Identification, quantification, and prioritization of new emerging pollutants in domestic and industrial effluents, Korea: Application of LC-HRMS based suspect and non-target screening.

The present study was designed to identify recently (or rarely) recognized or unreported substances (RRS or URS) contained in the effluents from water treatment plants in two industrialized urban areas, Gumi and Daegu, in Korea. In addition to 30 initial targets, 72 substances were identified through suspect and non-target screening (SNTS). Among them were 4 RRSs and 22 URSs, respectively. The quantitative analyses were applied to 35 pharmaceuticals, 15 pesticides, 13 poly-/perfluorinated alkyl substances (PFASs), 2 organophosphate flame retardants (OPFRs), 2 corrosion inhibitors, and 3 metabolites. The highest average concentration was observed for benzotriazole, followed by those for niflumic acid, and metformin. Effluents from Gumi mainly contained benzotriazole and metformin whereas niflumic acid and tramadol were the major components in effluents from Daegu. According to a scoring system based on risk relevant parameters, higher priorities were given to telmisartan, PFOA, and cimetidine. Yet, priorities for some substances were area specific (e.g., benzotriazole from Gumi, PFASs from Daegu), reflecting differences in industry profiles and populations. Many of the RRSs and URSs were recognized as potential hazards. The new identifications and evaluations should be taken into consideration for constant monitoring and management, as do the previously recognized contaminants.

Emerging pharmaceuticals and industrial chemicals in Nakdong River, Korea: Identification, quantitative monitoring, and prioritization.

The extensive development and use of new anthropogenic chemicals have inevitably led to their presence in aquatic environments. Surface waters affected by sewage effluents have been exposed to these new substances. In the present study, the occurrence of anthropogenic substances, including pharmaceuticals and industrial chemicals, was investigated in one of the major rivers in Korea, the Nakdong River. Furthermore, seasonal variations in their content were determined via annual monitoring. Through the suspect and non-target screening (SNTS) technique, 58 substances were newly identified in the river and integrated in the quantitative monitoring practice. The results revealed that niflumic acid and melamine exhibited the highest median concentrations, i.e., 320 ng/L and 11,000 ng/L, respectively. The results associated with seasonal change revealed that the concentration of a considerable number of substances increased in winter when the flow rate was low. Conversely, some substances exhibited high concentrations in summer (e.g., polyethylene glycol) and spring (e.g., niflumic acid). This was attributed to the seasonal changes in the consumption, prescriptions, or the application of alternative substances. These changes were also reflected by the risk quotient (RQ) values calculated from the concentration and toxicity values. Pharmaceuticals such as telmisartan and carbamazepine and industrial chemicals such as organophosphorus flame retardants (OPFRs) and melamine accounted for approximately 90% of the total RQ. Major substances prioritized using the production of the RQ value and the detection frequency included OPFRs and telmisartan. It is recommended that these results be reflected in future water quality monitoring plans.

Identification of transformation products to characterize the ability of a natural wetland to degrade synthetic organic pollutants.

Natural wetlands have been recognized as a natural reactor for degradation and elimination of environmental pollutants. The Upo Wetland, the largest inland wetland in Korea, is mainly surrounded by agricultural lands and it is susceptible to contamination from excess nutrient loads and synthetic organic contaminants (SOCs) (e.g., pesticides). The aim of this study was to identify major SOCs in the wetland and evaluate their degradation. We used high resolution mass spectrometry (HRMS) with a two-step analysis approach (i.e., 1st analysis for target measurement along with suspect and non-target screening (SNTS) and 2nd analysis for complimentary suspect screening) to identify and quantify the transformation products (TPs) of the identified parent SOCs. Quantitative analysis of 30 targets, mainly including pesticides, showed that fungicides were the major SOCs detected in the wetland, accounting for about 50% of the composition ratio of the total SOCs quantified. Orysastrobin occurred at the highest mean concentration (>700 ng/L), followed by two other fungicides, carbendazim and tricyclazole. The first analysis (SNTS) tentatively identified 39 TPs (30 by suspect, 9 by non-target screening) of 14 parent pesticides. Additionally, the second analysis (complimentary suspect screening) identified 9 more TPs. Among the 48 total TPs identified, 7 were confirmed with reference standards. The identification of the remaining TPs had a high confidence level (e.g., level 2 or 3). Regarding transport though the wetland, most TPs showed greater peak area ratios (i.e., the relative portion of chromatographic area of the TPs to the parent compound) at the outlet point of the wetland compared to the inlet point. The risk quotient, which was calculated using the concentrations of parent compounds, decreased toward the outlet, demonstrating the degradation capacity of the wetland. The estimates for biodegradability, hydrophobicity, and toxicity by an in-silico quantitative structure-activity relationship (QSAR) model indicated a lower half-life, lower logDOW, and greater effect concentration for most TPs compared to the parent compounds. Based on these results, we conclude that natural wetlands play a role as an eco-friendly reactor for degrading SOCs to form numerous TPs that are lower risk than the parent compounds.

Occurrence and Concentration of Chemical Additives in Consumer Products in Korea.

As the variety of chemicals used in consumer products (CPs) has increased, concerns about human health risk have grown accordingly. Even though restrictive guidelines and regulations have taken place to minimize the risks, human exposure to these chemicals and their eco-compatibility has remained a matter of greater scientific concern over the years. A major challenge in understanding the reality of the exposure is the lack of available information on the increasing number of ingredients and additives in the products. Even when ingredients of CPs formulations are identified on the product containers, the concentrations of the chemicals are rarely known to consumers. In the present study, an integrated target/suspect/non-target screening procedure using liquid chromatography-high resolution mass spectrometry (LC-HRMS) with stepwise identification workflow was used for the identification of known, suspect, and unknown chemicals in CPs including cosmetics, personal care products, and washing agents. The target screening was applied to identify and quantify isothiazolinones and phthalates. Among analyzed CPs, isothiazolinones and phthalates were found in 47% and in 24% of the samples, respectively. The highest concentrations were 518 mg/kg for benzisothiazolone, 7.1 mg/kg for methylisothiazolinone, 2.0 mg/kg for diethyl phthalate, and 21 mg/kg for dimethyl phthalate. Suspect and non-target analyses yielded six tentatively identified chemicals across the products including benzophenone, ricinine, iodocarb (IPBC), galaxolidone, triethanolamine, and 2-(2H-Benzotriazol-2-yl)-4, 6-bis (1-methyl-1-phenylethyl) phenol. Our results revealed that selected CPs consistently contain chemicals from multiple classes. Excessive use of these chemicals in daily life can increase the risk for human health and the environment.

Prioritization of highly exposable pharmaceuticals via a suspect/non-target screening approach: A case study for Yeongsan River, Korea.

Pharmaceuticals and personal care products (PPCPs) in the Yeongsan River, Korea were prioritized via suspect and non-target analysis using LC-HRMS (QExactive plus Orbitrap) followed by semi-quantitative analysis to confirm the priority of PPCPs. A scoring and ranking system for prioritization was suggested based on occurrence frequency and chromatographic peak area or concentration. Through suspect and non-target screening, more than 50 PPCPs were tentatively identified and ranked by the scoring system. Among them, 28 substances were finally confirmed using reference standards. For estimating concentration, 26 confirmed PPCPs and 12 additional substances not included in the first ranking were semi-quantitatively analyzed. We found that carbamazepine, metformin, paraxanthine, naproxen, and fluconazole occurred 100% of the time above the limit of quantification in 14 samples, whereas carbamazepine, metformin, paraxanthine, caffeine, and cimetidine showed maximum concentrations above 1000 ng/L. Thus, in the final prioritization list, carbamazepine, metformin, and paraxanthine shared first place, followed by caffeine, cimetidine, lidocaine, naproxen, cetirizine, climbazole, fexofenadine, tramadol, and fluconazole, with scores of 100 or above. We suggest that these 12 PPCPs are the most highly exposable substances, and thus must be considered in future water monitoring in the Yeongsan River.