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.

Indoor air pollution is associated with respiratory symptoms in children in urban Vietnam.

Exposure to indoor air pollution (IAP) is a leading environmental risk for respiratory diseases. We investigated the relationship between respiratory symptoms and polluting indoor activities such as smoking, cooking and contact with pets among children in Ho Chi Minh City (HCMC), Vietnam. A cross-sectional survey applied a multistage sampling method in 24 randomly selected secondary schools across the city. Approximately 15,000 students completed self-administrated questionnaires on risk factors and respiratory health outcomes within the preceding 12 months. Data were analyzed using a multivariable logistic regression model with robust standard errors. Wheeze was the most common respiratory symptom (39.5 %) reported, followed by sneezing and runny nose (28.3 %). A small percentage of students self-reported asthma (8.6 %). Approximately 56 % of participants lived with family members who smoked. A positive association between exposure to indoor secondhand smoke and respiratory symptoms was observed, with adjusted odds ratios (aOR) of 1.41 (95 % CI: 1.25-1.60, p < 0.001) for wheezing and 1.64 (95 % CI: 1.43-1.87, p < 0.001) for sneezing and runny nose, respectively. Using an open stove fuelled by coal, wood, or kerosene for cooking was associated with wheeze (aOR: 1.36, CI 95 %: 1.10-1.68, p = 0.01) and sneezing and runny nose (aOR: 1.36, CI 95 %: 1.09-1.69, p = 0.01). In the present study, IAP was associated with adverse health outcomes, as evidenced by an increase in respiratory symptoms reported within the previous 12 months.

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.

Predicting the long-term effects of electronic cigarette use on population health: a systematic review of modelling studies.

OBJECTIVE: To systematically review and synthesise the findings of modelling studies on the population impacts of e-cigarette use and to identify potential gaps requiring future investigation. DATA SOURCE AND STUDY SELECTION: Four databases were searched for modelling studies of e-cigarette use on population health published between 2010 and 2023. A total of 32 studies were included. DATA EXTRACTION: Data on study characteristics, model attributes and estimates of population impacts including health outcomes and smoking prevalence were extracted from each article. The findings were synthesised narratively. DATA SYNTHESIS: The introduction of e-cigarettes was predicted to lead to decreased smoking-related mortality, increased quality-adjusted life-years and reduced health system costs in 29 studies. Seventeen studies predicted a lower prevalence of cigarette smoking. Models that predicted negative population impacts assumed very high e-cigarette initiation rates among non-smokers and that e-cigarette use would discourage smoking cessation by a large margin. The majority of the studies were based on US population data and few studies included factors other than smoking status, such as jurisdictional tobacco control policies or social influence. CONCLUSIONS: A population increase in e-cigarette use may result in lower smoking prevalence and reduced burden of disease in the long run, especially if their use can be restricted to assisting smoking cessation. Given the assumption-dependent nature of modelling outcomes, future modelling studies should consider incorporating different policy options in their projection exercises, using shorter time horizons and expanding their modelling to low-income and middle-income countries where smoking rates remain relatively high.

Improving Wastewater-Based Tobacco Use Estimates Using Anabasine.

In wastewater-based epidemiology (WBE), nicotine metabolites have been used as biomarkers for monitoring tobacco use. Recently, the minor tobacco alkaloids anabasine and anatabine have been suggested as more specific biomarkers for tobacco use since nicotine use can be from both tobacco and non-tobacco sources. This study aimed to provide an in-depth evaluation of the suitability of anabasine and anatabine as WBE biomarkers of tobacco and subsequently estimate their excretion factors for WBE applications. Pooled urine (n = 64) and wastewater samples (n = 277), collected between 2009 and 2019 in Queensland, Australia, were analyzed for nicotine and its metabolites (cotinine and hydroxycotinine), as well as anabasine and anatabine. Anabasine performed as the better biomarker, showing a similar per capita load in pooled urine (2.2 ± 0.3 µg/day/person) and wastewater samples (2.3 ± 0.3 µg/day/person), while the per capita load of anatabine in wastewater was 50% higher than its load in urine. It is estimated that 0.9 µg of anabasine was excreted per cigarette smoked. Triangulation of tobacco sales data and tobacco use estimated from either anabasine or cotinine showed that anabasine-based estimates were 5% higher than sales data, while cotinine-based estimates were between 2 and 28% higher. Our results provided concrete evidence to confirm the suitability of anabasine as a specific biomarker for monitoring tobacco use by WBE.

Increased Nicotine Consumption in Australia During the First Months of the COVID-19 Pandemic.

INTRODUCTION: Mixed findings have been reported about the impact of the COVID-19 pandemic on smoking behavior in different populations. AIMS AND METHODS: In this study, we aimed to quantify changes in smoking prevalence through the proxy of nicotine consumption in the Australian population from 2017 to 2020 inclusive. Estimates of nicotine consumption between 2017 and 2020 were retrieved from a national wastewater monitoring program that covers up to 50% of the Australian population. National sales data for nicotine replacement therapy (NRT) products from 2017 to 2020 were also acquired. Linear regression and pairwise comparison were conducted to identify data trends and to test differences between time periods. RESULTS: The average consumption of nicotine in Australia decreased between 2017 and 2019 but increased in 2020. Estimated consumption in the first half of 2020 was significantly higher (~30%) than the previous period. Sales of NRT products increased gradually from 2017 to 2020 although sales in the first half of the year were consistently lower than in the second half. CONCLUSION: Total nicotine consumption increased in Australia during the early stage of the pandemic in 2020. Increased nicotine consumption may be due to people managing higher stress levels, such as from loneliness due to control measures, and also greater opportunities to smoke/vape while working from home and during lockdowns in the early stage of the pandemic. IMPLICATIONS: Tobacco and nicotine consumption have been decreasing in Australia but the COVID-19 pandemic may have temporarily disrupted this trend. In 2020, the higher impacts of lockdowns and working from home arrangements may have led to a temporary reversal of the previous downward trend in smoking during the early stage of the pandemic.

Assessing changes in nicotine consumption over two years in a population of Hanoi by wastewater analysis with benchmarking biomarkers.

Monitoring the actual change in consumption of nicotine (a proxy for smoking) in the population is essential for formulating tobacco control policies. In recent years, wastewater-based epidemiology (WBE) has been applied as an alternative method to estimate changes in consumption of tobacco and other substances in different communities around the world, with high potential to be used in resource-scarce settings. This study aimed to conduct a WBE analysis in Hanoi, Vietnam, a lower-middle-income-country setting known for high smoking prevalence. Wastewater samples were collected at two sites along a sewage canal in Hanoi during three periods: Period 1 (September 2018), Period 2 (December 2018-January 2019), and Period 3 (December 2019-January 2020). Concentrations of cotinine, 3-hydroxycotinine, and nicotine ranged from 0.73 µg/L to 3.83 µg/L, from 1.09 µg/L to 5.07 µg/L, and from 0.97 µg/L to 9.90 µg/L, respectively. The average mass load of cotinine estimated for our samples was 0.45 ± 0.09 mg/day/person, which corresponds to an estimated daily nicotine consumption of 1.28 ± 0.25 mg/day/person. No weekly trend was detected over the three monitoring periods. We found the amount of nicotine consumption in Period 1 to be significantly lower than in Period 2 and Period 3. Our WBE estimates of smoking prevalence were slightly lower than the survey data. The analysis of benchmarking biomarkers confirmed that cotinine was stable in the samples similar to acesulfame, while paracetamol degraded along the sewer canal. Further refinement of the WBE approach may be required to improve the accuracy of analyzing tobacco consumption in the poor sewage infrastructure setting of Vietnam.

Assessing alcohol consumption in a Chinese urban population and a university town using high temporal resolution wastewater-based epidemiology.

BACKGROUND: Alcohol consumption is a leading preventable risk factor for morbidity and mortality in China. Understanding drinking patterns provides important data to inform public health policies in alcohol control, especially in specific groups like university students. This study aims to assess the alcohol consumption patterns and level of use in an urban population and a university town in a Chinese city using wastewater-based epidemiology (WBE). METHODS: Daily wastewater sample was collected from an urban catchment (n = 270) and every Wednesday's sample from a university town of 10 university campus (n = 43) in 2017-2018. Concentration of alcohol consumption biomarker in wastewater, ethyl sulfate, was measured by direct injection LC-MS/MS analysis. Per capita daily alcohol consumption was then back calculated for assessment purposes. RESULTS: Per capita daily alcohol consumption was 1.4 ± 0.6 mL/ person aged 15 + /day (EPD) (range: 0.2-4.9) in the urban catchment and 1.3 ± 0.6 EPD (range: 0.3-2.6) in the university town. Trends of alcohol consumption were stable in both catchments in 2017-2018. Alcohol consumption on weekends (1.5 EPD) and weekdays (1.4 EPD) were at a similar level. Additionally, no difference was observed between holidays (1.5 EPD) and non-holidays (1.4 EPD). CONCLUSION: There is a stable weekly drinking level in the studied urban population, which is different compared to studies conducted in Western countries. Our study suggested a similar consumption level between the urban population and university students. Drinking during weekdays could negatively affect China's economic productivity and future public health policies could be adapted to reflect this pattern of drinking.

Comparison of tobacco use in a university town and a nearby urban area in China by intensive analysis of wastewater over one year period.

Understanding smoking patterns in the population is essential for formulating public health and tobacco control policies. Wastewater-based epidemiology (WBE) is a valuable complementary approach to conventional survey methods to measure tobacco use, providing non-invasive information in an objective and cost-effective manner. This study estimates tobacco use in an urban population at daily resolution and in a university town at weekly resolution in China. Wastewater samples were collected daily in an urban catchment (n = 279) and every week from a university town located within 13 km of the urban catchment (n = 43) in 2017-2018. The tobacco-related biomarkers, cotinine and hydroxycotinine, and nicotine were analyzed via direct injection liquid chromatography tandem mass spectrometry (LC-MS/MS). Per capita daily tobacco use was back-estimated based on cotinine in wastewater. Over the year of sampling, we observed an increasing trend in tobacco use in the urban catchment that corroborated with sales statistics in 2017-2018. Tobacco use in the urban area was estimated to be 1.16 cigarettes/person aged 15+/day, while it was estimated to be 0.60 cigarettes/person aged 15+/day in the university town. The level of tobacco use in the university town remained stable over the year in contrast to the urban area. The difference of tobacco use in the two catchments may be attributed to their demographic differences. Furthermore, the Tobacco-Free Campus Policy would be a possible reason for the lower level of tobacco use in the university town.

Estimating population-level of alcohol, tobacco and morphine use in a small Russian region using wastewater-based epidemiology.

INTRODUCTION: Alcohol, tobacco and illicit drug use combined are the largest modifiable health risk factors. Wastewater-based epidemiology (WBE) is a complementary approach for monitoring substance use in the population. In this study we applied WBE technique to a community in the Moscow region to estimate population-level consumption of alcohol, tobacco and morphine. METHODS: Wastewater sampling was carried out over 47 days, in 2018 and 2019, including the New Year period. Analysis of the samples for consumption biomarkers (ethyl sulphate, cotinine and morphine) were undertaken using liquid chromatography tandem mass spectrometry (LC-MS/MS). Daily consumption estimates were then compared with sales/production/prescription data and between different days of the week using Mann-Whitney U test. RESULTS: Alcohol consumption was significantly higher on Sundays and during the New Year and Russian Christmas period compared to weekdays and Saturdays. Tobacco consumption estimates were largely consistent throughout the week. Morphine was detected by WBE during the monitoring period but was inconsistent with prescription record data. DISCUSSION AND CONCLUSIONS: This study provides evidence for the feasibility of conducting WBE in Russia. Estimates of alcohol consumption derived from WBE were higher than average alcohol sales data for the country. The estimated consumption of nicotine is generally consistent with the production data, with estimates higher than in most other countries. Our results also suggest potential illegal use of opioids (morphine-based) in the population. Given the considerable health and economic costs of substance use in Russia, more extensive WBE testing is recommended to inform and evaluate public health policies.

Secondhand smoke in public places in Vietnam: An assessment 5 years after implementation of the tobacco control law.

OBJECTIVES: This study quantified the secondhand smoke (SHS) concentration in a sample of public places in Vietnam to determine changes in SHS levels 5 years after a public smoking ban was implemented. METHODS: Two monitoring campaigns, one in 2013 (before the tobacco control law was implemented) and another in 2018 (5 years after the implementation of the law) were conducted in around 30 restaurants, cafeterias and coffee shops in major cities of Vietnam. Concentrations of PM2.5, as an indicator of SHS, were measured by portable particulate matter monitors (TSI SidePak AM510 and Air Visual Pro). RESULTS: The geometric mean PM2.5 concentration of all monitored venues was 87.7 µg/m3 (83.7-91.9) in the first campaign and 55.2 µg/m3 (53.7-56.7) in the second campaign. Pairwise comparison showed the PM2.5 concentrations in the smoking observed area was triple and double those in the non-smoking area and the outdoor environment. After adjusting for sampling locations and times, the SHS concentration 5 years after the implementation of the tobacco control law reduced roughly 45%. CONCLUSION: The study results indicate an improvement in air quality in public places in Vietnam via both the reduction in PM2.5 levels and the number of people observed smoking. However, greater enforcement of the free-smoke legislation is needed to eliminate SHS in public places in Vietnam.

Long-term trends in tobacco use assessed by wastewater-based epidemiology and its relationship with consumption of nicotine containing products.

Measurement of population tobacco use via wastewater-based epidemiology (WBE) provides objective data to evaluate the efficacy of tobacco control strategies. However, current WBE tobacco-use estimates based on nicotine metabolites (cotinine and hydroxycotinine) can be masked by use of non-tobacco nicotine-containing products. To better understand nicotine and tobacco use, we analysed tobacco-specific biomarkers, anabasine and anatabine, as well as nicotine metabolites, cotinine and hydroxycotinine, in wastewater samples collected for 6 weeks per year over 6 years (2012-2017) from an Australian wastewater treatment plant serving approximately 100,000 people. Population-normalised mass loads were used to estimate tobacco and nicotine use trends and were compared with surveys and taxation statistics. Significant annual declines were observed for anabasine, anatabine, cotinine and hydroxycotinine of -3.0%, -2.7%, -2.4%, and -2.1%, respectively. The results corresponded with the annual declining trends reported from surveys (-5%) and taxation statistics (-4%). Significant annual decreases in the ratios of anabasine to cotinine (-1.2%) and anatabine to cotinine (-1.0%) suggested a relative increase in the use of non-tobacco nicotine products at the same time that tobacco use was declining. Monitoring tobacco use with anabasine and anatabine removed influence from nicotine-containing products, showing larger reductions in this Australian city than via nicotine biomarkers, whilst also demonstrating their suitability for monitoring long-term trends.

Determination of anabasine, anatabine, and nicotine biomarkers in wastewater by enhanced direct injection LC-MS/MS and evaluation of their in-sewer stability.

Wastewater-based epidemiology (WBE) has been used to estimate tobacco use in the population. However, the increased use of nicotine replacement therapies and e-cigarettes contributes to the load of nicotine metabolites in wastewater, causing over-estimation of tobacco use if nicotine metabolites were used in WBE back-estimation. This study aims to develop a rapid method for determining the tobacco-specific biomarkers, anabasine and anatabine, in wastewater and to evaluate their in-sewer stability for better estimation of tobacco use by WBE. An enhanced direct injection LC-MS/MS was developed to quantify anabasine and anatabine as well as nicotine biomarkers (nicotine, cotinine and hydroxycotinine). The method was optimal when wastewater was filtered through 0.2 µm RC syringe filters and a pre-conditioned SPE cartridge (Oasis HLB 1 cc, 30 mg) before 50 µL was injected into the LC-MS/MS system. Limits of quantification varied between 2.7 and 54.9 ng/L with recoveries from 76% to 103% for all five compounds. In sewer reactors, anabasine and anatabine were less stable than cotinine and hydroxycotinine. They were more stable in the gravity sewer reactor with <20% loss in 12 h than in the rising main sewer reactor with ~30% loss in the same period. We then applied the new method to 42 daily wastewater influent samples collected from an Australian wastewater treatment plant. The five biomarkers were detected in all samples with concentrations ranging from 9.2 to 7430 ng/L. All five compounds were positively correlated with one another. Our results suggested a high throughput analytical method for feasible application in anabasine and anatabine as biomarkers of tobacco use in routine wastewater monitoring.

Using wastewater-based epidemiology to estimate consumption of alcohol and nicotine in major cities of China in 2014 and 2016.

Monitoring the use of alcohol and tobacco in the population is important for public health planning and evaluating the efficacy of intervention strategies. The aim of this study was to use wastewater-based epidemiology (WBE) to estimate alcohol and tobacco consumption in a number of major cities across China and compare WBE estimates with other data sources. Daily composite influent wastewater samples were collected from wastewater treatment plants (WWTPs) across China in 2014 (n = 53) and 2016 (n = 45). The population-normalized daily consumption estimated by WBE were compared with other data sources where available. The average consumption of alcohol was 8.1 ± 7.0 mL ethanol/person aged 15+/day (EPD) in the investigated cities of 2016 while those involved in 2014 had an average consumption of 4.7 ± 3.0 EPD. The average tobacco consumption was estimated to be 3.7 ± 2.2 cigarettes/person aged 15+/day (CPD) in 2016 and 3.1 ± 1.9 CPD in 2014. The changes in the average consumption in those cities from 2014 to 2016 were supported by the results from a limited number of WWTPs where samples were collected in both years. Consumption of alcohol and tobacco in urban China is at a medium level compared with other countries on a per capita basis. WBE estimates of tobacco consumption were relatively comparable with results of traditional surveys and sales statistics. WBE estimates of alcohol consumption were lower than WHO survey results, probably due to EtS degradation and uncertainty in the EtS excretion factor.

Monitoring consumption of methadone and heroin in major Chinese cities by wastewater-based epidemiology.

BACKGROUND: Methadone maintenance treatment (MMT) services have been used in China for treatment of heroin dependence. But no study has been conducted to assess the appropriateness of MMT distribution and the potential abuse of methadone in China. This study aims to do that through a nationwide estimation of methadone consumption in China via wastewater-based epidemiology and subsequently compare it with MMT data and level of heroin abuse. METHODS: Wastewater samples were collected from 53 wastewater treatment plants in 27 major cities that cover all geographic regions of China. Methadone and pure heroin consumptions were estimated based on influent concentrations of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), morphine and codeine. RESULTS: Drug residues were detected in most samples. The ratio of EDDP/methadone was around 2 in influents and methadone and EDDP loads were strongly correlated, indicating that they originated from human consumption. Both influent methadone and EDDP loads in Southwest and Northwest China were significantly higher than those in other regions. The highest estimated consumptions of methadone and heroin in China were 22.0 ±â€¯2.1 mg/1000 in./d and 263.9 ±â€¯115.9 mg/1000 in./d, respectively. There was a significant positive correlation between methadone and heroin consumptions. CONCLUSIONS: Consumption of methadone in China was primarily from MMT services. The use of methadone and heroin displayed a clear geographical pattern: it is higher in the western inland regions than in the eastern regions. This study has shown that the distribution of MMT services is reflective of the level of heroin abuse in different regions of China.

Evaluating the stability of three oxidative stress biomarkers under sewer conditions and potential impact for use in wastewater-based epidemiology.

Wastewater contains a wealth of information about the population who contribute to it including biological and chemical markers of human activity and exposures. F2-isoprostanes have been proposed as oxidative stress biomarkers that can be measured in wastewater to provide a measure of oxidative stress at the population level. While an association between tobacco use and their level in wastewater has been demonstrated, an in-sewer stability assessment has not been conducted to support their use as oxidative stress biomarkers for wastewater-based epidemiology studies. In this study we investigated the stability of 8-iso-prostaglandin F2α (PGF2α), its metabolite dinor-11ß-Prostaglandin F2α (dnPGF2α) and Prostaglandin E2 (PGE2) (representative of other classes of prostaglandins) in laboratory-scale sewer reactors simulating real sewers. PGF2α, dnPGF2α and PGE2 were all found to be sufficiently stable under typical sewer conditions therefore satisfying the stability requirement of wastewater-based epidemiology population health biomarkers.

Polycyclic aromatic hydrocarbons, polychlorinated biphenyls and legacy and current pesticides in indoor environment in Australia - occurrence, sources and exposure risks.

Paired indoor air and floor dust samples were collected from residential houses and offices (n = 28) in two Australian cities in 2015. For the air samples, a modified passive air sampler (PAS) was used to collect semi-volatile organic compounds (SVOCs) in gaseous phase and airborne particles simultaneously. Sampling rates (R) of the PAS for gaseous SVOCs ranged from 0.69 to 3.4 m3 sampler-1 day-1. Out of the 33 analytes, 22, 14 and 17 compounds were detected (above the method detection limit) in over 50% of air, airborne particles and floor dust samples respectively. The highest median level in air, airborne particles and floor dust was observed for phenanthrene (2.0 ng m-3), permethrin (8800 ng g-1) and permethrin (5100 ng g-1) respectively. Among polychlorinated biphenyl (PCB) congeners, with few exceptions, the largest contribution was from 3,3'-dichlorobiphenyl (PCB11) for both indoor air and floor dust samples. In these houses and offices, the indoor level of polycyclic aromatic hydrocarbons (PAHs) was mainly influenced by ambient (outdoor) air. Primary sources of PCBs were from within indoor environments and generally older houses have higher concentrations in air. Among pesticides, hexachlorobenzene in indoor environments appeared to be due to transfer from outdoor sources whereas chlordanes and pyrethroids were associated with past and current household application respectively. Compared to data from other countries/regions, concentrations of chlordanes, chlorpyrifos and pyrethroids in indoor air and dust samples from Australia were among the highest whereas PCB and PAH levels were among the lowest. The sum of estimated daily intakes (EDIs) via inhalation and dust contact and ingestion were calculated. The highest median value of EDI was observed for permethrin at 2.8 (for adults) and 74 ng kg-1 day-1 (for toddlers), which are <0.15% of the U.S. EPA reference dose.

Chlorinated paraffins in indoor dust from Australia: Levels, congener patterns and preliminary assessment of human exposure.

Chlorinated paraffins (CPs) are a group of polychlorinated n-alkanes with high production volumes. Until now, there are only limited data on the levels of CPs in the environment, especially in the indoor environment. In this study, dust samples were collected from 44 indoor environments, including 27 private houses, 10 offices, and 7 vehicles. Short-, medium-, and long-chain CPs were detected in all dust samples. The median concentration of ∑CPs (C10-C21) was 57, 160 and 290 µg/g, in houses, offices, and vehicles, respectively. Medium-chain CPs were the dominant group, on average accounting for 86% of ∑CPs. Cl6 and Cl8 groups had the highest contributions to ∑CPs across all the different microenvironments, while C13 and C14 were the predominant groups of SCCPs and MCCPs. Median exposure to ∑CPs via indoor dust were estimated at 80 ng/kg/day and 620 µg/kg/day for Australian adults and toddlers respectively. The daily intake of CPs via dust, in the worse scenario, was still 2-3 orders of magnitudes lower than the reference doses based on neoplastic effects.

Assessment of drugs and personal care products biomarkers in the influent and effluent of two wastewater treatment plants in Ho Chi Minh City, Vietnam.

Wastewater samples were collected at the influent and effluent of two wastewater treatment plants (WWTPs) in Ho Chi Minh City, Vietnam and then pooled to daily samples over multiple days using 6 hourly grab samples. The aim was to provide a first assessment of the occurrence, consumption, removal and release of a range of organic chemicals including pharmaceuticals and personal care products (PPCPs), illicit drugs, an artificial sweetener, tobacco and its metabolites and alcohol biomarkers (referred to here as DPCPBs). Nineteen DPCPBs were detected via direct measurement of filtered wastewater on LC-MS/MS with a concentration range of 0.05-38µg/L. Caffeine and paracetamol were the most prominent compounds detected in the influent, while acesulfame was found at the highest concentration in the effluent of both WWTPs. Mean concentrations of metabolites of tobacco (nicotine: 7.6µg/L, cotinine: 1.4µg/L and hydroxycotinine: 1.7µg/L) and alcohol (ethyl sulphate: 3.3µg/L) were lower than those of European countries. Consumption rates based on daily mass loads and catchment population data obtained from the WWTPs were <10g/d/1000 pp for the majority of selected PPCPs, except for caffeine (300g/d/1000 pp) and paracetamol (320g/d/1000 pp). Consumption rates for codeine and methamphetamine were 0.05g/d/1000 pp and 0.17g/d/1000 pp, respectively. Consistently across the two WWTPs most of the chemicals (10) showed >80% apparent removal rate from the wastewater, three chemicals showed apparent removal efficiency of approximately 50%; and the removal efficiency could not be assessed for 5 compounds due to their low concentrations in the influent. Based on the fraction of treated and untreated wastewater (10:90) that is released into the receiving environment we estimated a total discharge of approximately 170kg per day of DPCPBs in Ho Chi Minh City.

Stability of alcohol and tobacco consumption biomarkers in a real rising main sewer.

Since alcohol and tobacco consumption are among the leading causes of population health harm, it is very important to understand the consumption behaviour to develop effective harm reduction strategies. Wastewater-based epidemiology (WBE) is a potential tool for estimating their consumption, but there are several uncertainties that need to be determined, including the stability of biomarkers in the sewer. Utilizing a real rising main sewer, this study investigated the stability of alcohol and tobacco consumption biomarkers. Rhodamine and acesulfame were used as flow tracer and benchmarker to understand the transportation of wastewater in the sewer with a hydraulic retention time between 2.7 and 5.0 h. Ethyl sulphate (EtS) and ethyl glucuronide (EtG), two biomarkers of alcohol consumption, were found to have different in-sewer stability, with EtS much more stable than EtG. The degradation rate of EtS is approximately 8% per hour, while EtG has a half-life of 1.9 h. Formation of nicotine, cotinine and trans-3'-hydroxycotinine, three biomarkers for tobacco consumption, was observed during the experiment, probably due to deconjugation of their glucuronide chemicals. The deconjugation process has prevented the determination of actual stability of the three chemicals. However, it is suggested that cotinine is relatively stable, while nicotine and trans-3'-hydroxycotinine degrade to a certain degree in the sewer system. According to our findings, the in-sewer degradation is more important during the interpretation of alcohol consumption estimation than for tobacco consumption estimation.