Assessing daily patterns in stimulant use during the COVID-19 pandemic in Melbourne, Australia using wastewater analysis.

During the COVID-19 pandemic, one of Australia's biggest cities, Melbourne, experienced three major isolation ("lockdown") periods in 2020 (160 days) and in 2021 (111 days) which makes it one of the most locked down cities world-wide. This study assessed how the pandemic affected temporal trends in methamphetamine, MDMA and cocaine consumption using wastewater-based epidemiology. Daily samples were collected for most of 2020 and 2021 (n = 660 days). Concentrations were measured using direct-injection LC-MS/MS and back-calculated to consumption estimates. Results indicate that methamphetamine use was increasing before the first lockdown and decreased after the end of the first lockdown in 2020. Methamphetamine trends appeared to have remained steady throughout the second lockdown period before increasing steeply after it ended. For most of 2020, cocaine use remained steady, with an increase after the second lockdown. MDMA use decreased after the start of the first lockdown and remained steady throughout most of 2020 and 2021. In comparison to 2020, trends in 2021 were less variable and stimulant use did not appear to be as associated with COVID-19 restrictions. Overall, this study was able to show the impact of lockdown periods and the related social restrictions on illicit stimulant use. ENVIRONMENTAL IMPLICATION: Illicit drugs are hazardous chemicals, of concern both to humans and the environment. While studies have been undertaken to understand their temporal trends, this work utilizes wastewater-based epidemiology and daily sampling to provide a comprehensive understanding of the impact of the COVID-19 pandemic on the use of methamphetamine, MDMA and cocaine on one of the most locked-down cities in the world. Understanding the consequences of this significant intervention on illicit drug use could provide valuable insights into its potential environmental impact.

High throughput and sensitive quantitation of tobacco-specific alkaloids and nitrosamines in wastewater.

Tobacco-specific alkaloids and nitrosamines are important biomarkers for the estimation of tobacco use and human exposure to tobacco-specific nitrosamines that can be monitored by wastewater analysis. Thus far their analysis has used solid phase extraction, which is costly and time-consuming. In this study, we developed a direct injection liquid chromatography-tandem mass spectrometry method for the quantification of two tobacco-specific alkaloids and five nitrosamines in wastewater. The method achieved excellent linearity (R2 > 0.99) for all analytes, with calibration ranging from 0.10 to 800 ng/L. Method limits of detection and quantification were 0.17 ng/L (N-nitrosonornicotine, NNN) and 1.0 ng/L (N-nitrosoanatabine (NAT) and NNN), with acceptable accuracy (100 % ± 20 %) and precision (± 15 %). Analyte loss during filtration was < 15 %, and the relative matrix effect was < 10 %. The method was applied to 43 pooled wastewater samples collected from three wastewater treatment plants in Australia between 2017 and 2021. Anabasine and anatabine were detected in all samples at concentrations of 5.0 - 33 ng/L and 12 - 41 ng/L, respectively. Three of the five tobacco-specific nitrosamines (NAT, NNN, and (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) (NNAL)) were detected, in < 50 % of the wastewater samples, with concentrations nearly ten times lower than the tobacco alkaloids (< 1.0 - 6.2 ng/L). In-sewer stability of the nitrosamines was also assessed in this study, with four (NAT, NNAL, NNN, and N-nitrosoanabasine (NAB)) being stable (i.e. < 20 % transformation over 12 h in both control reactor (CR) and rising main reactor (RM) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) being moderately stable (< 40 % loss over 12 h in RM). This direct injection method provides a high-throughput approach in simultaneous investigation of tobacco use and assessment of public exposure to tobacco-specific nitrosamines.

The complex effect of dissolved organic carbon on desorption of per- and poly-fluoroalkyl substances from soil under alkaline conditions.

Per- and poly-fluoroalkyl substances (PFASs) are contaminants of emerging concern, yet the understanding of factors that control their leaching and release from contaminated soils remains limited. This study aimed to investigate the impact of dissolved organic carbon (DOC) on the release of PFASs-specifically, perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA)from soils contaminated by aqueous film forming foam (AFFF). Batch aqueous leaching experiments were conducted on AFFF-contaminated soils under alkaline solution conditions (pH 9.5, 10.5, and 12) as it enhances leaching of both PFAS and DOC. Leaching of PFOS was significantly increased under alkaline conditions. Although the leaching of PFAS generally increased with pH, PFOS appeared to be more retained under the very alkaline pH conditions used in this study. At the same solution pH, leaching of PFOS and DOC was less in Ca(OH)2 than in NaOH. The retention of PFOS under these conditions may be attributable to the shielding of the negative charge of the soil components and colloids (e.g., DOC and clay minerals) in the leachates and/or the screening of negative charges on head groups of PFOS due to the high concentration of divalent cations. Solution chemistry affected desorption of PFOS more than PFHxS and PFOA. The study highlights that the influence of DOC on PFAS leaching and transport can be very complex, and depends on leachate chemistry (e.g., pH and cation type), PFAS chemistry, the magnitude of PFAS contamination and factors that influence the solid:liquid partitioning of organic carbon in soil.

Seven-years of alcohol consumption in Australia by wastewater analysis: Exploring patterns by remoteness and socioeconomic factors.

BACKGROUND: Wastewater analysis provides a complementary measure of alcohol use in whole communities. We assessed absolute differences and temporal trends in alcohol consumption by degree of remoteness and socioeconomics indicators in Australia from 2016 to 2023. METHODS: Alcohol consumption estimates from 50 wastewater treatment plants (WWTP) in the Australian National Wastewater Drug Monitoring Program were used. Trends were analysed based on 1) site remoteness: Major Cities, Inner Regional and a combined remoteness category of Outer Regional and Remote, and 2) using two socioeconomic indexes from the Australian Bureau of Statistics (ABS) relating to advantage and disadvantage for Income, education, occupation, and housing. RESULTS: Consumption estimates were similar for Major Cities and Inner Regional areas (14.3 and 14.4L/day/1000 people), but significantly higher in Outer Regional and Remote sites (18.6L/day/1000 people). Consumption was decreasing in Major cities by 4.5% annually, Inner Regional by 2.4%, and 3.5% in the combined Outer Regional and Remote category. Consumption estimates were higher in socioeconomically advantaged quartiles than those of lower advantage (0%-25% mean = 13.0, 75%-100% mean = 17.4). Consumption in all quartiles decreased significantly over the 7 year period with annual rates of decrease of 0.9%, 3.7%, 3.6%, and 3.0% for the lowest to highest quartile, respectively. CONCLUSIONS: Declines in Australian alcohol consumption have been steeper in large urban areas than regional and remote areas. There were smaller annual decreases in the most socioeconomically disadvantaged areas. If continued, these trends may increase Australian health inequalities. Policy and prevention work should be appropriately targeted to produce more equitable long-term outcomes.

Nationwide occurrence and discharge mass load of per- and polyfluoroalkyl substances in effluent and biosolids: A snapshot from 75 wastewater treatment plants across Australia.

Wastewater treatment plants (WWTPs) have been recognized as secondary sources of per- and polyfluoroalkyl substances (PFAS) released into the environment. In this study, PFAS concentrations were measured in effluent and biosolids samples collected from 75 WWTPs across Australia during the 2016 Census period, which covers more than half of the Australian population. Twelve PFAS compounds, including six C5-C10 perfluoroalkyl carboxylic acids (PFCAs), four perfluoro sulfonic acids (PFSAs) such as perfluorobutane sulfonate (PFBS), perfuorohexane sulfonic (PFHxS), perfluorooctane sulfonic acid (PFOS), and perfluorodecane sulfonic acid (PFDS), and one fluorotelomer sulfonic acid (6:2 FTS), were detected in the effluent, with concentrations up to 504 ng/L (PFHxS). Among these, perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and perfluoropentanic acid (PFPeA) exhibited the highest median concentrations. In the biosolids, a total of 21 PFAS compounds were detected, encompassing ten C4-C14 PFCAs, four PFSAs, two FTS (6:2 and 8:2 FTS), perfluorooctane sulfonamide (PFOSA), two perfluorooctane sulfonamido acetic acid (NMethyl FOSAA and NEthyl FOSAA), and two perfluorooctane sulfonamido ethanol (FOSE), with dry weight (dw) concentrations approaching 235 ng/g (PFOS). The highest median and mean concentrations were observed for perfluorodecanoic acid (PFDA) and PFOS. An annual discharge of approximately 250 kg of the total 21 PFAS compounds was estimated through the effluent and biosolids of the participating WWTPs. Notably, PFOS and 6:2 FTS constituted the largest proportion of total PFAS in the WWTPs' output. While PFCAs were higher in effluent concentrations compared to influent levels across most WWTPs (92% of WWTPs for ∑8PFCAs), the concentrations of PFSAs either decreased or remained relatively stable (in 80% of WWTPs for ∑4PFSAs) throughout the wastewater treatment process.

Wastewater-based monitoring of the nitazene analogues: First detection of protonitazene in wastewater.

Synthetic opioids, particularly the nitazene analogues class, have become a public health concern due to their high potency. Wastewater-based epidemiology can detect community use of these compounds. The objective of this work was to detect nitazene analogues in wastewater from samples collected from eight sites in the United States. Influent wastewater samples were collected from eight sites in seven states (Arizona, Oregon, New Mexico, Illinois, New Jersey, Washington and Georgia) in the United States. Samples were collected from each site on three days between 27 December 2022 and 4 January 2023, acidified on collection, stored frozen and shipped to Arizona State University (Tempe, AZ) for sample processing. Samples were then shipped to The University of Queensland (Brisbane, Australia) for sample analysis. Protonitazene was found in samples collected from two sites in Washington and Illinois. The concentration was estimated up to 0.5 ng/L, with estimated excreted mass loads up to 0.3 mg/day/1000 people. This work has shown that it is possible to detect nitazene analogues in wastewater using a combination of sample pre-concentration and sensitive instrumentation, thereby further expanding the utility of wastewater-based epidemiology.

Blueprint for the design, construction, and validation of a plastic and phthalate-minimised laboratory.

Micro and nanosized plastics (MNPs), and a range of associated additive chemicals, have become pervasive contaminants that humans and the environment are exposed to everyday. However, one of the principal challenges in their analysis is adequate strategies to minimise background contamination. Here a blueprint for a specialised plastics and additive-minimised clean room laboratory built for this purpose is presented. Common laboratory construction materials (n = 23) were tested, including acoustic baffles, ceiling materials, floor materials, glazing rubber, and silicone sealant. The % polymer content ranged from 2-76% w/w while the sum concentration of six phthalates ranged from 0.81 (0.73-0.86) to 21000 (15000-27000) mg/kg, assigning many of these materials as inappropriate for use in a clean room environment. The final design of the laboratory consisted of three interconnected rooms, operated under positive pressure with the inner rooms constructed almost entirely of stainless steel. Background concentrations of MNPs and phthalates in the new laboratory were compared to two Physical Containment Level 2 (PC2) laboratory environments, with concentrations of MNPs reduced by > 100 times and phthalates reduced by up to 120 times. This study reports the first known clean room of its kind and provides a blueprint for reference and use by future plastics research.

Distribution and release of PFAS from AFFF-impacted asphalt: How does it compare to concrete?

Aqueous film forming foam (AFFF)-impacted asphalt and concrete may serve as potential secondary sources of per- and polyfluoroalkyl substances (PFAS) to the environment through surficial leaching. We aimed to understand the vertical distribution and surficial release of PFAS from AFFF-impacted asphalt and concrete cores collected from various locations (∼10-70 m distance between samples). Among the PFAS analyzed, 6:2 FTS was observed as having the highest concentration in the surface layer (0 - 0.5 cm) of concrete (225 µg kg-1) and in the runoff from the concrete (2600 ng L-1). PFOS was detected at the highest concentration in the surface layer (0 - 0.5 cm) of asphalt (47 µg kg-1) and associated runoff (780 ng L-1). The total mass of PFAS released during three rainfall simulations accounts for a fraction of the total mass in the surface layer (0 - 0.5 cm), ranging from 0.10 - 9.8% and 0.078 - 2.4% for asphalt and concrete cores, respectively. Asphalt exhibited a higher release rate than concrete, demonstrated by the higher total release coefficient of PFAS (4 - 16 m-2) compared to that of concrete cores (1 - 5 m-2). These results suggested that, similar to concrete, AFFF-impacted asphalt may be a secondary source of PFAS to the environment.

New PFASs Identified in AFFF Impacted Groundwater by Passive Sampling and Nontarget Analysis.

Monitoring contamination from per- and polyfluoroalkyl substances (PFASs) in water systems impacted by aqueous film-forming foams (AFFFs) typically addresses a few known PFAS groups. Given the diversity of PFASs present in AFFFs, current analytical approaches do not comprehensively address the range of PFASs present in these systems. A suspect-screening and nontarget analysis (NTA) approach was developed and applied to identify novel PFASs in groundwater samples contaminated from historic AFFF use. A total of 88 PFASs were identified in both passive samplers and grab samples, and these were dominated by sulfonate derivatives and sulfonamide-derived precursors. Several ultrashort-chain (USC) PFASs (≤C3) were detected, 11 reported for the first time in Australian groundwater. Several transformation products were identified, including perfluoroalkane sulfonamides (FASAs) and perfluoroalkane sulfinates (PFASis). Two new PFASs were reported (((perfluorohexyl)sulfonyl)sulfamic acid; m/z 477.9068 and (E)-1,1,2,2,3,3,4,5,6,7,8,8,8-tridecafluorooct-6-ene-1-sulfonic acid; m/z 424.9482). This study highlights that several PFASs are overlooked using standard target analysis, and therefore, the potential risk from all PFASs present is likely to be underestimated.

In-sewer stability of 31 human health biomarkers and suitability for wastewater-based epidemiology.

Monitoring urinary markers of dietary, disease, and stress by wastewater-based epidemiology (WBE) is a promising tool to better understand population health and wellbeing. However, common urinary biomarkers are subject to degradation in sewer systems and their fates have to be assessed before they can be used in WBE. This study investigated the stability of 31 urinary biomarkers (12 food biomarkers, 8 vitamins, 9 oxidative stress biomarkers, and 1 histamine biomarker) in a laboratory sewer sediment reactor and evaluated their suitability for WBE, considering their detectability in real wastewater and in-sewer stability. These biomarkers showed various transformation patterns, among which 16 compounds had half-lives <2 h while other 15 compounds presented moderate to high stability (2 to >500 h). Thirteen biomarkers showed potential for WBE because of their consistently measurable concentrations in untreated wastewater and sufficient in-sewer stability. Eighteen biomarkers were unsuitable due to their rapid in-sewer degradation and/or undetectable concentration levels in untreated wastewater using previous methods. Transformation rates of these biomarkers showed generally weak relationships with molecular properties but relatively higher correlations with biological activities in sewers. Overall, this study determined in-sewer stability of 31 health-related biomarkers through laboratory experiments, providing new findings to WBE for population health assessment.

Analysis of wastewater from 2013 to 2021 detected a recent increase in nicotine use in Queensland, Australia.

Previous wastewater-based epidemiology (WBE) studies have reported decreasing trends of nicotine and tobacco use in Australia before 2017, but there is concern that increasing illicit use of nicotine in vaping products and illicit tobacco could reverse this progress. This study aimed to assess temporal trends of nicotine consumption and specifically tobacco consumption via wastewater analysis in a population in Australia between 2013 and 2021. One week of daily wastewater samples were analyzed every two months from February 2013 to December 2021 in a regional city serving ∼100,000 people. A total of 340 daily samples were analyzed for anabasine (tobacco specific biomarker) and nicotine metabolites, cotinine and hydroxycotinine, using direct injection method by liquid chromatography with tandem mass spectrometry. Daily consumption estimates were calculated from daily flow data, population estimates and previously reported excretion factors. Linear spline regression was performed to identify periods when significant change of slopes occurred and to evaluate the temporal trends. Tobacco use monitored using anabasine as a biomarker, showed a decreasing trend over the whole period with a higher rate of decrease during the first two years (2013-2014, 21 % decrease) compared to the later 7 years (2015-2021, 10 % decrease). Nicotine use, monitored using cotinine and hydroxycotinine, showed a downward trend between 2013 and 2018 (2013-2014: 18 % decrease, p < 0.05; 2015-2016: 6 % increase, p = 0.48; Feb-Dec 2017: 15 % decrease, p = 0.39) followed by a significant increase from 2018 to 2021 (40 % increase, p < 0.001). This finding suggests the increasing use of non-tobacco nicotine-based products. Additionally, the tobacco use estimate by wastewater analysis was higher than the tobacco sales data, which suggests the use of illicit tobacco in the catchment.

Calibration and Application of PUF Disk Passive Air Samplers To Assess Chlorinated Paraffins in Ambient Air in Australia, China, and Vietnam.

Ambient air samples were collected in Brisbane (Australia), Dalian (China), and Hanoi (Vietnam) during Mar 2013-Feb 2018 using polyurethane foam based passive air samplers. A sampling rate calibration experiment was conducted for chlorinated paraffins (CPs, i.e., short-chain, medium-chain, and long-chain CPs), where the sampling rates were 4.5 ± 0.7, 4.8 ± 0.3, and 4.8 ± 2.1 m3 day-1 for SCCPs, MCCPs, and LCCPs, respectively. The atmospheric concentration of CPs was then calculated and the medians of ∑CPs were 0.079, 1.0, and 0.89 ng m-3 in Brisbane, Dalian, and Hanoi, respectively. The concentration of CPs in Brisbane's air remained at low levels, with no significant differences observed between the city background site and the city center site, indicating limited usage and production of CPs in this city. The highest concentration of MCCPs was detected in Dalian, while the highest concentration of SCCPs was detected in Hanoi. A decrease of SCCP concentration and an increase of MCCPs' were found in Brisbane's air from 2016 to 2018, while increasing trends for both SCCPs and MCCPs were observed in Dalian. These results indicated impacts from different sources of CPs in the investigated cities.

Bisphenols and phthalates in Australian wastewater: A statistical approach for estimating contributions from diffuse and point sources.

Chemicals associated with plastics, such as bisphenols and phthalates, enter sewerage from both diffuse (domestic/commercial) and point (industrial) sources. In this study, we aimed to devise a conservative, statistical baseline to estimate contributions from these source types when sampling of specific sources is not possible. Population-normalised mass loads of two bisphenols and nine phthalates were estimated in wastewater samples from 22 sewage treatment plants (STPs) in 2019. Two multiday (10 and 7 day) pools were created for each STP. Baseline (diffuse) release thresholds were set at the mean of the first quartile (Q1) plus 10 times the standard deviation (STDV) of this quartile [Q1 mean + (10 x STDV)], with contributions over this considered to come from point sources. Chemicals with at least one population-normalised mass load more than three times their baseline were classified as point-source dominant and the remaining as diffuse-source dominant. Eleven of the twelve chemicals examined were detected above limits of quantification in all wastewater samples. Bisphenol A (BPA), bisphenol S (BPS), di-isononyl phthalate (DiNP) and di-methyl phthalate (DMP) were classified as point-source dominant chemicals. The total annual mass loads entering STPs across Australia were estimated to be 4.2 tonnes/year from diffuse sources and 4.5 tonnes/year from point sources for bisphenols, and 47 tonnes/year from diffuse sources and 5.9 tonnes/year from point sources for phthalates.

Spatial and temporal trends of 64 pesticides and their removal from Australian wastewater.

Pesticides are necessary for the control of pest plant, fungi and insect species. After application, they may find their way into waste streams, such as municipal sewage, where their spatio-temporal distribution has not been well characterised. To further understand the spatio-temporal distribution and to evaluate potential sources and fate after treatment, 64 pesticides were analysed in matched influents and effluents of 22 wastewater treatment plants (WWTPs) from across Australia. The pesticides consisted of 30 herbicides and 8 herbicide metabolites or transformation products, 16 insecticides and 10 fungicides. The samples were 1084 24-hr composite samples pooled into 113 samples. Pools represented two influent and one effluent pools at each of 22 sites in 2019, as well as two pools per year from 2009 to 2021 for an 11-year long-term temporal trend at a subset of two locations. The total population served by the 22 sites was equivalent to ~41 % of the Australian population. Of the 64 pesticides, 25 were detected in influent, with highest influent concentrations up to 100 µg/L and effluent concentrations up to 16 µg/L for the herbicide 2,4-D. The total mass of pesticides was extrapolated to Australia, suggesting ~33 t of the targeted pesticides entered WWTP influent annually nation-wide, with 14 t emitted into effluents annually. Long-term trends varied by analyte and for carbendazim decreases over time, may be related to restrictions in use. Risk quotients (RQs) were calculated for 14 analytes in the effluent. 35 % had an RQ above one, indicating a potential environmental risk. Fipronil had the highest RQ (49) at Site 6. The population-normalized mass loads of pesticides were site-specific, and in some cases correlated with land use attributes suggestive of point sources. This reflects a need to better characterise sources to enable prevention, or possible pre-treatment of pesticide-containing wastewater entering municipal sewage streams.

Evaluation of sealants to mitigate the release of per- and polyfluoroalkyl substances (PFAS) from AFFF-impacted concrete: Characterization and forecasting.

Per- and polyfluoroalkyl substances (PFAS) within concrete pads impacted by historical firefighting training using aqueous film-forming foam (AFFF) may be potential secondary sources of PFAS due to surficial leaching. This study aimed to (i) characterize the effectiveness of two commercially available sealants (Product A and Product B) in mitigating leaching of five PFAS (e.g., PFOS, PFOA, PFHxS, PFHxA, 6:2 FTS) from concrete surfaces at the laboratory-scale, and (ii) develop a model to forecast cumulative leaching of the same five PFAS over 20 years from sealed and unsealed concrete surfaces. Laboratory trials demonstrated that both sealants reduced the surficial leaching of the five PFAS studied, and Product B demonstrated a comparatively greater reduction in surface leaching than Product A as measured against unsealed controls. The cumulative PFOS leaching from an unsealed concrete surface is estimated by the model to be about 400 mg/m2 over 20 years and reached asymptotic conditions after 15 years. In contrast, the model output suggests asymptotic conditions were not achieved within the modeled time of 20 years after sealing with Product A and 85% of PFOS was predicted to have leached (∼340 mg/m2). Negligible leaching of PFOS after sealing with Product B was observed ( < 5 × 10-9 mg/m2). Results from modeled rainfall scenarios suggest PFAS leachability is reduced from sealed versus unsealed AFFF-impacted concrete surfaces.

Novel Per- and Polyfluoroalkyl Substances Discovered in Cattle Exposed to AFFF-Impacted Groundwater.

The leaching of per- and polyfluoroalkyl substances (PFASs) from Australian firefighting training grounds has resulted in extensive contamination of groundwater and nearby farmlands. Humans, farm animals, and wildlife in these areas may have been exposed to complex mixtures of PFASs from aqueous film-forming foams (AFFFs). This study aimed to identify PFAS classes in pooled whole blood (n = 4) and serum (n = 4) from cattle exposed to AFFF-impacted groundwater and potentially discover new PFASs in blood. Thirty PFASs were identified at various levels of confidence (levels 1a-5a), including three novel compounds: (i) perfluorohexanesulfonamido 2-hydroxypropanoic acid (FHxSA-HOPrA), (ii) methyl((perfluorohexyl)sulfonyl)sulfuramidous acid, and (iii) methyl((perfluorooctyl)sulfonyl)sulfuramidous acid, belonging to two different classes. Biotransformation intermediate, perfluorohexanesulfonamido propanoic acid (FHxSA-PrA), hitherto unreported in biological samples, was detected in both whole blood and serum. Furthermore, perfluoroalkyl sulfonamides, including perfluoropropane sulfonamide (FPrSA), perfluorobutane sulfonamide (FBSA), and perfluorohexane sulfonamide (FHxSA) were predominantly detected in whole blood, suggesting that these accumulate in the cell fraction of blood. The suspect screening revealed several fluoroalkyl chain-substituted PFAS. The results suggest that targeting only the major PFASs in the plasma or serum of AFFF-exposed mammals likely underestimates the toxicological risks associated with exposure. Future studies of AFFF-exposed populations should include whole-blood analysis with high-resolution mass spectrometry to understand the true extent of PFAS exposure.

Monitoring medication and illicit drug consumption in a prison by wastewater-based epidemiology: Impact of COVID-19 restrictions.

Drug consumption in prisons is a concern for the safety of incarcerated people and staff. Typically, drug use prevalence in prisons is estimated through urinalysis and intelligence operations, which can be intrusive and stressful. An alternative approach, wastewater-based epidemiology (WBE), was used in this study to estimate the consumption of licit and illicit drugs for the entire population of a prison in Australia. Wastewater samples were collected from March to December 2020, covering periods of no restrictions and periods when prison access was restricted to prevent the transmission of COVID-19. Target biomarkers were analysed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The average consumption of common illicit drugs (MDMA, methamphetamine and cocaine) over the sampling period in the prison (0.5 - 4.5 mg/1000 people/day) was two to three orders of magnitude lower than in the community population (254 - 1000 mg/1000 people/day). Comparison of WBE estimates against pharmacy dispensing data suggested potential illicit buprenorphine consumption at the prison. Methamphetamine and buprenorphine use decreased when no visitors were allowed (18% - 72% decrease for methamphetamine; about half decrease for buprenorphine) and increased once these restrictions were eased (22% - 39% increase for methamphetamine; 44% - 67% increase for buprenorphine). The changes in drug use may be attributed in part to a reduction of drug trafficking into the prison from visitors or non-essential staffs and in part to the reduced contribution of urine from staff who used toilets within the prison. This study provided useful information on the scale of illicit drug use and extra-medical use of licit drugs in prison, and its changes under different security conditions.

Exploring drug consumption patterns across varying levels of remoteness in Australia.

Wastewater-based epidemiology (WBE) relies on representative sampling that is typically achieved with autosamplers that collect time, flow, or volume proportional samples. The expense, resources and operational know-how associated with autosampler operation means they are only typically available at major wastewater treatment plants (WWTPs). This results in a lack of data on consumption levels in regional and remote areas, or in countries that lack the financial means. The aim of this study was to estimate and investigate trends in drug consumption across varying levels of remoteness in Australia. Field-calibrated, microporous polyethylene passive samplers were deployed over 2 periods (Aug/Sept 2019 and 2020) at 43 treatment plants covering all five categories of remoteness, as per Australian Bureau of Statistics definitions (Major cities, Inner regional, Outer regional, Remote, and Very remote). The per capita consumption of cocaine, methylamphetamine, nicotine, oxycodone and MDMA were estimated. No spatial trends between remoteness and drug consumption were observed, except for cocaine, where Major cities had a 5-to-10-fold higher consumption compared to the other levels of remoteness in 2019 and 2020, respectively. Outer regional sites had the highest and lowest methylamphetamine consumption. The variance in drug use among sites was much higher in Remote (and Inner/Outer regional) sites when compared with Major cities. A significant and consistent decrease in oxycodone consumption was observed at all sites between 2019 and 2020, possibly related to regulatory changes and the COVID-19 pandemic where elective surgeries were suspended. The majority of sites experienced a decrease in cocaine and methylamphetamine consumption, possibly due to border restrictions or changes in supply and demand dynamics. This was the first extensive passive sampling study to assess drug consumption in urban, regional, and remote locations, demonstrating that passive samplers can facilitate extension of wastewater-based drug monitoring programs to sites where other representative sampling options are very difficult to implement.

Evaluation and identification of chemical migrants leached from baby food pouch packaging.

Multilayer plastic pouch (MLPP) has an estimated 9% annual increase of market growth. However, the migrants it can introduce to food has not yet been systematically studied. A total of 79 MLPPs for baby food were purchased from major retail outlets in Australia. The methodology for testing chemical migration followed the design of previous studies using four types of selected simulants according to the European Committee Regulation No. 10/2011 method. Four bisphenols and five phthalic acid diesters (PAEs) were detected, including the ones known for endocrine disrupting effect in human. Three intentionally added and 23 non-intentionally added substances (NIAS) were tentatively identified through a suspect screening procedure. Out of the 23 NIAS, neopentyl glycol - phthalic acid - 1,6-hexanediol - phthalic acid oligomer was identified for the first time with MLPP. A further two NIAS were detected for the first time in baby food related products. For 40% of the pouches where adipic acid - diethylene glycol was detected, the estimated exposure from consuming one pouch of food per day may exceed the threshold of toxicological concern established based on the Cramer classification.

Direct injection liquid chromatography-tandem mass spectrometry as a sensitive and high-throughput method for the quantitative surveillance of antimicrobials in wastewater.

Environmental antimicrobial pollution and antimicrobial resistance pose a threat to environmental and human health. Wastewater analysis has been identified as a promising tool for antimicrobial monitoring and the back-estimation of antimicrobial consumption, but current pretreatment methods are tedious and complicated, limiting their scope for high-throughput analysis. A sensitive direct injection method for the quantification of 109 antimicrobials and their metabolites in wastewater samples was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated for both wastewater influent and effluent in terms of specificity, calibration range, matrix effect, filtration loss, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Most analytes achieved calibration of R2 > 0.99, and the calibration range was from 0.0002 to 150 µg L-1. Recoveries ranged consistently between ~50 % and ~100 % and losses were attributed to sample filtration. Method LOQs were determined as low as 0.0003 µg L-1, and acceptable accuracy (75 %-125 %) and precision (within 25 %) were achieved for >90 % of the analytes. The method was subsequently further assessed using wastewater of raw influent and treated effluent collected from 6 Australian wastewater treatment plants in 2021. In total, 37 analytes were detected in influent and 22 in effluent. Most of them could be quantified at concentrations ranging from 0.0053 to 160 µg L-1, with benzalkonium chloride-C12, amoxicilloic acid, and cephalexin detected at the highest concentrations. The current study provides a straightforward analytical method for antimicrobial monitoring in wastewater with a fast and simple pretreatment procedure.