EPA Takes Action Against Harmful "Forever Chemicals" in the US Water Supply.

This Medical News article discusses new EPA advisories for a class of synthetic chemical compounds known as PFAS, which are ubiquitous in the environment and in humans, as well as new National Academies guidance on expanded testing for exposure.

Revealing drinking water quality issues and possible health risks based on water quality index (WQI) method in the Shanmuganadhi River basin of South India.

The aim of the study is to address the issues and associated health risks due to consumption of high-fluoride water supplied for drinking in a rural part of Shanmuganadhi River basin, Tamil Nadu, India. In this study, 61 groundwater samples were gathered from various tube and open wells and analysed for fluoride and other physicochemical parameters. The abundance of cations is Na+ > Ca2+ > Mg2+ > K+, and that of anions is HCO3- > SO42- > Cl- > F-. The fluoride concentration in drinking groundwater varied from 0.10 to 3.3 mg/l. According to the WHO standards, about 26% of the samples were unfit for drinking requirements (16 out of 61 samples) Water quality index (WQI) method was adopted to categorize the water into different classes to understand its suitability for drinking requirements. WQI signified that nearly 52% of the samples denoted poor, very poor and not suitable categories, whereas 48% of samples denoted good and excellent categories for consumption. Health risks associated with high-fluoride drinking water were assessed for various age groups of inhabitants such as children, teens and adults. The hazard quotient estimated based on the oral intake ranged from 0.00E+00 to 5.50E+00, from 0.00E+00 to 4.22E+00 and from 0.00E+00 to 3.45E+00 for children, teens and adults, respectively. It suggested that the health risks are associated with 75%, 59% and 43% of samples, respectively, among children, teens and adults. Therefore, children are more inclined towards risk than teens and adults in this region based on the intake of fluoride-rich drinking water. To improve the present scenario, groundwater should be either treated before drinking water supply or must be artificially recharged to lower the concentration of ions.

Appraisal of subsurface hydrogeochemical processes in a geologically heterogeneous semi-arid region of south India based on mass transfer and fuzzy comprehensive modeling.

The main aim of the present study was to examine the quality of the groundwater and decipher the sources of groundwater fluoride through mass balance modeling based on fluoride exposure in a geologically heterogeneous semi-arid region of southern India. This was achieved by hydrogeochemical analysis, graphical methods, and mass transfer modeling approaches. Fuzzy comprehensive technique was applied to evaluate the quality of groundwater for groundwater management. In this regard, 61 groundwater samples were obtained from open wells and bore wells and analyzed for different physicochemical parameters. The major cation and anion abundances follow the order Na+ > Ca2+ > Mg2+ > K+ and Cl- > HCO3- > SO42- > NO3- > PO43-. About 88.4% and 34.4% of the total water samples were dominated with Na+ and Cl- ions in this region, respectively. The fluoride level in groundwater ranged from 0.10 to 3.30 mg/l with a mean value of 1.04 mg/l. Nearly 25% of the groundwater samples collected from 15 villages showed fluoride concentrations exceeding the maximum permissible limit of 1.5 mg/l as per the World Health Organization recommendations for human intake. More than 85% of the samples fell under strong acid (Cl- and SO42-) type. The amount of groundwater salinization in this region was 70.5% since the Revelle index (RI) was excess in the groundwater samples (RI > 0.5 meq/l). Silicate weathering, cation exchange, and gypsum dissolution were the dominant geogenic processes in the aquifer system influencing groundwater chemistry and nullified the possibility of carbonate dissolution. Saturation indices revealed the contribution of sequestration of CaCO3 in F- enrichment. Total dissolved solids showed strong positive correlations with Na+, Ca2+, Mg2+, Cl-, SO42- and NO3- indicating the contribution of anthropogenic inputs to groundwater chemistry in addition to geogenic sources. The results of the fuzzy comprehensive method indicated that 33% of the groundwater samples fell under fair water type, 2% and 11% of the samples fell under poor and very poor quality water types, respectively. Therefore, this work will be helpful for the decision-makers to plan for the sustainable management of groundwater resources.

[A new occupational and environmental hazard - nanoplastic]. / Nowe zagrozenie zawodowe i srodowiskowe ­ nanoplastik.

Problems arising from the accumulation of plastic waste in the environment have become global. Appeals to stop the usage of disposable drinking straws or plastic cutlery did not come out without reason - 320 million tons of plastic products are produced annually, of which 40% are disposable items. More and more countries and private enterprises are giving up these types of items in favor of their biodegradable substitutes, e.g., cardboard drinking straws. Plastic waste in the environment is subject to a number of physicochemical interactions and biodegradation in which bacteria are involved. By using synthetic waste, they reduce the size of plastic garbage while increasing its dispersion in the environment. Small plastic particles, invisible to the naked eye, are called nanoplastic. Nanoplastic is not inert to living organisms. Due to its size, it is taken up with food by animals and passed on in the trophic chain. The ability to penetrate the body's barriers through nanoplastic leads to the induction of biological effects with various outcomes. Research studies on the interaction of nanoplastic with living organisms are carried out in many laboratories; however, their number is still a drop in the ocean of the data needed to draw clear-cut conclusions about the impact of nanoplastic on living organisms. There is also no data on the direct exposure to nanoplastic contamination at workplaces, schools and public utilities, standards describing the acceptable concentration of nanoplastic in food products and drinking water, and in vitro tests on nanoparticles other than polystyrene nanoparticles. Complementing the existing data will allow assessing the risks arising from the exposure of organisms to nanoplastic. Med Pr. 2020;71(6):743-56.

A green - high throughput -extraction method based on hydrophobic natural deep eutectic solvent for the determination of emerging contaminants in water by high performance liquid chromatography - diode array detection.

This study reports the use ofa natural deep eutectic solvent (NADES) with hollow fiber-microporous membrane liquid-liquid microextraction (HF-MMLLE) for the multiclass determination of 11 compounds classified as emerging contaminantsin water. Different deep eutectic solvents were synthetized and Thymol: Camphor (1:1 molar fraction) wasused as extraction solvent. The Thymol:Camphor was impregnated into the polypropylene membrane porous for 10 min, replacing commonly used solvents (ex. hexane and octanol). The optimized parameters were obtained by multi and univariate models. Extractions were carried out for 50 min using 1.5 mL of water sample at pH 6 and without addition of salt while desorption was made in a mixture of acetone: methanol (3:1, v/v) for 15 min. Separation/quantification was conducted by HPLC with a diode array detection (DAD)and calibration curves were obtained for each analyte. Determination coefficients higher than 0.9906 and limits of detection ranged from 0.3 to 6.1 µg L-1. Intraday precision (n = 3) ranged from 1.6 to 18.4% and inter day from 5.0 to 21.3%. Relative recoveries were performed in tap and stream water and ranged from 64 to 123%.

Risks of consuming cadmium-contaminated shellfish under seawater acidification scenario: Estimates of PBPK and benchmark dose.

We aim to assess the risks of renal dysfunction and osteoporosis that is attributed to the seawater acidification caused cadmium (Cd) level increase in human consumed shellfish. A physiology-based pharmacokinetic model was used to estimate Cd concentrations in urine and blood among shellfish-only consumers and among the general population. We used the benchmark dose (BMD) method to determine the threshold limits of Cd in urine for renal dysfunction and in blood for osteoporosis for assessing the human health risk. Our results revealed that seawater acidification could increase the Cd accumulation in shellfish by 10-13% compared to the situations under current pH levels. Under the lower seawater pH level, the daily intake of Cd could increase by 21%-67% among shellfish-only consumers, and by 13%-17% among the general population. Our findings indicated that seawater acidification would lead to a marginal increase in Cd intake among humans in shellfish-only consumers. The results of BMDs of urinary Cd showed that the threshold limits for renal dysfunction at 5% were 3.00 µg g-1 in males and 12.35 µg g-1 in females. For osteoporosis, the estimated BMDs of blood Cd were 7.95 µg L-1 in males and 1.23 µg L-1 in females. These results of the risk of Cd intake showed that the consumption of Cd-contaminated shellfish in the general population is largely unaffected by changes in seawater pH levels. Notably, the potential impact of seawater acidification on renal dysfunction for males in shellfish-only consumers face a 14% increase of risk.

An Assessment of the Performance of the PLUS+ Tool in Supporting the Evaluation of Water Framework Directive Compliance in Scottish Standing Waters.

Phosphorus is one of the main causes of waterbodies in Scotland being at less than good ecological status (GES) in terms of the water framework directive (WFD). In Scotland, there are more than 8000 standing waters, defined as lakes and reservoirs that have a surface area of more than 0.5 km2. Only about 330 of these are monitored routinely to assess compliance with the WFD. The export coefficient tool PLUS+ (phosphorus land use and slope) has been developed to estimate total phosphorus (TP) concentrations in the unmonitored sites; modelled values are then compared to WFD target concentrations for high, good, moderate, poor, and bad status to assess compliance. These type-specific or site-specific targets are set by the regulatory authority and form part of a suite of physical, chemical, and ecological targets that are used to assess GES, all of which must be met. During development, the PLUS+ tool was applied to 323 monitored catchments and 7471 unmonitored catchments. The efficacy of the tool was assessed against TP concentrations observed in 2014 and found to perform well in the rural catchments. 51% of standing waters had the same modelled and observed WFD class (i.e., High, Good, Moderate, Poor, Bad), and a further 40% of standing waters had a modelled WFD class that was within one class of observed water quality. The tool performed less well in catchments with larger inputs of TP from urban sources (e.g., sewage). The greatest deviations between measured and modelled classes were explained by the shortage of information on wastewater treatment works, fish farms, migratory birds, levels of uncertainty in TP measurements, and the amount of in-lake re-cycling of P. The limitations of the tool are assessed using data from six well documented case study sites and recommendations for improving the model performance are proposed.

Evaluation of non-carcinogenic risks due to fluoride and nitrate contaminations in a groundwater of an urban part (Coimbatore region) of south India.

Groundwater quality investigations were carried out in one of the urban parts of south India for fluoride and nitrate contaminations, with special focus on human health risk assessment for the rapidly growing and increasingly industrialized Coimbatore City. Twenty-five groundwater samples were collected and analyzed for physico-chemical parameters (EC, pH, TDS, Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, PO43-, NO3-, and F-) and the piper diagram characterized 60% of them as Ca-Mg-Cl type. Analysis of fluoride (0.1 to 2.4 mg/l) shows that 32% of the groundwater samples contain F- over the permissible limit, affecting a region of 122.10 km2. Nitrate (0.1 to 148 mg/l) is over the permissible limit in 44% of the groundwater samples spread over an area of 429.43 km2. The total hazard indices (THI) of non-carcinogenic risk for children (0.21 to 4.83), women (0.14 to 3.35), and men (0.12 to 2.90) shows some of the THI values are above the permissible limit of the US Environmental Protection Agency. The THI-based non-carcinogenic risks are 60%, 52%, and 48% for children, women, and men. This investigation suggests higher health risk for children and also recommends that proper management plan should be adopted to improve the drinking water quality in this region in order to avoid major health issues in the near future.

Evaluation of geochemical baselines and metal enrichment factor values through high ecological quality reference points: a novel methodological approach.

In this study, we propose a new approach to estimate geochemical local baselines and enrichment factor values for metals in riverine sediments. The goal is to describe catchment areas characterized by intensive and spread anthropogenic activities, for which it is challenging to identify undisturbed sites to utilize as reference. The case study is the Nestore river basin (Central Italy). Our approach is based on the use of ecological quality as a criterion to select the reference points in the normalization processes of metal baselines. The rationale is to assume that the sediments with a better environmental quality are anthropogenically least impaired. On these grounds, we detected geochemical local baselines and enrichment factor values of various metals (Ca, Co, Cr, Cu, Mn, Ni, Pb, Se, Sr, and Zn). Also, this approach allowed highlighting a major level of pollution for the most downstream site of Nestore river and its left tributaries.

Attempt of basin-scale sediment quality standard establishment for heavy metals in coastal rivers.

Heavy metal sediment quality standards (SQSs) derived from sediment quality guidelines (SQGs) are crucial in risk evaluation and environmental management. However, the establishment of SQSs is quite complex, especially for heavy metals. This study attempted to establish basin-scale SQSs for Cd, Cu, Pb and Zn based on SQGs combined with water quality standards in two coastal rivers in North China, named Jiaolai River (JL) and Jiahe River (JR), respectively. The spatial distribution, fraction, partition coefficients and environmental risk of heavy metals in sediments-porewater were investigated. The results showed that most heavy metals in sediments in JH were higher than those in JL, however, in the porewater, it exhibited an opposite trend. The geochemical fraction showed that most heavy metals in sediments were dominated by residual fraction. The partition of heavy metals between sediment and porewater were mainly affected by both sediment and porewater properties, and exogenous input of heavy metals. Contamination factors showed that Cd in sediment posed high pollution degree; the interstitial water criteria toxicity units and Nemerow Indexes suggested that heavy metal toxicities in porewater were low. The basin-scale heavy metal SQGs were calculated based on porewater quality derived from surface water quality standards using the modified equilibrium partitioning approach. The basin-scale heavy metal SQGs was classified with different grades to deduce the SQSs. Evaluated results of heavy metals in sediments based on SQSs showed lower potential bio-toxic effects in two rivers. In total, basin-scale SQGs for heavy metals were feasible for basin-scale SQSs establishment in coastal rivers.

Effect of calcite saturation state on the growth and mortality of Heterocypris incongruens and a proposal for an reference artificial sediment in the sediment toxicity test ISO14371.

Since the establishment of the whole-contact sediment toxicity test using Heterocypris incongruens in 2012, this user-friendly method has been widely used for the assessment of many kinds of solid samples, such as sediment, soil, compost, and sewage sludge. There are two endpoints for this method: mortality and growth inhibition. Currently, there is no standard toxicity threshold established for the endpoint of growth inhibition. However, there is evidence showing that the calcite saturation state of the overlying water, which might be different among various samples, influences the growth and survival of H. incongruens. Thus, it is necessary to characterize the influence of the calcite saturation state to ensure that the test results are reliable and comparable among different samples. In the present study, we created artificial sediments comprised of quartz sand and 0-20% calcite particulates to manipulate the calcite saturation state in the overlying water and performed the test using H. incongruens for 6 d. The results show that a low calcite saturation state inhibited the growth of H. incongruens but had no effect on survival rate. The growth of ostracods was linearly related to the calcite saturation index of the overlying water. Additionally, a formula for artificial sediment consisting of 10% calcite and 90% quartz sand for the H. incongruens toxicity test was proposed. This study helps to distinguish H. incongruens growth inhibition caused by calcite saturation from that caused by toxicity.

Recommendations to derive quality standards for chemical pollutants in reclaimed water intended for reuse in agricultural irrigation.

The reuse of treated municipal wastewater (herein referred to as reclaimed water) in agricultural irrigation (RWAI) as a means to alleviate water scarcity is gaining increasing policy attention, particularly in areas where water demand mitigation measures have proved insufficient. However, reclaimed water reuse in practice is lagging behind policy ambition, with <2.5% of it reused in a European context. A key barrier identified as limiting its full valorisation is concern over its impact on human and environmental health. To address this concern, and to meet further objectives including achieving parity between current reclaimed water reuse guidelines operational in various Member States, the European Commission has proposed a regulation which identifies minimum quality requirements (MQR) for a range of microbiological and physico-chemical parameters but the inclusion of compounds of emerging concern (CECs) in terms of the determination of quality standards (QS) is missing. This paper reviews the existing pertinent EU legislation in terms of identifying the need for CEC QS for RWAI, considering the scope and remit of on-going pan-European chemicals prioritisation schemes. It also evaluates opportunities to link in with the existing EQS derivation methodology under the EU WFD to address all protection targets in the environmental compartments exposed via potential pathways of RWAI. Finally, it identifies the main data gaps and research needs for terrestrial ecosystems, the removal efficiency of CECs by WWTPs and transformation products generated during the wastewater reuse cycle.

Tungsten in Washington State surface waters.

At high concentrations, tungsten can be toxic to humans, animals, and the environment, though little is known about natural, aqueous tungsten in surface waters. To improve understanding and develop a model predicting tungsten concentrations, we collected water and sediment from 77 water bodies in 20 watersheds in Washington State, USA. We found aqueous tungsten concentrations spanning two orders of magnitude (10.3 ng L-1 - 2.05 µg L-1) with average tungsten concentrations in both water and sediments more than two-fold higher in watersheds with tungsten-bearing underlying rock types (average: 0.217 µg L-1, 0.669 mg kg-1; range: 0.010-2.05 µg L-1, 0.0713-4.691 mg kg-1 for surface waters and sediments, respectively) than in watersheds without such underlying geology (average: 0.068 µg L-1, 0.352 mg kg-1; range: 0.010-0.211 µg L-1, 0.0349-2.399 mg kg-1 for surface waters and sediments, respectively). Aqueous concentrations of tungsten significantly correlated with beryllium (Be) and copper (Cu) (R2 = 0.31, 0.41, respectively) and a multiple linear regression model using Be and Cu explained 65% of the variance in measured aqueous tungsten concentrations. Applying this model to existing Be and Cu data from 19 sites across the Pacific Northwest resulted in predicted tungsten concentrations ranging from 0.116 to 0.458 µg L-1. These predicted concentrations along with our measured concentrations indicate none of these sites were close to the drinking water standard for tungsten set by the former Soviet Union-the only country so far to set limits for tungsten in drinking water (50 µg L-1).

Deriving safe short-term chemical exposure values (STEV) for drinking water.

Small and brief exceedances of chemicals above their guideline values in drinking water are unlikely to cause an appreciable increased risk to human health. As a result, short-term exposure values (STEV) can be derived to help decide whether drinking water can still be supplied to consumers without adverse health risks. In this study, three approaches were applied to calculate and compare STEV for pesticides. The three approaches included basing a STEV on the acute reference dose (ARfD) (Approach 1), removing conventional attribution rates and uncertainty factors from current guideline values (Approach 2) and extrapolating 1 d and 7 d no observed adverse effect levels (NOAEL) from existing toxicity data using a log-linear regression (Approach 3). Despite being very different methods, the three approaches produced comparable STEV generally within an order of magnitude, which often overlapped with other existing short-term exposure values such as short-term no adverse response levels (SNARL) and health advisories (HA). The results show that adjusting the current guideline value using standard extrapolation factors (Approach 2) often produced the most conservative values. Approach 2 was then applied to two other chemical classes, disinfection by-products (DBPs) and cyanotoxins, demonstrating the wider applicability of the approach.

Seasonal assessment of drinking water sources in Rwanda using GIS, contamination degree (Cd), and metal index (MI).

The quality of drinking water source remains as a major concern in areas of developing and underdeveloped countries worldwide. The treatment and supply of drinking water in Rwanda are carried out by Water and Sanitation Corporation, a state-owned public company. However, it is not able to supply water to all households. Consequently, the non-serviced households depend on natural water sources, like springs, to meet their water requirements. Nevertheless, the water quality in these springs is scarcely known. Therefore, this study assessed and compared metal elements in drinking water sources in the dry and rainy seasons in 2017 using the contamination degree, metal index, and geographic information systems to reveal the spatial distribution of water quality within the considered water sources of springs in Rwanda. The samples were collected monthly from nine water sources of springs and the measured elements are aluminium, calcium, copper, iron, manganese, and zinc. The metal index indicated that during the dry season and rainy season, the sites of Kibungo (1.10 and 1.26) and Kinigi (1.01 and 1.54) have assessed a metal index which is higher than 1. Thus, the water quality of those sites was getting the threshold of warning. The analysis indicated that pollutants are easily transported into water bodies during the rainy season in urban and rural areas to a greater extent than during the dry season .

Influence of season-depending ecological variables on biomarker baseline levels in mussels (Mytilus trossulus) from two Baltic Sea subregions.

For reliable mussel monitoring programmes based on biomarkers, regionally relevant reference values and their natural variability need to be known. The Baltic Sea exhibits high inter-regional and seasonal variability in physical factors such as salinity, temperature and primary production. The aim of this pilot study is to depict the effects of season-related environmental factors in a selected battery of biomarkers in two environmentally different subregions of the Baltic Sea to help establishing reference data for biochemical, cellular and tissue-level biomarkers. In order to achieve that, mussels were collected from reference sites in Kiel (Germany) and Tvärminne (Finland) during three seasons: summer and autumn 2016, and spring 2017. Finally, in order to characterize the ecological situation, analysis of the chemical tissue burden was performed and chlorophyll­a and particulate organic carbon concentration and temperature changes were analyzed at each sampling locality using satellite remote sensing images. An integrated biomarker response index was performed to summarize the biomarker responses of each locality and season. The biochemical endpoints showed seasonal variability regulated by temperature, food supply and reproductive cycle, while among the cellular endpoints only lipofuscin accumulation and lysosomal structural changes showed slight seasonal variation. Seasonal changes in tissue level biomarkers were observed only at the northern Baltic Sea site Tvärminne, dictated by the demanding energetic trade-off caused by reproduction. In conclusion, the characterization of the ecological variables and physico-chemical conditions at each site, is crucial to perform a reliable assessment of the effects of a hypothetical pollution scenario in the Baltic Sea. Moreover, reference levels of biomarkers and their responses to natural environmental conditions must be established.

Cyanobacteria derived taste and odor characteristics in various lakes in China: Songhua Lake, Chaohu Lake and Taihu Lake.

In recent years, increasing eutrophication in large freshwater lakes, which are an important drinking water source for cities in China, have been resulted in substantial cyanobacteria blooms that could cause serious taste and odor (T&O) problems. In this investigation, three typical lakes (Songhua Lake, Chaohu Lake and Taihu Lake) as drinking water sources located in different geographical areas in China, were selected to study the problems of cyanobacteria-derived T&O (i.e., 2-methylisobornoel, geosmin, ß-ionone, 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, and 2-methylbenzofuran). The occurrence of T&O in target lakes was compared across various nutrition states and geographic locations, to get more information for early warning for algal bloom and T&O occurrence, being useful lake water management and purification. Results show that the occurrence of T&O in Songhua Lake was the poorest for the lowest nutrient state, as a first report in T&O research field in China. This is a lake located in Northeast China at high latitude, with lower water temperatures. The occurrence of T&O in Chaohu Lake was ranked in the middle. That in Taihu Lake was the most intensive. Finally, the relationship between water quality, T&O and its origin was analyzed by multivariate statistical methods (correlation analysis, principal component, and cluster analyses).

Comparing three Australian natural organic matter isolates to the Suwannee river standard: Reactivity, disinfection by-product yield, and removal by drinking water treatments.

Water treatments that provide efficient removal of organic and inorganic disinfection by-product (DBP) precursors across variable natural organic matter (NOM) sources are desirable. Treatments that effectively remove inorganic DBP precursors such as bromide, which significantly shift the speciation of DBP formation towards more toxic DBPs, are of particular interest and have been less investigated. This study characterised NOM isolated from three major drinking water sources in Southeast Queensland (SEQ), Australia, and compared it to the International Humic Substances Society (IHSS) Suwannee River NOM isolate (SR) in terms of DBP precursor removal treatments and DBP formation. Each NOM isolate was used to make synthetic water samples with otherwise identical water quality parameters, that were treated with enhanced coagulation (EC) or EC followed by; anion exchange (MIEX® resin), powdered activated carbon (PAC), granular activated carbon (GAC) or silver impregnated activated carbon (SIAC), to investigate the removal of DBP precursors (bromide and DOC), minimisation of DBPs, as well as the change in specific chlorine demand. EC/SIAC treatment was the most effective method of DBP control studied, due to the efficient simultaneous NOM and bromide adsorption of the SIAC (99 ±â€¯1% bromide removal regardless of NOM source). This treatment also resulted in >92% removal of each of the measured DBPs across all NOM sources, with the exception of DBAN and 1,1-DCP, which achieved >80% removal across all NOM sources. Increases in tribromomethane (TBM) and dibromoacetonitrile (DBAN) formation were observed after all other treatment/NOM-isolate combinations, due to increased Br:DOC ratio after treatment, whereas chlorinated DBPs were generally well-controlled by all treatment/NOM-isolate combinations. Differences in reactivity of the individual NOM isolates were found to be related to both the origin of the isolate and the treatment employed, however, bromide removal capacity for each treatment was independent of NOM source.

Comprehensive Target Analysis for 484 Organic Micropollutants in Environmental Waters by the Combination of Tandem Solid-Phase Extraction and Quadrupole Time-of-Flight Mass Spectrometry with Sequential Window Acquisition of All Theoretical Fragment-Ion Spectra Acquisition.

There are many thousands of chemicals in use for a wide range of purposes, and highly efficient analytical methods are required to monitor them for protection of the environment. In order to cope with this difficult task we developed a novel, comprehensive method for 484 substances in water samples. In this method target chemicals were extracted by tandem SPE and then determined by LC-QTOF-MS-SWATH. Targets were unambiguously identified using retention times, accurate masses of a precursor and two product ions, their ion ratios, and accurate MS/MS spectrum. Quantitation was achieved by the internal standard method using a precursor ion. Results of recovery tests at two concentrations (50 and 500 ng L-1) showed average recoveries of 87.5% and 87.0% (RSD, 9.1% and 9.4%), respectively. Limits of detection of one-half of the targets were below 1.0 ng L-1. The method was applied to the influent and effluent of a sewage treatment plant, and around 100 chemicals were detected. Results of examination on matrix effects using their extracts spiked with 209 pesticides showed that the ratios of detected amounts between the extracts and the standard solution were 89.8% (influent) and 91.7% (effluent), respectively. In addition, investigation on the stability of calibration curves by injecting the same standards for 1 year showed that their quantitative results did not change; average accuracy was 103.3% (RSD, 10.0%), indicating that the calibration curves can be used for an extended period of time without calibration, and quantitative retrospective analysis can be done after creating calibration curves for new targets.