Road runoff is an important vector for the transport of chemicals originating from tire wear into receiving waters. In this study, samples of surface water were collected in the summer of 2020 from ...two rivers near high-traffic corridors in the Greater Toronto Area (GTA) in Canada. These samples were analyzed for two additives used in tire production, 1,3-diphenyl guanidine (DPG) and hexamethoxymethylmelamine (HMMM), as well 26 of the transformation compounds of HMMM. In addition, samples were analyzed for 6PPD-quinone (6PPD-q), an oxidation by-product of a tire additive that was recently identified as a candidate compound responsible for mass mortalities of Coho salmon (Oncorhynchus kisutch) in spawning streams in the USA. Grab and composite samples were collected during rain events (i.e., wet events) at both locations. Grab samples were collected from the Don River upstream, downstream and at the point of discharge from a municipal wastewater treatment plant (WWTP) during a period of dry weather. Of the target analytes, 6PPD-q, DPG and HMMM, as well as 15 of the transformation compounds of HMMM, were detected at concentrations above limits of quantitation. The concentrations of 6PPD-q in the receiving waters during wet events were within the range of the LC50 for adult Coho salmon. One of the transformation products (TPs) of HMMM, dimethoxymethylmelamine was detected in a composite sample from Highland Creek at an estimated concentration greater than 10 μg/L, indicating that more research is needed to evaluate the potential hazards to the aquatic environment from this compound. Sampling in the Don River during a dry period showed that discharges of wastewater from WWTPs are also continuous sources of the TPs of HMMM. This study contributes to the growing literature showing that chemicals derived from tire wear are ubiquitous in urban watersheds and may be a significant hazard to aquatic organisms.
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•Compounds derived from tire wear were detected in rivers in the Greater Toronto Area.•Hexamethoxymethyl-melamine and 17 transformation compounds were detected.•A toxic by-product of 6PPD (6PPD-quinione) and diphenylguanidine were also detected.•Estimated concentrations of 6PPD-quinone approached toxic thresholds.
Prompted by a recent report that 6PPD-quinone (6PPD-q), a by-product of a common tire manufacturing additive that is present in road runoff, is toxic to coho salmon (
Oncorhynchus kisutch
), extracts ...of water samples collected from an urban river were re-analyzed to determine if this compound was present in stormwater-influenced flows. In addition, extracts were analyzed for 1,3-diphenylguanidine (DPG), which is also used in tire manufacturing. Samples were originally collected in the fall of 2019 and winter of 2020 in the Greater Toronto Area of Canada from the Don River, a highly urbanized watershed in close proximity to several major multi-lane highways. These target compounds were analyzed using ultra-high pressure liquid chromatography with high resolution mass spectrometric detection with parallel reaction monitoring. Both 6PPD-q and DPG were detected above limits of quantification (i.e., 0.0098 µg/L) in all extracts. Maximum concentrations for 6PPD-quinone of 2.30 ± 0.05 µg/L observed in the river during storm events exceeded the LC
50
for this compound for coho salmon (i.e., > 0.8 µg/L). In composite samples collected at intervals throughout one rain event, both compounds reached peak concentrations a few hours after initiation of the event (i.e., 0.52 µg/L for DPG and 2.85 µg/L for 6PPD-q), but the concentrations of 6PPD-q remained elevated above 2 µg/L for over 10-h in the middle of the event. Estimates of cumulative loads of these compounds in composite samples indicated that kg amounts of these compounds entered the Don River during each hydrological event, and the loads were proportional to the amounts of precipitation. This study contributes to the growing literature indicating that potentially toxic tire-wear compounds are present at elevated levels and are transported via road runoff into urban surface waters during rain events.
Hexamethoxymethyl-melamine (HMMM) is used as a crosslinking agent in resins and plastics and in the manufacture of tires. In the present study, surface water samples were collected from two rivers ...adjacent to high traffic highways in the Greater Toronto Area in Ontario, Canada. Composite samples collected from the Don River and Highland Creek during rain events and a period of rapid snowmelt were preconcentrated using solid phase extraction and analyzed using liquid chromatography with high-resolution mass spectrometry. Elevated concentrations (> 1 µg/L) of HMMM were detected in surface waters during rain events in October of 2019 and during snow melt in early March of 2020. There were lower average concentrations of HMMM detected during rain events in the winter and spring of 2020. Temporal profiles of changes in the concentrations of HMMM in composite samples collected every 3 h during a rain event in October 2019 closely corresponded to the hydrograph profiles at the sampling sites, with the HMMM concentrations peaking > 6 h after the peak in water levels. This work contributes to the literature showing that HMMM is a ubiquitous contaminant of urban watersheds and that runoff from roads is a vector for the transport of this compound into urban surface waters.
In the present study, 29 chemicals derived from tire wear were monitored by deploying Polar Organic Chemical Integrative Samplers (POCIS) in four WWTPs and two drinking water treatment plants (DWTPs) ...located in a municipality in southern Ontario, Canada. Target analytes included 1,3-diphenylguanidine (DPG), the oxidation byproduct of N-(1,3-dimethylbutyl)-N′-phenyl-1,4-benzenediamine called 6PPD-quinone, hexamethoxymethylmelamine (HMMM), and 26 of HMMM’s known transformation products (TPs). This study is the first to monitor all these target compounds in DWTPs, as well as to report data for the presence of 6PPD-quinone in WWTPs. HMMM and selected TPs of this compound were detected in POCIS deployed in the WWTPs and in the DWTPs. The maximum estimated time-weighted average (TWA) concentration of HMMM of 83.2 ± 25.2 ng/L was observed in the effluent of one of the WWTPs. The TWA concentrations were not determined for any of the other target analytes, as POCIS sampling rates have not been determined for these chemicals. The total mass of HMMM and its TPs accumulated on POCIS frequently exceeded 4000 ng and the masses were generally lower in WWTP effluents relative to the influents. For other target analytes, the amounts accumulated on POCIS deployed in WWTP effluents frequently exceeded the amounts accumulated on POCIS deployed in the influents. DPG was detected in POCIS deployed in both the WWTPs and the DWTPs, and 6PPD-quinone was detected in POCIS deployed in both the influent and the effluent of WWTPs. We speculate that these tire wear compounds are entering WWTPs through stormwater overflows into the sewers or from commercial sources (e.g., car washes). This study highlights the need for an assessment of both WWTPs and DWTPs as sinks and sources of these tire wear compounds and the efficacy of treatment processes to remove them from both wastewater and drinking water.
Because of the persistence and solubility of neonicotinoid insecticides (NNIs), there is concern that these compounds may contaminate sources of drinking water. The objective of this project was to ...evaluate the distribution of NNIs in raw and treated drinking water from selected municipalities that draw their water from the lower Great Lakes in areas of southern Ontario, Canada where there is high intensity agriculture. Sites were monitored using Polar Organic Chemical Integrative Samplers (POCIS) and by collecting grab samples at six drinking water treatment plants. Thiamethoxam, clothianidin and imidacloprid were detected in both POCIS and grab samples of raw water. The frequency of detection of NNIs was much lower in treated drinking water, but some compounds were still detected at estimated concentrations in the low ng L−1 range. Thiamethoxam was detected in one grab sample of raw drinking water at a mean concentration of 0.28 μg L−1, which is above the guidelines for drinking water recommended in some jurisdictions, including the European Union directive on pesticide levels <0.1 μg L−1 in water intended for human consumption. Further work is required to determine whether contamination of sources of drinking water with this class of insecticides is a global problem in agricultural regions.
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•Neonicotinoid insecticides detected in drinking water in rural municipalities in Canada.•A novel method was developed for estimating concentrations from POCIS passive samplers.•Thiamethoxam, clothianidin and imidacloprid present at the highest concentrations.•Thiamethoxam detected in a grab sample of raw drinking water at mean concentration of 0.28 μg L−1.
A sensitive and accurate method was developed for the simultaneous determination of triclosan and triclocarban in sludge and treated biosolids from municipal wastewater treatment plants (WWTPs). The ...methods involved extraction by pressurized liquid extraction (PLE), followed by sample clean-up on a Oasis HLB solid phase extraction (SPE) cartridge and analysis by liquid chromatography with electrospray ionization and tandem mass spectrometry (LC–ESI-MS/MS). Accurate quantification was achieved by isotope dilution using stable isotopes of triclosan and triclocarban as internal standards. Matrix effects (ME) in samples of spiked biosolids (
n
=
5) were evaluated by a standard addition method, and these analyses indicated mean ME values of 79.7
±
6.7 and 100.5
±
8.4% for triclosan and triclocarban, respectively; indicating that the sample clean-up method effectively removed interferences. The mean recoveries from the spiked biosolids sample were 97.7
±
6.2 and 98.3
±
5 for triclosan and triclocarban, respectively, and the limits of detection (LOD) were 1.5 and 0.2
ng/g (d.w.) for triclosan and triclocarban, respectively. The method was applied to the analysis of triclosan and triclocarban in samples of activated sludge and treated biosolids collected from three WWTPs in Ontario, Canada. These preliminary results indicate that triclosan and triclocarban co-occur in municipal sludge and treated biosolids at concentrations ranging from 0.62 to 11.55
μg/g dry weight for triclosan, and from 2.17 to 5.97
μg/g dry weight for triclocarban.
It is well established that persistent organic pollutants are transported long distances in the atmosphere and deposited into aquatic and terrestrial ecosystems in remote areas, including high ...altitude lakes. The objective of this research was to evaluate whether compounds of wastewater origin were present in four remote upland headwater lakes in Ireland that primarily receive loadings from atmospheric deposition. Using Polar Organic Chemical Integrative Samplers (POCIS) deployed in the lakes for 60 to 68 days, seven compounds were detected at levels that could be quantified but 25 of the target compounds were not detected. The detected compounds included the cannabinoid metabolite, tetrahydrocannabinol carboxylate (THC-COOH), codeine, acetaminophen (paracetamol), ibuprofen, and the artificial sweeteners, sucralose, and saccharin, which were all present at concentrations estimated to be < 125 ng/L. Caffeine was also present in the lakes at estimated concentrations between 213 and 1320 ng/L. Cocaine and tramadol were detected in POCIS deployed in some of the lakes, but at levels below the limits of quantitation. The highest concentrations of the target analytes were detected in two lakes located in the eastern part of Ireland. These data are consistent with regional atmospheric transport of these compounds originating from wastewater treatment plants in Ireland. However, contaminants from wastewater treatment plants in the United Kingdom may also be a source in these upland lakes that are located far from emissions of urban pollution.
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•POCIS passive samplers were deployed in four remote upland lakes in Ireland.•Of 34 target compounds, seven compounds could be quantified, including caffeine.•A metabolite of tetrahydrocannabinol was one of the compounds detected.•Wastewater treatment plants in Ireland and the United Kingdom are the likely sources.
In this study, we evaluated the distribution and concentrations of a range of neonicotinoid insecticides (NNIs) and other insecticides, fungicides, biocides and selected herbicides in watersheds that ...drain into the lower Great Lakes in Ontario, Canada. Polar Organic Chemical Integrative Samplers (POCIS) were deployed in 18 watersheds during late May to late June of 2016. Grab samples were also collected in 7 of these watersheds. There was generally good agreement between the time-weighted average concentrations of pesticides estimated from the POCIS and the concentrations detected in grab samples. The NNIs, thiamethoxam, clothianidin and imidacloprid, were present in several watersheds at concentrations that exceeded the Canadian Water Quality Guideline for imidacloprid of 0.23 μg/L. The new generation insecticides, flonicamid and flupyradifurone were also detected in some watersheds, which is the first report of these pesticides in the peer-reviewed literature. Atrazine, 2,4-D, dicamba, carbendazim, thiophanate methyl and several azole-based fungicides were also widely detected. Discriminant Function Analysis (DFA) indicated that a high proportion (i.e. >80%) of the watersheds could be discriminated from each other on the basis of the pattern of pesticides detected in surface waters, and the proportion of field crops in the watershed.
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•Neonicotinoid insecticides in some watersheds in Ontario, Canada exceeded the Canadian Water Quality Guideline.•The new generation insecticides, flonicamid and flupyradifurone were detected in some watersheds.•The pharmaceutical, fluconazole may be transported to watersheds from applications of biosolids to fields.•A high proportion of watersheds could be classified by patterns of land use and the pesticides in surface waters.
Pharmaceutically active compounds (PhACs) are discharged into the environment from domestic wastewater treatment plants (WWTPs). In this study, we determined the distribution of the anti-epileptic ...drug, carbamazepine (CBZ), and its major metabolites and caffeine in both aqueous and solid phases through different treatment processes of a WWTP. A method was developed to extract samples of biosolids using pressurized liquid extraction (PLE), coupled with cleanup of extracts using solid-phase extraction. Samples of biosolids and wastewater were analyzed for caffeine and CBZ and five of its metabolites, 10,11-dihydro-10,11-epoxycarbamazepine (CBZ-EP), 11-dihydro-10,11-epoxycarbamazepine (CBZ-DiOH), 2-hydroxycarbamazepine (CBZ-20H), 3-hydroxycarbamazepine (CBZ-30H), and 10,11-dihydro-10-hydroxycarbamazepine (CBZ-100H). The analytes were quantified using liquid chromatography-electrospray ionization tandem mass spectrometry. The recoveries of the analytes were 82.1-91.3% from raw biosolids and 80.1-92.4% from treated biosolids, and the limits of detection were 0.06-0.50 and 0.06-0.40 microg/kg on a wet weight basis for raw and treated biosolids, respectively. The behavior of carbamazepine and its metabolites, together with caffeine as a marker of domestic inputs, was investigated in the WWTP for the City of Peterborough, ON, Canada, which utilizes secondary sewage treatment technologies. CBZ, CBZ-2OH, CBZ-30H, and CBZ-DiOH were detected at concentrations of 69.6, 1.9, 1.6, and 7.5 microg/kg (dry weight), respectively, in untreated biosolids and at concentrations of 258.1, 3.4, 4.3, and 15.4 microg/kg (dry weight), respectively, in treated biosolids. However, CBZ-EP and CBZ-100H were not detected in any of the biosolid samples. CBZ and its five metabolites were detected in all wastewater samples collected from four different stages of treatment. The results showed that 29% of the carbamazepine was removed from the aqueous phase during treatment in the WWTP, while the metabolites were not effectively removed. Concentrations of caffeine were reduced by 99.9% in the aqueous phase, which appeared to be due primarily to degradation. Caffeine was also detected at concentrations of 165.8 and 7.6 microg/kg (dry weight) in raw and treated biosolids, respectively. Because of differences in hydrophobicity, CBZ is the primary analyte in biosolids, while CBZ-DiOH is the primary analyte in the aqueous phase of the wastewater. A mass balance calculation showed that the majority of CBZ and its metabolites exist in the aqueous phase (i.e., wastewater), ratherthan in the biosolids, 78 g of CBZ and its metabolites enters the Peterborough WWTP daily, and 91 g is discharged from the WWTP daily in the combined suspended solids and aqueous phases of the wastewater. The calculated daily inputs into the WWTP are somewhat less than the inputs of 192 g estimated from Canadian annual sales data for CBZ.
Several drugs of abuse, including amphetamines, cocaine and its metabolite, benzoylecgonine and several opioid prescription drugs were detected in wastewater from two Canadian cities, a small ...community (75,000 population) and a large urban center (1.6million population). The objective of this study was to evaluate community use of these drugs in two cities with large differences in population size and demographics. In addition, we evaluated the use of the Polar Organic Chemical Integrative Sampler (POCIS) as a monitoring tool for drugs of abuse. Heroin was not detected at either location, probably because this illicit drug is metabolized to morphine prior to excretion. Acetylcodeine and acetylmorphine were also not detected. Estimates of community consumption from wastewater analysis indicated that the most widely used drug was cocaine at a median level of consumption in the larger city of approximately 38 doses per day per 1000 people. Consumption of the substituted amphetamine, ephedrine, as well as methamphetamine was also higher in the larger city, at 21 and 1.8 doses per day per 1000 people, respectively. Use of amphetamine, MDMA and tramadol were similar in both centers, but use of oxycodone was greater in the smaller city. Use of MDMA (ecstasy) peaked on weekends. Ketamine was detected in wastewater from the larger city; the first report of abuse of this veterinary anesthetic in a North American city. POCIS sampling rates were determined for the first time for 7 of the target compounds. Comparing the time weighted average concentrations estimated from POCIS data to the concentrations obtained from 24-h composite samples, the data were generally comparable, except for some compounds which were not detected in POCIS deployed in the untreated wastewater, probably because of biofouling or accumulation of debris on the cages containing the POCIS. This study indicates that the size and demographics of population centers can influence the patterns of abuse of drugs.
•One of only a few reports on community use of opioid drugs; first for North America.•Evidence of high oxycodone use and consumption of ketamine is found in selected communities.•Sampling rates for passive samplers are determined for the first time for 7 drugs.•POCIS is useful for monitoring in treated WW, but has limited applicability in untreated WW.
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