Semirational Design Strategy To Enhance the Thermostability and Catalytic Activity of Cytochrome P450 105D7 for the Degradation of the Pharmaceutically Active Compounds: Diclofenac.

Pharmaceutically active compounds are an important category of emerging pollutants, and their biological transformation processes in the environment are crucial for understanding and evaluating the migration, transformation, and environmental fate of emerging pollutants. The cytochrome P450 105 enzyme family has been proven to play an important role in the degradation of exogenous environmental pollutants. However, its thermostability and catalytic activity still need to be improved to better adapt to complex environmental conditions. This work elucidates the key mechanisms and important residues of the degradation reaction through multiple computational strategies, establishes a mutation library, and obtains 21 single-point mutation designs. Experimental verification showed that 16 single mutants had enhanced thermostability, with the R89F and L197Y mutants showing the highest increases in thermostability at 135 and 119% relative to the wild-type enzyme, respectively. Additionally, as a result of the higher specific activity of D390Q, it was selected for combination mutagenesis, ultimately resulting in three combination mutants (R89F/L197Y, R89F/D390Q, and R89F/L197Y/D390Q) with enhanced thermostability and catalytic activity. This study provides a modification approach for constructing efficient enzyme variants through semirational design and can contribute to the development of control technologies for emerging pollutants.

Pharmaceutically active compounds removal from aqueous solutions by MIL-101(Cr)-NH2: A molecular dynamics study.

Discharging pharmaceutically active drugs into water and wastewater has become a significant environmental threat. Traditional methods are unable to effectively remove these compounds from wastewater, so it is necessary to search for more effective methods. This study investigates the potential of MIL-101(Cr)-NH2 as a preferable and more effective adsorbent for the adsorption and removal of pharmaceutically active compounds from aqueous solutions. By utilizing its large porosity, high specific surface area, and high stability, the structural and transport properties of three pharmaceutically active compounds naproxen (NAP), diclofenac (DIC) and sulfamethoxazole (SMX)) studied using molecular dynamics simulation. The results indicate that the MIL-101(Cr)-NH2 adsorbent is suitable for removing drug molecules from aqueous solutions, with maximum adsorption capacities of 697.75 mg/g for naproxen, 704.99 mg/g for diclofenac, and 725.51 mg/g for sulfamethoxazole.

Antibiotic residue contamination in the aquatic environment, sources and associated potential health risks.

Antibiotic residues are widely recognized as major pollutants in the aquatic environment on a global scale. As a significant class of pharmaceutically active compounds (PhACs), antibiotics are extensively consumed worldwide. The primary sources of these residues include hospitals, municipal sewage, household disposal, and manures from animal husbandry. These residues are frequently detected in surface and drinking waters, sewage effluents, soils, sediments, and various plant species in countries such as China, Japan, South Korea, Europe, the USA, Canada, and India. Antibiotics are used medicinally in both humans and animals, with a substantial portion excreted into the environment as metabolites in feces and urine. With the advancement of sensitive and quantitative analytical techniques, antibiotics are consistently reported in environmental matrices at concentrations ranging from nanograms per liter (ng/L) to milligrams per liter (mg/L). Agricultural soils, in particular, serve as a significant reservoir for antibiotic residues due to their strong particle adsorption capacities. Plants grown in soils irrigated with PhAC-contaminated water can uptake and accumulate these pharmaceuticals in various tissues, such as roots, leaves, and fruits, raising serious concerns regarding their consumption by humans and animals. There is an increasing need for research to understand the potential human health risks associated with the accumulation of antibiotics in the food chain. The present reviews aims to shed light on the rising environmental pharmaceutical contamination concerns, their sources in the environment, and the potential health risks as well as remediation effort. To discuss the main knowledge gaps and the future research that should be prioritized to achieve the risk assessment. We examined and summarized the available data and information on the antibiotic resistance associated with antibiotic residues in the environment. As studies have indicated that vegetables can absorb, transport, and accumulate antibiotics in edible parts when irrigated with wastewater that is either inadequately treated or untreated. These residues and their metabolites can enter the food chain, with their persistence, bioaccumulation, and toxicity contributing to drug resistance and adverse health effects in living organisms.

Pharmaceutically active compounds in aqueous environment: recent developments in their fate, occurrence and elimination for efficient water purification.

The existence of pharmaceutically active compounds (PhACs) in the water is a major concern for environmentalists due to their deleterious effects on living organisms even at minuscule concentrations. This review focuses on PhACs such as analgesics and anti-inflammatory compounds, which are massively excreted in urine and account for the majority of pharmaceutical pollution. Furthermore, other PhACs such as anti-epileptics, beta-blockers and antibiotics are discussed because they also contribute significantly to pharmaceutical pollution in the aquatic environment. This review is divided into two parts. In the first part, different classes of PhACs and their fate in the wastewater environment are presented. In the second part, recent advances in the removal of PhACs by conventional wastewater treatment plants, including membrane bioreactors (MBRs), activated carbon adsorption and bench-scale studies concerning a broad range of advanced oxidation processes (AOPs) that render practical and appropriate strategies for the complete mineralization and degradation of pharmaceutical drugs, are reviewed. This review indicates that drugs like diclofenac, naproxen, paracetamol and aspirin are removed efficiently by conventional systems. Activated carbon adsorption is suitable for the removal of diclofenac and carbamazepine, whereas AOPs are leading water treatment strategies for the effective removal of reviewed PhACs.

In-situ chemical attenuation of pharmaceutically active compounds using CaO2: Influencing factors, mechanistic modeling, and cooperative inactivation of water-borne microbial pathogens.

Water polluted by pharmaceutically active compounds (PhACs) and water-borne pathogens urgently need to develop eco-friendly and advanced water treatment techniques. This paper evaluates the potential of using calcium peroxide (CaO2), a safe and biocompatible oxidant both PhACs (thiamphenicol, florfenicol, carbamazepine, phenobarbital, and primidone) and pathogens (Escherichia coli, Staphylococcus aureus) in water. This paper evaluates the potential of using calcium peroxide (CaO2) as a safe and biocompatible oxidant to remove both PhACs (thiamphenicol, florfenicol, carbamazepine, phenobarbital, and primidone) and pathogens (Escherichia coli, Staphylococcus aureus) in water. The increased CaO2 dosage increased efficiencies of PhACs attenuation and pathogens inactivation, and both exhibited pseudo-first-order degradation kinetics (R2 > 0.90). PhACs attenuation were mainly via oxidization (H2O2, •OH/O•-, and O2•-) and alkaline hydrolysis (OH-) from CaO2. Moreover, concentrations of these reactive species and their contributions to PhACs attenuation were quantified, and mechanistic model was established and validated. Besides, possible transformation pathways of target PhACs except primidone were proposed. As for pathogen indicators, the suitable inactivation dosage of CaO2 was 0.1 g L-1. The oxidability (18-64%) and alkalinity (82-36%) generated from CaO2 played vital roles in pathogen inactivation. In addition, CaO2 at 0.01-0.1 g L-1 can be applied in remediation of SW contaminated by PhACs and pathogenic bacteria, which can degrade target PhACs with efficiencies of 21-100% under 0.01 g L-1 CaO2, and inactivate 100% of test bacteria under 0.1 g L-1 CaO2. In short, capability of CaO2 to remove target PhACs and microbial pathogens reveals its potential to be used as a representative technology for the advanced treatment of waters contaminated by organic compounds and microbial pathogens.

Status of pharmaceuticals in the Korle Lagoon and their toxicity to non-target organisms.

The availability of pharmaceutically active compounds (PhACs) in surface waters and suspended solids/sediments presents an ecological hazard of chronic exposure to non-target organisms. Thus, water and sediment samples were collected from the Korle Lagoon in the west of Accra-Ghana city center to evaluate 35 medicinal drugs belonging to the main therapeutic classes and their toxicity to non-target organisms (i.e., fish, daphnid, and algae). High-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) was employed to analyze the levels of PhACs in the samples. PhACs levels in water samples were higher compared to PhACs levels in sediment samples. Acetaminophen, ibuprofen, tramadol, and Diclofenac were the PhACs that showed a higher frequency of detections and higher average concentrations. Diazepam, mefenamic acid, indomethacin, gemfibrozil, and glibenclamide exhibited a higher frequency of detections, but their average concentrations in both sample types were lower. The calculated risk index values for acetaminophen and ibuprofen suggested low ecological risks to fish, while tramadol showed medium to high ecological risks to daphnid. In contrast, acetaminophen and fenofibrate showed low ecological risks to daphnid. Additionally, the risk index values for fenofibrate suggested medium to high ecological risks to algae, while tramadol exhibited low ecological risks to algae. The other PhACs showed negligible ecological risks to non-target organisms. The calculated toxic unit values for each sampled site suggested a medium adverse ecological risk to non-target organisms. Based on the results obtained, the availability of PhACs in the studied area will have adverse effects on studied non-target organisms. The negative impacts of PhACs on non-target organisms may cause an imbalance in the food chain process, leading to a decrease in fish production and a reduction in fish quality. The result of this study is evidence of public health threat because the accumulation of PhACs in fish species may also cause some kinds of hormonal, chemical, and molecular changes within the various systems of the fishes to be toxic or unpleasant for humans' consumption.

Simultaneous determination of pharmaceuticals and metabolites in fish tissue by QuEChERS extraction and UHPLC Q/Orbitrap MS analysis.

In recent years, the occurrence, fate, and adverse effects of pharmaceutically active compounds (PhACs) in aquatic organisms have become a noteworthy issue. In the present study, a rapid and sensitive multiresidue analytical method was developed for the determination of 18 parent PhACs and 5 metabolites in sea bream (Sparus aurata), by combining a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure with ultra-high performance liquid chromatography-Orbitrap-mass spectrometry (UHPLC-Orbitrap-MS). The method development involved optimization of extraction solvent, extraction salts, clean-up sorbents, and amount of sample evaluation, while identification on Orbitrap MS was based on accurate mass and further confirmation with MS/MS fragmentation. The developed method was validated, and linearity was higher than 0.99. Recoveries in all cases ranged between 62 and 107% (at 10, 50, and 100 ng g-1), while intra-day and inter-day precision, expressed as relative standard deviation, RSD, was lower than 4% and 7%, respectively. In addition, limits of quantification (LOQs) ranged between 0.5 and 19 ng g-1. The compounds presented a low matrix effect, between - 13 and 4%, while the expanded uncertainty U% estimated at the three spiking levels 10, 50, and 100 ng g-1 was found below 49% in all cases. Finally, the validated method was applied to sea bream samples from an aquaculture farm located in the Mediterranean Sea, with one positive finding for the antibiotic trimethoprim at a concentration of 26 ng g-1, presenting negligible human health risk.

Issues, challenges, directives, and limitations concerning the improvement of environmental risk assessment of pharmaceutically active compounds.

Nowadays, when tons of different chemicals including pharmaceutically active compounds (PhACs) are known to be released into the environment, applying adequate risk assessment relating to the protection of the ecosystem is very important. A broad body of scientific papers expresses a growing demand for improvement of the method(s) for ecological/environmental risk assessment (ERA). Although certain issues about ERA often emerge in the community, most of them cannot be considered as real problems and its methodology was developed keeping several limitations in mind. Nevertheless, the current approaches can be improved in order to better serve the intended purposes. For example, there is a lack of an integrated, manageable ecotoxicological database. It is not uncommon for basic, but extremely important, influencing factors such as time of exposure, interactions between different compounds, and characteristics of different habitats to be ignored. Discussing under the basic regulatory framework used in the EU, this correspondence paper deals with these and other examples to present the current features of ERA, identify gaps in process and application, and propose possible improvements/directives.

Simultaneous determination of 44 pharmaceutically active compounds in water samples using solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry.

This study examines an improved and simplified method for solid-phase extraction (SPE), which offers rapid and accurate determination and identification of 44 pharmaceutically active compounds using ultra-performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS). The common active compounds include four macrolides, seventeen sulfonamides, four quinolones, chloramphenicol, eight ß-lactams, four tetracyclines, lincomycin, amantadine, 4-acetamidophenol, phenylbutazone, trimethoprim, clenbuterol, and hydrocortisone in water samples. We optimized crucial parameters of MS/MS, UPLC, and SPE and studied the matrix effect related to the modified analytical process from water samples. The matrix-matched calibration curves were accomplished at seven concentration levels and a satisfactory linear relationship (r2 > 0.994) was observed within the range of 0.1-500 ng/mL. Results show varying limits of detection (0.0111-0.966 ng/L for different analytes based on signal-to-noise (S/N) = 3) and limits of quantitation (0.0382-3.26 ng/L). Recoveries of the spiked samples ranged from 75.7 to 108% with relative standard deviation lower than 9.6%. The proposed method was successfully applied to the analysis of real samples.

Utilization of biosolids for glucose oxidase production: A potential bio-fenton reagent for advanced oxidation process for removal of pharmaceutically active compounds.

The current work focuses on the production of glucose oxidase (GOD) in sterilized biosolid (BS) slurries containing BS and municipal wastewater effluent. Various parameters were optimized for maximizing the GOD production and the effects of biostimulation on GOD production was investigated by adding synthetic media components. The studies on inoculum characteristics at an inoculum age of 72 h and inoculum size of 20% (w/v) produced high GOD activities of around 6012 U/L in 25% (dw/v) BS media. Further, the effect of ultrasonication time was determined to release BS-bound GOD in order to maximize enzymes recovery. Using 1000 U/L of the BS-based GOD for 0.55 M glucose oxidation produced the maximum H2O2 concentration of 216 ppm. The produced H2O2 was utilized for bio-Fenton based advanced oxidation process for the partial removal of 15 pharmaceutically active compounds.

Risk assessment of pharmaceutically active compounds (PhACs) in the Klang River estuary, Malaysia.

The concentration profile, distribution and risk assessment of pharmaceutically active compounds (PhACs) in the coastal surface water from the Klang River estuary were measured. Surface coastal water samples were extracted using offline solid phase, applying polymeric C18 cartridges as extraction sorbent and measuring with liquid chromatography mass spectrometry-mass spectrometry (LC MS-MS) technique. Extraction method was optimized for its recovery, sensitivity and linearity. Excellent recoveries were obtained from the optimized method with percentage of recoveries ranging from 73 to 126%. The optimized analytical method achieved good sensitivity with limit of detection ranging from 0.05 to 0.15 ng L-1, while linearity of targeted compounds in the LC MS-MS system was more than 0.990. The results showed that amoxicillin has the highest concentration (102.31 ng L-1) followed by diclofenac (10.80 ng L-1) and primidone (7.74 ng L-1). The percentage of contribution (% of total concentration) for the targeted PhACs is in the following order; amoxicillin (92.90%) > diclofenac (3.95%) > primidone (1.23%) > dexamethasone (0.75%) > testosterone (0.70%) > sulfamethoxazole (0.33%) > progesterone (0.14%). Environmental risk assessment calculated based on deterministic approach (the RQ method), showed no present risk from the presence of PhACs in the coastal water of Klang River estuary. Nonetheless, this baseline assessment can be used for better understanding on PhACs pollution profile and distribution in the tropical coastal and estuarine ecosystem as well as for future comparative studies.

Investigation of pharmaceutically active compounds in an urban receiving water: Occurrence, fate and environmental risk assessment.

Pharmaceutically active compounds (PhACs) recently have been recognized to constitute a health risk for aquatic ecosystems. The major pathways of PhACs to enter the aquatic environment are excretion and discharge of effluents through sewage treatment plants (STPs). The occurrence, bioaccumulation and risk assessment of lipophilic PhACs, including erythromycin, ketoconazole, indomethacin, diclofenac, gemfibrozil, bezafibrate, propranolol, carbamazepine, sertraline and 17α-ethinylestradiol were investigated in a river that receives effluents from STP. The results indicate that the PhACs were extensively existed in fish, sediment, suspended particulate matter (SPM), colloidal phase (5 kDa to 1 µm) and truly dissolved phase (< 5 kDa) water, with total concentration of ten PhACs (Σ10PhACs) of ND-19.6 ng/g, 7.3-11.2 ng/g, 25.3-101.5 ng/g, 10.1-27.7 ng/L and 67.0-107.6 ng/L, respectively. The Σ10PhACs for particulate and water samples collected from STP's outfall site were higher than those collected from upstream and downstream, indicating that the STP is an important PhACs source of river. However, the Σ10PhACs in sediment showed no significant statistical differences in the sampling area, and which was 3.5-9.5 times lower than those in SPM samples. The colloidal phase contributed 2.5-28.5% of erythromycin, 5.8-45.6% of ketoconazole, 8.4-32.2% of indomethacin, 7.0-21.4% of diclofenac, 11.6-36.9% of gemfibrozil, 10.2-45.9% of bezafibrate, 5.9-16.8% of propranolol, 1.9-11.1% of carbamazepine and 1.1-23.8% of sertraline in the aquatic environment. This suggests that aquatic particulates (e.g., colloids and SPM) maybe an important carrier for PhACs in the aquatic system. In general, the Σ10PhACs in the tissues of fish were in order as follows: kidney > brain > liver > gill > muscle. Based on truly dissolved concentrations of PhACs in the water, bioaccumulation factors were between 3.7 and 2727.3 in the fish tissues, sertraline exhibited bioaccumulation potential. In all the risk assessments, erythromycin could cause most harmful adverse health effects for the most sensitive algae group based on the acute and chronic data. In addition, the risk quotient values for diclofenac toward fish were higher than 1. These results indicate that the PhACs pose a potential risk to the aquatic organisms, especially for chronic risk.

Continuous fungal treatment of non-sterile veterinary hospital effluent: pharmaceuticals removal and microbial community assessment.

Source point treatment of effluents with a high load of pharmaceutical active compounds (PhACs), such as hospital wastewater, is a matter of discussion among the scientific community. Fungal treatments have been reported to be successful in degrading this type of pollutants and, therefore, the white-rot fungus Trametes versicolor was applied for the removal of PhACs from veterinary hospital wastewater. Sixty-six percent removal was achieved in a non-sterile batch bioreactor inoculated with T. versicolor pellets. On the other hand, the study of microbial communities by means of DGGE and phylogenetic analyses led us to identify some microbial interactions and helped us moving to a continuous process. PhAC removal efficiency achieved in the fungal treatment operated in non-sterile continuous mode was 44 % after adjusting the C/N ratio with respect to the previously calculated one for sterile treatments. Fungal and bacterial communities in the continuous bioreactors were monitored as well.

Detection of 10 commonly used pharmaceuticals in reef-building stony corals from shallow (5-12 m) and deep (30-40 m) sites in the Red Sea.

Although pharmaceutically-active compounds (PhACs) are increasingly being found to be present in marine environments, their presence in coral reefs, already under threat from various stressors, has remains unexplored. This study focused on PhAC presence in two stony-coral genera, collected from different depths and sites in the Red Sea. The findings reveal the presence of ten different PhACs, with elevated concentrations detected in corals from shallow sites and in areas with heavy human activity. Notably, all samples contained at least one PhAC, with the antibiotic sulfamethoxazole being the most prevalent compound, detected in 93% of the samples, at concentrations ranging from 1.5 to 2080 ng/g dry weight (dw) tissue, with an average concentration of 106 ng/g dw. These findings underscore the urgent need for conservation initiatives aimed at protecting coral-reef ecosystems from the escalating threat of anthropogenic contamination, including such potential risks as the development of antibiotic resistance in marine organisms and the disruption of critical spawning synchrony among coral populations.

In vitro impacts of polystyrene microplastics and environmental pollutants on ethoxyresorufin-O-deethylase and glutathione S-transferase activity in Mossambica tilapia.

Microplastic (MP) pollution is a potential threat to marine organisms. In vitro toxicity of MPs and other pollutants, such as pharmaceutically active compounds (PhACs) and brominated flame retardants (BFRs), has been understudied. This study aimed to investigate the effects of polystyrene microplastics (PS-MPs) with different particle sizes on two biomarkers: ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) in tilapia liver homogenates. The study also examined the combined effects of PS-MPs with various environmental contaminants, including three metal ions (Cu2+, Zn2+, Pb2+), three BFRs, and six PhACs. PS-MPs alone had no remarkable effects on the two biomarkers at the selected concentrations. However, PS-MPs combined with other pollutants significantly affected the two biomarkers in most situations. For EROD activity, PS + metal ions (except Zn2+ at 1000 µg/L), PS + BFRs (except decabromodiphenyl oxide (BDE-209)) or PS+ trimethoprim (TMP) significantly inhibited activity values, whereas PS+ 4-acetaminophen (AMP) induced EROD activity. For GST, PS together with most tested pollutants (except PS+ ibuprofen (IBF)) greatly decreased the activities. Accordingly, future research should focus on combined toxicity of mixtures to set more reasonable environmental safety evaluation standards.

Impact of veterinary pharmaceuticals on environment and their mitigation through microbial bioremediation.

Veterinary medications are constantly being used for the diagnosis, treatment, and prevention of diseases in livestock. However, untreated veterinary drug active compounds are interminably discharged into numerous water bodies and terrestrial ecosystems, during production procedures, improper disposal of empty containers, unused medication or animal feed, and treatment procedures. This exhaustive review describes the different pathways through which veterinary medications enter the environment, discussing the role of agricultural practices and improper disposal methods. The detrimental effects of veterinary drug compounds on aquatic and terrestrial ecosystems are elaborated with examples of specific veterinary drugs and their known impacts. This review also aims to detail the mechanisms by which microbes degrade veterinary drug compounds as well as highlighting successful case studies and recent advancements in microbe-based bioremediation. It also elaborates on microbial electrochemical technologies as an eco-friendly solution for removing pharmaceutical pollutants from wastewater. Lastly, we have summarized potential innovations and challenges in implementing bioremediation on a large scale under the section prospects and advancements in this field.

The behavior of pharmaceutically active compounds and contrast agents during wastewater treatment - Combining sampling strategies and analytical techniques: A critical review.

Increasing consumption of pharmaceuticals and the respective consequences for the aquatic environment have been the focus of many studies over the last thirty years. Various aspects in this field were investigated, considering diverse pharmaceutical groups and employing a wide range of research methodologies. Various questions from the perspectives of different research areas were devised and answered, resulting in a large mix of individual findings and conclusions. Collectively, the results of the studies offer a comprehensive overview. The large variety of methods and strategies, however, demands close attention when comparing and combining information from heterogeneous projects. This review critically examines the application of diverse sampling techniques as well as analytical methods in investigations concerning the behavior of pharmaceutically active compounds (PhACs) and contrast agents (CAs) in wastewater treatment plants (WWTPs). The combination of sampling and analysis is discussed with regard to its suitability for specific scientific problems. Different research focuses need different methods and answer different questions. An overview of studies dealing with the fate and degradation of PhACs and CAs in WWTPs is presented, discussing their strategic approaches and findings. This review includes surveys of anticancer drugs, antibiotics, analgesics and anti-inflammatory drugs, antidiabetics, beta blockers, hormonal contraceptives, lipid lowering agents, antidepressants as well as contrast agents for X-ray and magnetic resonance imaging.

Ranking of concern, based on environmental indexes, for pharmaceutical and personal care products: an application to the Spanish case.

A wide range of Pharmaceuticals and Personal Care Products (PPCPs) are present in the environment, and many of their adverse effects are unknown. The emergence of new compounds or changes in regulations have led to dynamical studies of occurrence, impact and treatment, which consider geographical areas and trends in consumption and innovation in the pharmaceutical industry. A Quantitative study of Structure-Activity Relationship ((Q)SAR) was performed to assess the possible adverse effects of ninety six PPCPs and metabolites with negligible experimental data and establish a ranking of concern, which was supported by the EPA EPI Suite™ interface. The environmental and toxicological indexes, the persistence (P), the bioaccumulation (B), the toxicity (T) (extensive) and the occurrence in Spanish aquatic environments (O) (intensive) were evaluated. The most hazardous characteristics in the largest number of compounds were generated by the P index, followed by the T and B indexes. A high number of metabolites has a concern score equal to or greater than their parent compounds. Three PBT and OPBT rankings of concern were proposed using the total and partial ranking method (supported by a Hasse diagram) by the Decision Analysis by Ranking Techniques (DART) tool, which was recently recommended by the European Commission. An analysis of the sensibility of the relative weights of these indexes has been conducted. Hormones, antidepressants (and their metabolites), blood lipid regulators and all of the personal care products considered in this study were at the highest levels of risk according to the PBT and OPBT total rankings. Furthermore, when the OPBT partial ranking was performed, X-ray contrast media, H2 blockers and some antibiotics were included at the highest level of concern. It is important to improve and incorporate useful indexes for the predicted environmental impact of PPCPs and metabolites and thus focus experimental analysis on the compounds that require urgent attention.

A new polymorph of N-(6-methylpyridin-2-yl)mesitylenesulfonamide.

A new polymorph is reported of the pharmaceutically active sulfapyridine derivative, N-(6-methylpyridin-2-yl)mesitylenesulfonamide, in the zwitterionic form 2-methyl-6-{[(2,4,6-trimethylbenzene)sulfonyl]azanidyl}pyridin-1-ium, C15H18N2O2S. The observed dimorphism is solvent dependent. The phase described previously [Beloso, Castro, García-Vázquez, Pérez-Lourido, Romero & Sousa (2003). Z. Anorg. Allg. Chem. 629, 275-284] crystallizes from ethanol and several other organic solvents, whereas the new form described here is obtained as a phase-pure product from methanol. The molecules in both dimorphic phases are very similar and adopt the conformation which is also predicted for an individual molecule by force field calculations. However, the two forms differ in their packing and hydrogen bonding. Results from solvent-assisted grinding indicate that the new form is less stable than the previously published phase.

Emerging contaminants in the northwest area of the Tai Lake Basin, China: Spatial autocorrelation analysis for source apportionment and wastewater-based epidemiological analysis.

In the present study, 60 emerging contaminants (ECs) were detected from 88 target compounds in the district of Wujin, which is the northwest area of Tai Lake Basin, China. Among them, CF (caffeine), a type of PhAC (pharmaceutically active compound), was detected as the pollutant with the highest concentration. It was observed that the removal efficiencies of PFASs (per-/polyfluoroalkyl substances) in wastewater treatment plants were lower than those of pesticides; further, those of pesticides were lower than those of PhACs. Based on the spatial agglomeration estimated by the spatial autocorrelation model, the probable sources of 28 contaminants were identified. This model provided a new perspective that would help to clarify the location of sources with high accuracy. The point sources of 6 PFASs and 14 PhACs were successfully found; in contrast, the main source of pesticides was identified as an agricultural nonpoint source. Finally, the potential risks of the ECs were also assessed in this study, including their aquatic ecological risks and human exposure risks. It was concluded that pesticides generally had the highest ecological risk, followed by PFASs and PhACs. To evaluate the population risk of pesticides, the wastewater-based epidemiological model was extended to back-calculate the per capita pesticide consumption, which was 0.22 g d-1 (103capita)-1.