microplastics from organic matrices. A validated method for the successful extraction of microplastics from solid biowastes including biosolids, compost, and soil for spectroscopic analysis by micro-Fourier transform infrared spectroscopy (µ-FTIR) was developed. Solid dry biowastes were first digested with a wet peroxide oxidation (WPO) with iron (II) solution and 30% hydrogen peroxide followed by sequential density separations with ultra-pure water and 1.8 g cm-3 NaI in an optimised sediment-microplastic isolation (SMI) unit. The average recoveries for spiked microplastics were 92, 95 and 98% for bagged compost, biosolids, and soil, respectively. This method ensures a high microplastic recovery by first chemically disintegrating biowaste aggregates without employing destructive methods like milling and allows for successful density separations where the settled fraction is isolated off from the supernatant, allowing thorough rinsing of the equipment and thus a greater transferal of particles into the vacuum filtering device. Minimal processing steps reduce the instance of introducing contamination and particle loss.•Digestion as a first step to disintegrate aggregates to release entrapped microplastics•Density separation with SMI unit with the method adapted for biowastes•Minimal steps to reduce contamination and particle loss.

Chemical elements in Elaeis guineensis materials and derived oil.

The production of oil palm (Elaeis guineensis) in Southeast Asia is vital to the economies of Indonesia and Malaysia. Both fertilisers and pesticides used in palm production can contain elevated concentrations of Trace Elements (TEs) which may accumulate in soils and leaf tissues of plants. We hypothesised that leaves from oil palms may be deficient in essential elements, while containing elevated concentrations of non-essential TEs commonly found in agrichemicals. Samples of plant materials (leaves and fruitlets) were collected from active and former plantations in Sumatra, Indonesia, and analysed for essential and non-essential elements. Indonesian palm oil samples were sourced in New Zealand and their elemental concentrations determined. Leaf materials from both active and abandoned production sites were deficient in N, K, S and Mo, while leaf materials from abandoned sites were deficient in P. These deficiencies may have been a contributing factor to the abandonment of production at these sites. Concentrations of non-essential elements were below or comparable to average plant concentrations and no evidence of contamination was found in plant tissues. Palm oil contained low concentrations of TEs, which did not pose any toxicity risks. However, Na and Al were present in concentrations of 1198 and 159 mg kg-1 respectively, which were higher than have been previously reported. Tropical oil palm production could benefit from the determination of bioaccumulation factors for fertiliser contaminants in E. guineensis, to limit the transfer of contaminants to plants and products if increased fertiliser applications were used to correct nutrient deficiencies.

Leaching and transformation of chemical additives from weathered plastic deployed in the marine environment.

Plastic pollution causes detrimental environmental impacts, which are increasingly attributed to chemical additives. However, the behaviour of plastic additives in the marine environment is poorly understood. We used a marine deployment experiment to examine the impact of weathering on the extractables profile, analysed by liquid chromatography-mass spectrometry, of four plastics at two locations over nine months in Aotearoa/New Zealand. The concentration of additives in polyethylene and oxo-degradable polyethylene were strongly influenced by artificial weathering, with deployment location and time less influential. By comparison, polyamide 6 and polyethylene terephthalate were comparatively inert with minimal change in response to artificial weathering or deployment time. Non-target analysis revealed extensive differentiation between non-aged and aged polyethylene after deployment, concordant with the targeted analysis. These observations highlight the need to consider the impact of leaching and weathering on plastic composition when quantifying the potential impact and risk of plastic pollution within receiving environments.

The Uptake of Rare Trace Elements by Perennial Ryegrass (Lolium perenne L.).

Technological development has increased the use of chemical elements that have hitherto received scant scientific attention as environmental contaminants. Successful management of these rare trace elements (RTEs) requires elucidation of their mobility in the soil-plant system. We aimed to determine the capacity of Lolium perenne (a common pasture species) to tolerate and accumulate the RTEs Be, Ga, In, La, Ce, Nd, and Gd in a fluvial recent soil. Cadmium was used as a reference as a well-studied contaminant that is relatively mobile in the soil-plant system. Soil was spiked with 2.5-283 mg kg-1 of RTE or Cd salts, representing five, 10, 20, and 40 times their background concentrations in soil. For Be, Ce, In, and La, there was no growth reduction, even at the highest soil concentrations (76, 1132, 10.2, and 874 mg kg-1, respectively), which resulted in foliar concentrations of 7.1, 12, 0.11, and 50 mg kg-1, respectively. The maximum no-biomass reduction foliar concentrations for Cd, Gd, Nd, and Ga were 0.061, 0.1, 7.1, and 11 mg kg-1, respectively. Bioaccumulation coefficients ranged from 0.0030-0.95, and increased Ce < In < Nd ≅ Gd < La ≅ Be ≅ Ga < Cd. Beryllium and La were the RTEs most at risk of entering the food chain via L. perenne, as their toxicity thresholds were not reached in the ranges tested, and the bioaccumulation coefficient (plant/soil concentration quotient) trends indicated that uptake would continue to increase at higher soil concentrations. In contrast, In and Ce were the elements least likely to enter the food chain. Further research should repeat the experiments in different soil types or with different plant species to test the robustness of the findings.

Impact of accelerated weathering on the leaching kinetics of stabiliser additives from microplastics.

The release of additives from microplastics is known to harm organisms. In the environment, microplastics are exposed to weathering processes which are suspected to influence additive leaching kinetics, the extent and mechanism of which remain poorly understood. We examined the impact of weathering on stabiliser additive leaching kinetics using environmentally relevant accelerated weathering and leaching procedures. Nine binary polymer-additive formulations were specifically prepared, weathered, analysed, and evaluated for their leaching characteristics. Cumulative additive release (Ce) varied widely between formulations, ranging from 0.009 to 1162 µg/g. Values of Ce generally increased by polymer type in the order polyethylene terephthalate < polyamide 6 < polyethylene. The change in leaching kinetics after accelerated weathering was incongruous across the nine formulations, with a significant change in Ce only observed for three out of nine formulations. Physicochemical characterisation of the microplastics demonstrated that additive blooming was the primary mechanism influencing the leaching response to weathering. These findings highlight the dependency of additive fate on the polymer type, additive chemistry, and the extent of weathering exposure. This has significant implications for risk assessment and mitigation, where the general assumption that polymer weathering increases additive leaching may be too simplistic.

Solving a microplastic dilemma? Evaluating additive release with a dynamic leaching method for microplastic assessment (DyLeMMA).

Microplastics and plastic additives are contaminants of emerging environmental concern. Static leaching methods are commonly applied to assess the rate and extent of additive release from microplastics. However, this approach may not be representative of environmental conditions where near infinite dilution or percolation commonly occur. We evaluated three different approaches for assessing additive leaching under environmentally relevant sink conditions, culminating in the refinement and validation of DyLeMMA (Dynamic Leaching Method for Microplastic Assessment). Analysis was performed using a high-resolution liquid chromatography-mass spectrometry method enabling targeted quantification of additives and screening for non-intentionally added substances. Using four different plastics, sink conditions were maintained over the duration of the test, thereby avoiding solubility limited release and ensuring environmental relevance. Background contamination from ubiquitous additive chemicals was minimised, thereby providing good sensitivity and specificity. Resulting data, in the form of additive release curves, should prove suitable for fitting to release models and derivation of parameters describing additive leaching from microplastics.Key attributes of DyLeMMA:•Environmentally relevant dynamic leaching method for microplastics, demonstrated to maintain sink conditions over the test duration,•Simple, fast, and cost-effective approach without complication of using a solid phase sink,•Provide data suitable for understanding microplastic leaching kinetics and mechanisms.

Physiological and biochemical responses of the estuarine pulmonate mud snail, Amphibola crenata, sub-chronically exposed to waterborne cadmium.

Physiological and biochemical responses of the pulmonate mud snail, Amphibola crenata, to waterborne cadmium (Cd) were investigated to determine the mechanisms of toxicity and impacts of a 21-d Cd exposure. Mud snails were exposed to nominal Cd concentrations of 0, 0.2, 4 and 8 mg L - 1 and bioaccumulation, whole animal physiological (oxygen consumption, ammonia excretion and oxygen:nitrogen), and tissue level biochemical (catalase activity, lipid peroxidation, glycogen, glucose and protein) endpoints were measured every 7 days. At the two highest Cd exposure concentrations complete mortality was observed over 21-d. In surviving animals, oxygen consumption declined and ammonia excretion rate increased with Cd exposure concentration and duration. The increased ammonia excretion likely reflected enhanced protein metabolism as suggested by a reduced oxygen:nitrogen (O:N). Increasing waterborne Cd concentration and exposure time led to increasing metal accumulation in all tissues. The snail viscera showed the highest Cd accumulation. Both catalase activity and lipid peroxidation in the viscera significantly increased with Cd exposure concentration and time, whereas, the foot muscle and remaining tissues (kidney, mantle, remaining digestive tissues and heart) showed increased catalase activity and lipid peroxidation at higher Cd concentrations (4 and 8 mg L - 1), suggestive of an effect of Cd on oxidative stress. Over the course of 21 days, Cd exposure resulted in significantly lower levels of glycogen in viscera relative to Cd-free controls, reflecting an increased energy demand. Haemolymph glucose rose initially and then fell with increased exposure duration, while haemolymph protein generally exhibited an increased concentration in Cd-exposure groups, reflecting the changes in energy substrates noted for somatic tissues. These results suggest that the physiological and biochemical responses of A. crenata to Cd are conserved relative to other aquatic animals, and were tissue-specific, dose- and time-dependant.

The relationship between population attributes of the mud snail Amphibola crenata and sediment contamination: A multi-estuary assessment.

This study assessed the potential of the New Zealand mud snail Amphibola crenata to act as a bioindicator of contaminated estuarine sediment. Seventeen sites with varying contaminant burdens were identified within six New Zealand regions. Attributes (population density, individual length distribution and individual dry weight condition index) were measured for field-collected A. crenata, and related to measurements of sediment trace metals and nutrients. Population density of the mud snail was relatively high in sites with elevated nutrients and organic matter. The length distribution of A. crenata showed significant regional and site-specific variations. Minimum, mean, and median shell length of A. crenata were positively correlated with sediment cadmium and zinc concentration. Overall, the sites were able to be distinguished by A. crenata population attributes and the sediment metal and nutrient content. These results suggest that A. crenata population information has potential value for assessing estuarine sediment metal and nutrient contamination.

Radium in New Zealand agricultural soils: Crop uptake and estimation of current and future ionising radiation dose.

Crop uptake of 226Ra over a range of key New Zealand agricultural and horticultural growing areas was analysed to establish the dietary implications of an increase in soil 226Ra activity concentrations. Thirty crop samples, covering both feed and food commodities, were quantified for 226Ra activity concentrations, and concentration ratio (CRs) from the soil activity were calculated. The calculated CRs correlated with international default values for estimating crop uptake. Variation in CRs established that there was no increase in the crop activity concentration, relative to soil 226Ra from pasture foliage at a fertiliser impacted site, with a gradient of soil 226Ra activity concentrations. Based on the calculated CRs, the upper bound of the theoretical range of dietary exposures to 226Ra was 78.1 µSv/yr for teenage boys. Future forecasting of the increased dietary dose of 226Ra that might occur at the current soil loading rate, based on current fertiliser activity concentrations, confirmed that long-term loading of soil with 226Ra is unlikely to present a dietary risk. The forecast model calculated that the increase in dietary ionising radiation burden is unlikely to reach thresholds requiring regulatory intervention for two millennia.

Dose assessment for polonium-210 (Po-210) in New Zealand shellfish.

Worldwide, Po-210 is an important contributor to human ionising radiation exposure through food. To characterise the ionising radiation dose for New Zealanders from Po-210 in shellfish, a dose assessment was undertaken. Deterministic and probabilistic dietary models were constructed by assigning shellfish consumption rates to Po-210 activity concentrations measured in shellfish. Modelling was undertaken for different shellfish consumer populations and geographical areas. Dietary modelling estimated an annual dose range from 4 µSv to 6070 µSv. The lowest dose was calculated for the overall shellfish consumer population residing in areas where baseline Po-210 activity concentrations were measured in shellfish. The highest dose was calculated for the high shellfish consumer population residing in areas where elevated activity concentrations were measured in shellfish. For the majority of the New Zealand population, the total estimated dose did not exceed the selected reference level of 1000 µSv, and Po-210 is therefore not a cause of concern. About 50% of high shellfish consumers residing in areas where shellfish had elevated Po-210 activity concentrations were exposed to ionising radiation resulting in an annual dose higher than 1000 µSv. Exposure assessment for different demographic groups identified that higher shellfish consumption rates in the population identifying as Maori lead to higher doses of ionising radiation for this group.

Direct radiative effects of airborne microplastics.

Microplastics are now recognized as widespread contaminants in the atmosphere, where, due to their small size and low density, they can be transported with winds around the Earth1-25. Atmospheric aerosols, such as mineral dust and other types of airborne particulate matter, influence Earth's climate by absorbing and scattering radiation (direct radiative effects) and their impacts are commonly quantified with the effective radiative forcing (ERF) metric26. However, the radiative effects of airborne microplastics and associated implications for global climate are unknown. Here we present calculations of the optical properties and direct radiative effects of airborne microplastics (excluding aerosol-cloud interactions). The ERF of airborne microplastics is computed to be 0.044 ± 0.399 milliwatts per square metre in the present-day atmosphere assuming a uniform surface concentration of 1 microplastic particle per cubic metre and a vertical distribution up to 10 kilometres altitude. However, there are large uncertainties in the geographical and vertical distribution of microplastics. Assuming that they are confined to the boundary layer, shortwave effects dominate and the microplastic ERF is approximately -0.746 ± 0.553 milliwatts per square metre. Compared with the total ERF due to aerosol-radiation interactions27 (-0.71 to -0.14 watts per square metre), the microplastic ERF is small. However, plastic production has increased rapidly over the past 70 years28; without serious attempts to overhaul plastic production and waste-management practices, the abundance and ERF of airborne microplastics will continue to increase.

Chemical Elements and the Quality of Manuka (Leptospermum scoparium) Honey.

Soil properties in the foraging range of honeybees influence honey composition. We aimed to determine relationships between the antimicrobial properties of New Zealand manuka (Leptospermum scoparium) honey and elemental concentrations in the honey, plants, and soils. We analyzed soils, plants, and fresh manuka honey samples from the Wairarapa region of New Zealand for the chemical elements and the antimicrobial activity of the honey as indicated by methylglyoxal (MGO) and dihydroxyacetone (DHA). There were significant negative correlations between honey MGO and the concentrations of Mn, Cu, Mg, S, Na, Ba, K, Zn, and Al. These elements may provide a low-cost means of assessing manuka honey quality. For individual elements, except for K, there were no correlations between the honeys, plants, and soils. Soil nitrate concentrations were negatively correlated with concentrations of MGO and DHA in the honey, which implies that soil fertility may be a determiner of manuka honey quality.

Leaching and extraction of additives from plastic pollution to inform environmental risk: A multidisciplinary review of analytical approaches.

Plastic pollution is prevalent worldwide and has been highlighted as an issue of global concern due to its harmful impacts on wildlife. The extent and mechanism by which plastic pollution effects organisms is poorly understood, especially for microplastics. One proposed mechanism by which plastics may exert a harmful effect is through the leaching of additives. To determine the risk to wildlife, the chemical identity and exposure to additives must be established. However, there are few reports with disparate experimental approaches. In contrast, a breadth of knowledge on additive release from plastics is held within the food, pharmaceutical and medical, construction, and waste management industries. This includes standardised methods to perform migration, extraction, and leaching studies. This review provides an overview of the approaches and methods used to characterise additives and their leaching behaviour from plastic pollution. The limitations of these methods are highlighted and compared with industry standardised approaches. Furthermore, an overview of the analytical strategies for the identification and quantification of additives is presented. This work provides a basis for refining current leaching approaches and analytical methods with a view towards understanding the risk of plastic pollution.

Spatial and temporal change in trace element profiles in seawater, sediment and mussels associated with an earthquake rubble sea-fill.

Elemental profiles in seawater, sediment and green-lipped mussels (Perna canaliculus) were determined, following the deposition of earthquake demolition rubble into a newly developed sea-fill located adjacent to a busy commercial port with a history of diverse contaminant inputs. Zinc and lead displayed environmental concentrations that varied over time during sea-fill construction, and which declined with distance from the sea-fill, indicating that the sea-fill activity was the source of these two contaminants. A transplantation study using reference site mussels caged near the sea-fill, supported this finding. However, none of the trace metal burdens in resident or transplanted mussels were of regulatory concern. An integrated approach comprising the monitoring of multiple environmental matrices, examination of contaminant burdens as a function of time and distance from a putative point source, and the use of active biomonitoring techniques, is necessary to robustly identify novel contamination inputs in historically-polluted marine settings.

Organic Micropollutants in Wastewater Effluents and the Receiving Coastal Waters, Sediments, and Biota of Lyttelton Harbour (Te Whakaraupo), New Zealand.

Coastal ecosystems are receiving environments for micropollutants due to high levels of associated anthropogenic activities. Effluent discharges from wastewater treatment plants are a significant source of micropollutants to coastal environments. Wastewater effluents, seawater, sediments, and green-lipped mussels (Perna canaliculus) in Lyttelton Harbour (Te Whakaraupo), Christchurch, New Zealand, were analysed for a suite of personal care products and steroid hormones during a 1-year period. In wastewater effluents, the concentration of methyl paraben (mParaben), ethyl paraben (eParaben), propyl paraben (pParaben), butyl paraben (bParaben), 4-t-octylphenol (OP), 4-methylbenzylidene camphor (4-MBC), benzophenone-3 (BP-3), benzophenone-1 (BP-1), triclosan, methyl triclosan (mTric), Bisphenol A (BPA), Estrone (E1), 17ß-estradiol (E2), 17α-ethinyl estradiol (EE2), and Estriol (E3) ranged from < 0.6 to 429 ng L-1 and was dominated by OP, 4-MBC, BP-3, triclosan, BP-1, and BPA. In seawater, 4-MBC, BP-3, BPA, and E1 were the most frequently detected contaminants (< 0.2-9.4 ng L-1). Coastal sediment samples contained mParaben, OP, 4-MBC, BP-3, BP-1, BPA, OMC, and E1 (< 0.2-11 ng g-1 d.w.), and mParaben, OP, and BP-3 were found to bioaccumulate (3.8-21.3 ng g-1 d.w.) in green lipped mussels.

Latitudinal, sex and inter-specific differences in mercury and other trace metal concentrations in Adélie and Emperor penguins in the Ross Sea, Antarctica.

We sought to determine mercury (Hg) and other trace metal concentrations in Adélie (Pygoscelis adeliae) and emperor penguin (Aptenodytes forsteri) breast feathers from the Ross Sea, Antarctica, and relate those concentrations to the trophic position and the habitats in which each of these species forage. Adélie penguin feathers from the southern Ross Sea colonies were higher in Hg than those sampled further north in the Ross Sea, potentially due to greater exposure to local sources, such as volcanism. Female Adélie penguins had lower feather total Hg concentrations than males. This may reflect female penguin's capacity to eliminate Hg through the egg development and laying process, or the larger and/or older prey items that male birds can consume, reflected by their higher trophic position. Emperor penguins have higher Hg concentrations than Adélie penguins which is also partially explained by Adélie penguins feeding at lower trophic levels than emperor penguins.

Microplastic contamination in Auckland (New Zealand) beach sediments.

We report the first large-scale investigation of microplastic contamination in beach sediments across Auckland, New Zealand's most populous region. Sediment samples were taken from the high tide and intertidal zones at 39 sites across estuary, harbour and ocean environments of the East and West Coasts. Microplastic contamination was present at the majority of beaches studied with a mean abundance of 459 particles.m-2 ranging from 0 to 2615 particles.m-2. High variability was observed between the sites, indicating the importance of small-scale factors on microplastic contamination. Samples from high and intertidal zones showed no significant difference in microplastic contamination (p = 0.225). The West Coast beaches exhibited higher microplastic contamination compared with East Coast beaches (p = 0.004). Microplastics were predominately fibres (88%), with lower proportions of fragments (8%) and films (4%). The majority of the microplastics analysed were regenerated cellulose (34%), polyethylene terephthalate (22%) and polyethylene (15%).

Spatial variability in Polonium-210 and Lead-210 activity concentration in New Zealand shellfish and dose assessment.

The activity concentrations of Polonium-210 (210Po) and Lead-210 (210Pb) were determined in shellfish (Perna canaliculus and Paphies subtriangulata) sampled bimonthly from March 2018 to February 2019 from 14 sites around New Zealand. Activity concentrations of 210Po ranged from 4.7 ±â€¯1.1 to 324 ±â€¯17 Bq. kg-1 with a mean value of 57 ±â€¯72 Bq. kg-1 (wet weight). The activity concentrations of 210Pb were lower than those for 210Po (0.1 ±â€¯0.4 and 1.9 ±â€¯0.4 Bq. kg-1, with a mean value of 0.7 ±â€¯0.4 Bq. kg-1, wet weight). The calculated 210Po/210Pb activity concentration ratios were higher than unity in all samples indicating that radionuclides are not in equilibrium in shellfish and most of the 210Po was unsupported by its grandparent 210Pb. No significant difference was noted in 210Po activity concentration between different seasons, species or shellfish condition index. Significant spatial variability in 210Po activity concentration was observed with elevated 210Po activity concentration in two sampling sites: Ninety Mile Beach (mean 257 ±â€¯47 Bq. kg-1) and Maunganui Bluff (mean 127 ±â€¯22 Bq. kg-1). Elevated 210Po is hypothesised to be related to an increase of 210Po accumulation through diet. Individuals who consume large quantities of shellfish (10 g per day or more) from areas affected by elevated 210Po activity concentration may be exposed to an annual committed effective dose from 210Po in shellfish in excess of 1 mSv.

Assessing the Efficacy of a Sediment Remediation Program Using Benthic and Pelagic Copepod Bioassays.

Tributyltin is an organotin chemical that has been commonly used in ship antifouling paints. Despite the global total prohibition of tributyltin-based paint in 2008, tributyltin continues to be found at toxic levels in areas of high maritime traffic such as ports and harbors. A remediation program was conducted at a New Zealand port to reduce tributyltin and copper concentrations to acceptable values. The present study assessed the efficacy of the program using a combination of chemical analyses and copepod bioassays. Sediment and water samples were collected at 3 locations along a spatial gradient within the port, and concentrations of various organotin compounds and trace metal levels were measured pre- and postremediation. The toxicity of sediment and elutriate samples was estimated by benthic and pelagic copepod bioassays. Although acute toxicity in sediment samples was reduced following remediation, reproductive success was still affected for the benthic copepod. This approach combining chemical analysis and bioassays is promising for assessing the efficacy of remediation processes at contaminated marine sites. Environ Toxicol Chem 2020;39:492-499. © 2019 SETAC.

Environmental Parameters Affecting the Concentration of Iodine in New Zealand Pasture.

Iodine (I) is an essential trace element commonly deficient in agricultural systems. Whereas there is much information on I in food crops, there is a lacuna of knowledge on the environmental factors that affect pasture I concentrations. We aimed to identify the most important environmental factors affecting the concentration of I in New Zealand pastures, and the consequences to agricultural systems. Soil and pastoral samples were collected throughout the country and analyzed for I and other elements. The soils contained 1.1 to 86 mg I kg, with 0.005 to 1.4 mg kg in the pasture. In 26% of pastures, I concentrations were insufficient for sheep nutrition, whereas 87% contained insufficient I for cattle nutrition. Pasture I concentrations were negatively correlated with the distance from the sea, and the concentration of oxalate-extractable amorphous Al, Fe, and Si oxides, which immobilize soil I. Soil organic C and clay increased I retention in soil but did not significantly affect pasture I concentrations. Future work should investigate how soil properties affect pasture I uptake in inland areas.