Effectiveness of lumbar motion style acupuncture treatment on inpatients with acute low back pain: A pragmatic, randomized controlled trial

BACKGROUND AND PURPOSE

This parallel, single-center, pragmatic, randomized controlled study aimed to investigate the effectiveness and safety of motion style acupuncture treatment (MSAT; a combination of acupuncture and Doin therapy) to reduce pain and improve the functional disability of patients with acute low back pain (aLBP) due to road traffic accidents.

MATERIALS AND METHODS

Ninety-six patients with aLBP admitted to the Haeundae Jaseng Hospital of Korean Medicine in South Korea due to traffic accidents were treated with integrative Korean medicine (IKM) with additional 3-day MSAT sessions during hospitalization (MSAT group, 48 patients) or without (control group, 48 patients), and followed up for 90 days.

RESULTS

The mean numeric rating scale (NRS) scores of low back pain (LBP) of the MSAT and control groups were both 6.7 (95% confidence interval [CI]: 6.3, 7.1) at baseline. After completing the third round of all applicable treatment sessions (the primary endpoint in this study), the mean NRS scores of the MSAT and control groups were 3.76 (95% CI: 3.54, 3.99) and 5.32 (95% CI: 5.09, 5.55), respectively. The difference in the mean NRS score between the two groups was 1.56 (95% CI: 1.25, 1.87).

CONCLUSION

IKM treatment combined with MSAT can reduce pain and improve the range of motion of patients with aLBP.

TRIAL REGISTRATION

This trial is registered at ClinicalTrial.gov (NCT04956458).

Long-Term Follow-Up of Inpatients with Rotator Cuff Tear Who Received Integrative Korean Medicine Treatment: A Retrospective Analysis and Questionnaire Survey

CONTEXT

Rotator cuff tear is one of the most common causes of shoulder pain and has become a prominent disease most frequently treated by surgery.

OBJECTIVES

To investigate the long-term therapeutic effect of integrative Korean medicine (KM) as a conservative treatment in treating rotator cuff tears.

DESIGN

A multicenter observational study.

SETTINGS

The settings involve four regional network KM hospitals.

PATIENTS

The study participants are 288 patients aged 19-70 with rotator cuff tear identified by radiologist based on magnetic resonance imaging who received integrative KM treatment for the chief complaint of shoulder pain between 1 January 2015 and 31 March 2020.

INTERVENTION

None.

MAIN OUTCOMES

The primary outcome was the pain score in the affected shoulder, measured by the numeric rating scale (NRS). The secondary outcomes were Shoulder Pain and Disability Index (SPADI), 5-Level Quality of life: EuroQol 5-Dimension (EQ-5D-5L), Patient Global Impression of Change (PGIC), and range of motion (ROM) scores.

RESULTS

Eligible patients for MCID achievement analysis for minimally clinical important change were 167, and 109 completed the follow-up survey. The mean NRS pain score in the affected shoulder was 5.80 ± 1.27 at admission, 3.50 ± 1.32 at discharge, and 3.83 ± 2.04 at follow-up.The mean SPADI score was 51.48 ± 20.18 at admission, 37.76 ± 19.23 at discharge, and 24.26 ± 21.80 at follow-up. The improvement at discharge (P-value < 0.001) and follow-up (P-value < 0.001) compared to those at admission was statistically significant. The results also presented a significant improvement in ROM for all motions at discharge after treatment (P-value < 0.001). The number of patients who achieved minimal clinically important difference in NRS was 116 (69.5%) at discharge and 71 (65.1%) at follow-up, and in SPADI was 82 (50.9%) at discharge and 77 (70.6%) at follow-up.

CONCLUSION

The results of this study suggested that integrative KM treatment can help improve pain, functional impairment, QoL, and ROM in patients with a rotator cuff tear TRIAL REGISTRATION: NCT04566939.

Effectiveness of motion style acupuncture treatment for patients with shoulder disorders: A prospective observational study

CONTEXT

Shoulder disorders impair the ability to work. In most cases, the primary symptoms caused by shoulder disorders consist of pain and limitations in the range of motion.

OBJECTIVES

This study aimed to investigate the efficacy of motion style acupuncture treatment (MSAT), a conservative treatment modality for shoulder disorders.

DESIGN

prospective observational study SETTING: A Korean Medicine hospital PATIENTS: Eighty outpatients with shoulder disorders INTERVENTION: Either MSAT with integrative Korean medicine treatment (MSAT group; n = 40) or integrative Korean medicine treatment only (control group; n = 40).

OUTCOME MEASURES

The primary outcome was the shoulder range of motion (ROM), and the secondary outcomes were the numeric rating scale (NRS), visual analog scale (VAS), shoulder pain and disability index (SPADI), and 5-level EuroQol 5-dimension (EQ-5D-5L) scores.

RESULTS

At the primary endpoint (2 weeks from the start of the treatment), the MSAT group showed statistically significantly larger ROM for all motions, except adduction ROM, compared to the control group [Flexion ROM (165.10±4.14 vs. 150.49±4.06; P<0.001), extension ROM (43.24±1.55 vs. 40.56±1.51; P<0.05), abduction ROM (160.92±5.68 vs. 134.95±5.54; P<0.001), internal rotation ROM (73.38±2.96 vs. 65.00±2.89; P<0.001), and external rotation ROM (73.78±3.61 vs. 65.88±3.50; P<0.01)]. Additionally, the MSAT group showed significantly lower NRS, SPADI scores at week 2 than the control group; this trend was maintained until the 3-month follow-up.

Body distribution and ecotoxicological effect of nanoplastics in freshwater fish, Zacco platypus

The increased consumption of plastics worldwide, has led to the emergence of nanoplastics as important environmental pollutants. Despite the presence of nanoplastics in aquatic environments, their effects on ecosystems remain largely unexplored due to the analysis complexity. This study investigated the organ accumulation and toxic effects of 50 nm polystyrene nanoplastics (PS-NPs) in Zacco platypus (Z. platypus; also known as pale chub fish) using pyrolyzer-gas chromatography-mass spectrometry (Pyr-GC/MS). PS-NPs accumulated in Z. platypus' brain, digestive tract, branchia, and liver, causing changes at cellular level. Over a 14-day exposure, the accumulated PS-NPs led to observable changes in fish behavior (e.g., Total traveled distance and maximum velocity). In addition, the oxidative stress in each organ of Z. platypus increased as the exposure concentration of PS-NPs increased. This study shows that accumulation of nanoplastics in fish, resulting in behavioral changes and biochemical toxicity. As the pattern of change magnifies with exposure time and concentration, from a long-term perspective, the influence of nanoplastics on aquatic ecosystems become evident. This underscores the urgency for continuous research into the potential risks of nanoplastics in aquatic ecosystems.

Distribution and transformation of organophosphate esters in moving bed biofilm reactor

A moving bed biofilm reactor (MBBR) process in wastewater treatment plants (WWTPs) uses plastic carriers, called biofilm carrier, to increase their treatment efficiency. Biofilm carrier is made up of plastic, containing the OPEs as flame retardants or plasticizers, so OPEs in biofilm carrier are possible to release from WWTPs to the river. This study investigated the effect of the MBBR process in WWTP on aquatic environments, focusing on OPEs. OPE eluted from the biofilm carrier by leaching test was tris(2-chloroethyl) phosphate (TCEP), and the concentration of the effluent compared to the influent was increased in the WWTP of the MBBR process. 3609 mg/day of TCEP would be discharged into the water using the second-order model with rate constant [Formula: see text] = 0.000451 (ng L-1)-1 h-1, which is the most suitable for the leaching concentration of TCEP. It was identified that TCEP in biofilm carrier was transformed into oxidative dechlorinated compounds and oxidative compounds by microorganisms in the bioreactor. As a result of the study, it was confirmed that not only TCEP but also transformation products of TCEP emitted into the water from the MBBR process of WWTP.

Risk assessment of bisphenol analogues towards mortality, heart rate and stress-mediated gene expression in cladocerans Moina micrura

Bisphenol A (BPA) is a well-known endocrine-disrupting compound that causes several toxic effects on human and aquatic organisms. The restriction of BPA in several applications has increased the substituted toxic chemicals such as bisphenol F (BPF) and bisphenol S (BPS). A native tropical freshwater cladoceran, Moina micrura, was used as a bioindicator to assess the adverse effects of bisphenol analogues at molecular, organ, individual and population levels. Bisphenol analogues significantly upregulated the expressions of stress-related genes, which are the haemoglobin and glutathione S-transferase genes, but the sex determination genes such as doublesex and juvenile hormone analogue genes were not significantly different. The results show that bisphenol analogues affect the heart rate and mortality rate of M. micrura. The 48-h lethal concentration (LC₅₀) values based on acute toxicity for BPA, BPF and BPS were 611.6 µg L^-1, 632.0 µg L^-1 and 819.1 µg L^-1, respectively. The order of toxicity based on the LC₅₀ and predictive non-effect concentration values were as follows: BPA > BPF > BPS. Furthermore, the incorporated method combining the responses throughout the organisation levels can comprehensively interpret the toxic effects of bisphenol analogues, thus providing further understanding of the toxicity mechanisms. Moreover, the output of this study produces a comprehensive ecotoxicity assessment, which provides insights for the legislators regarding exposure management and mitigation of bisphenol analogues in riverine ecosystems.

De Novo Transcriptomic and Life-History Responses of Moina Micrura Under Stress Environment Conditions

Moina micrura represents a promising model species for ecological and ecotoxicological investigations in tropical freshwater ecosystems. Illumina NovaSeq™ 6000 sequencing was employed in this study to analyze M. micrura across three distinct developmental stages: juvenile, adult, and male. Current study successfully annotated 51,547 unigenes (73.11%) derived from seven (7) different databases. A total of 554 genes were found to be significantly upregulated, while 452 genes showed significant downregulation between juvenile and male. Moreover, 1001 genes were upregulated, whereas 830 genes exhibited downregulation between the adult and male. Analysis of differentially expressed genes revealed upregulation of chitin, cuticle, myosin (MYO), mitogen-activated protein kinases (MAPK), fibrillin (FBN), cytochrome (CYP), glutathione s-transferase (GST), vitellogenin (VTG), acetylcholinesterase (AChE), and transforming growth factor beta (TGFB) under unfavorable environmental conditions (male), as compared to favorable environmental conditions (juveniles and adults). These alterations in gene expression significantly impact the phenological and life-history traits of M. micrura. Furthermore, the upregulation of hemoglobin (HMB), doublesex (DSX), juvenile hormone analogs (JHA), heat shock protein (HSP), and methyltransferase (METT) genes in males initiates the sex-switching effects observed in M. micrura. These findings hold substantial value for researchers interested in determining M. micrura sequences for future investigations of gene expression and comparative reproductive genome analysis within the Moina genus and cladoceran families.

Prioritization of pharmaceuticals and personal care products in the surface waters of Korea: Application of an optimized risk-based methods

The occurrence of PPCPs in aquatic environments and their potential adverse effects on aquatic organisms have raised worldwide concerns. To address this issue, a study was conducted to analyze 137 selected PPCPs in Korean surface waters, and an optimized risk-based prioritization was performed. The results revealed that 120 PPCPs were detected, with 98 quantified at concentrations ranging from few ng/L to 42,733 ng/L for metformin. The 95% upper confidence limit (UCL95) of the mean value of the measured environmental concentration (MEC) for Metformin was about eight times higher than the second highest compound, dimethyl phthalate, indicating that antidiabetic groups had the highest concentration among the therapeutic groups. An optimized risk-based prioritization was then assessed based on the multiplication of two indicators, the Frequency of Exceedance and the Extent of Exceedance of Predicted No-Effect Concentrations (PNECs), which can be calculated using the traditional risk quotient (RQ) approach. The study found that clotrimazole had the highest risk quotient value of 17.4, indicating a high risk to aquatic organisms, with seven and 13 compounds showing RQ values above 1 and 0.1, respectively. After considering the frequency of exceedance, clotrimazole still had the highest novel risk quotient (RQ_f) value of 17.4, with 99.6% of its MECs exceeding PNECs. However, the number of compounds with RQ_f values above 1 decreased from seven to five, with cetirizine and flubendazole being excluded. Furthermore, only 10 compounds exhibited RQ_f values above 0.1. The study also observed significant differences in the results between risk-based and exposure-based prioritization methods, with only five compounds, cetirizine, olmesartan, climbazole, sulfapyridine, and imidacloprid, identified in both methods. This finding highlights the importance of considering multiple methods for prioritizing chemicals, as different approaches may yield different results.

Acute toxicity and risk assessment of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) in tropical cladocerans Moina micrura

Per- and polyfluoroalkyl substances (PFAS) are gaining worldwide attention because of their toxicity, bioaccumulative and resistance to biological degradation in the environment. PFAS can be categorised into endocrine disrupting chemicals (EDCs) and identified as possible carcinogenic agents for the aquatic ecosystem and humans. Despite this, only a few studies have been conducted on the aquatic toxicity of PFAS, particularly in invertebrate species such as zooplankton. This study evaluated the acute toxicity of two main PFAS, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), by using freshwater cladocerans (Moina micrura) as bioindicators. This study aimed to assess the adverse effects at different levels of organisations such as organ (heart size and heart rate), individual (individual size and mortality) and population (lethal concentration, LC₅₀). PFOA was shown to be more hazardous than PFOS, with the LC₅₀ values (confidence interval) of 474.7 (350.4-644.5) μg L^-1 and 549.6 (407.2-743.9) μg L^-1, respectively. As the concentrations of PFOS and PFOA increased, there were declines in individual size and heart rate as compared to the control group. The values of PNECs acquired by using the AF method (PNEC_AF) for PFOA and PFOS were 0.4747 and 0.5496 μg L^-1, respectively. Meanwhile, the PNEC values obtained using the SSD method (PNEC_SSD) were 1077.0 μg L^-1 (PFOA) and 172.5 μg L^-1 (PFOS). PNEC_AF is more protective and conservative compared to PNEC_SSD. The findings of this study have significant implications for PFOS and PFOA risk assessment in aquatic environments. Thus, it will aid freshwater sustainability and safeguard the human dependency on water resources.

Chemical accidents in freshwater: Development of forecasting system for drinking water resources

Chemical accidents have threatened drinking water safety and aquatic systems when hazardous chemicals flow into inland waterbodies through pipelines in industrial complexes. In this study, a forecasting system was developed for the prevention of drinking water resource pollution by considering chemical transport/fate through both pipelines and river channels. To this end, we coupled a pipe network model (Storm Water Management Model) with a calibrated hydrodynamic model (Environmental Fluid Dynamics Code). In addition, we investigated whether chemical transport through pipelines would make a difference in chemical concentration predictions. For both pipelines and river channels, the results showed lower peak concentrations than those without pipelines, whereas the time of peak concentration did not change significantly. When chemicals were transported with both pipelines and river channels, the peak concentrations were 25.81% and 41.91% lower than those of chemicals carried directly into the Han and Geum Rivers without the pipeline transport. Further, our system is automated from scenario generation to analysis and usage is straightforward, with a simple input of accident information. The results of this study can be utilized to establish a safe water supply system and preliminary countermeasures against accidental water pollution in the future.

Assessment of RNA extraction protocols from cladocerans

The usage of cladocerans as non-model organisms in ecotoxicological and risk assessment studies has intensified in recent years due to their ecological importance in aquatic ecosystems. The molecular assessment such as gene expression analysis has been introduced in ecotoxicological and risk assessment to link the expression of specific genes to a biological process in the cladocerans. The validity and accuracy of gene expression analysis depends on the quantity, quality and integrity of extracted ribonucleic acid (RNA) of the sample. However, the standard methods of RNA extraction from the cladocerans are still lacking. This study evaluates the extraction of RNA from tropical freshwater cladocerans Moina micrura using two methods: the phenol-chloroform extraction method (QIAzol) and a column-based kit (Qiagen Micro Kit). Glycogen was introduced in both approaches to enhance the recovery of extracted RNA and the extracted RNA was characterised using spectrophotometric analysis (NanoDrop), capillary electrophoresis (Bioanalyzer). Then, the extracted RNA was analysed with reverse transcription polymerase chain reaction (RT-PCR) to validate the RNA extraction method towards downstream gene expression analysis. The results indicate that the column-based kit is most suitable for the extraction of RNA from M. micrura, with the quantity (RNA concentration = 26.90 ± 6.89 ng/μl), quality (A260:230 = 1.95 ± 0.15, A280:230 = 1.85 ± 0.09) and integrity (RNA integrity number, RIN = 7.20 ± 0.16). The RT-PCR analysis shows that the method successfully amplified both alpha tubulin and actin gene at 33-35 cycles (i.e. Ct = 32.64 to 33.48). The results demonstrate that the addition of glycogen is only suitable for the phenol-chloroform extraction method. RNA extraction with high and comprehensive quality control assessment will increase the accuracy and reliability of downstream gene expression, thus providing more ecotoxicological data at the molecular biological level on other freshwater zooplankton species.

Organophosphate esters in Great Lakes fish: An improved analysis to assess concentrations and human exposure via consumption

Organophosphate esters (OPEs) are flame retardant and plasticizer chemicals added to electronics, furniture, textiles, and other building materials and consumer products. In this study, fillets of fish often caught by anglers in the North American Great Lakes, Lake Trout (Salvelinus namaycush) across four Great Lakes and nearshore fish species near the large urban and industrial centers of Toronto and Hamilton, Canada, were analyzed for 22 OPEs. A rapid microextraction of homogenized tissues with methanol dramatically reduced preparation and sample handling time while achieving recoveries of 69-141%, and the optimized liquid chromatographic separation improved isomeric separations, including aryl-OPEs. Twelve of the 22 OPEs were detected, with frequencies of detection ranging from 8.3% to 98%, and five compounds were detected in >50% of the fish. The average ± standard deviation for the sum of 12 OPEs (ΣOPE₁₂) ranged from 9.6 ± 0.9 (L. Erie 2017) to 74 ± 44 (L. Superior 2001) ng/g wet weight in Lake Trout, and 12 ± 2.7 to 35 ± 30 ng/g wet weight in nearshore fish species from the Toronto and Hamilton areas. The aryl-OPEs were dominant in Lake Trout, comprising 32-77% of total ΣOPE₁₂ concentrations. In nearshore fish, the OPE patterns reflected the relative degree of exposure to run-off and wastewater inputs in the sampled receiving environments. The intake of OPEs via human consumption of Great Lakes Lake Trout and nearshore fish was estimated to range 6.5-31 ng/kg body weight/day, which is approximately 1-2 orders of magnitude lower than exposures via indoor air and ingestion/inhalation of dusts, and 3 orders of magnitude lower than estimated reference doses. The inclusion of additional OPE analytes enabled patterns of exposure and accumulation to be distinguished in fish of different species and location, and were related to source and food web influences.

Identification of biotransformation products of organophosphate ester from various aquatic species by suspect and non-target screening approach

Organic pollutants that are introduced into the aquatic ecosystem can transform by various mechanisms. Biotransformation is an important process for predicting the remaining structures of pollutants in the ecosystem, and their toxicity. This study focused on triphenyl phosphate (TPHP), which is a commonly used organophosphate flame retardant and plasticizer. Since TPHP is particularly toxic to aquatic organisms, it is essential to understand its biotransformation in the aquatic environment. In the aquatic ecosystem, based on consideration of the producer-consumer-decomposer relationship, the biotransformation products of TPHP were identified, and their toxicity was predicted. Liquid chromatography-high resolution mass spectrometry was used for target, suspect, and non-target analysis. The obtained biotransformation products were estimated for toxicity based on the prediction model. As a result, 29 kinds of TPHP biotransformation products were identified in the aquatic ecosystem. Diphenyl phosphate was detected as a common biotransformation product through a hydrolysis reaction. In addition, products were identified by the biotransformation mechanisms of green algae, daphnid, fish, and microorganism. Most of the biotransformation products were observed to be less toxic than the parent compound due to detoxification except some products (hydroquinone, beta-lyase products, palmitoyl/stearyl conjugated products). Since various species exist in a close relationship with each other in an ecosystem, an integrated approach for not only single species but also various connected species is essential.

Identification and Toxicity Prediction of Biotransformation Molecules of Organophosphate Flame Retardants by Microbial Reactions in a Wastewater Treatment Plant

Organophosphate flame retardants (OPFRs) are substances added to plastics, textiles, and furniture, and are used as alternatives to brominated flame retardants. As the use of OPFRs increases in the manufacturing industry, the concentration in the aquatic environment is also increasing. In this study, OPFRs introduced into a wastewater treatment plant (WWTP) were identified, and the toxicity of biotransformation molecules generated by the biological reaction was predicted. Tris(2-butoxyethyl) phosphate, tris(2-butoxyethyl) phosphate, and triphenyl phosphate were selected as research analytes. Chemicals were analyzed using high-resolution mass spectrometry, and toxicity was predicted according to the structure. As a result, tris(1-chloro-2-propyl) phosphate showed the highest concentration, and the removal rate of OPFRs in the WWTP was 0–57%. A total of 15 biotransformation products were produced by microorganisms in the WWTP. Most of the biotransformation products were predicted to be less toxic than the parent compound, but some were highly toxic. These biotransformation products, as well as OPFRs, could flow into the water from the WWTP and affect the aquatic ecosystem.

Long-Term Follow-Up of Inpatients with Failed Back Surgery Syndrome Who Received Integrative Korean Medicine Treatment: A Retrospective Analysis and Questionnaire Survey Study

Introduction: this study aimed to investigate the long-term clinical efficacy and satisfaction degree of integrative Korean medicine (KM) treatment for patients with failed back surgery syndrome (FBSS). Methods: we performed a follow-up questionnaire survey and retrospective analysis of medical records for patients with FBSS who underwent inpatient treatment for ≥ 1 week. The primary evaluation indices were numeric rating scale (NRS) scores for low back pain (LBP) and leg pain at admission and discharge. Sub-evaluation indices included the Oswestry Disability Index (ODI) and EuroQol 5-dimension (EQ-5D) score. The follow-up questionnaire survey obtained information regarding previous surgeries; reasons for satisfaction/dissatisfaction with surgical and KM treatment; and current status. Results: compared with at admission, there was a significant post-treatment decrease in the NRS scores for LBP and leg pain, as well as the ODI score. Further, there was a significant post-treatment increase in the EQ-5D score. Regarding the patients’ global impression of change for KM treatment administered during admission and at the follow-up questionnaire survey, 101 (95.3%) patients selected “minimally improved” or better. Conclusion: integrative KM treatment could effectively reduce pain, as well as improve function and health-related quality of life, in patients with FBSS.

Coupling of the AQUATOX and EFDC Models for Ecological Impact Assessment of Chemical Spill Scenarios in the Jeonju River, Korea

In this study, an ecological impact was assessed for the short-term leak scenario through the AQUATOX-EFDC model, which combines the proven ecological model AQUATOX with the hydrodynamic model EFDC. A case study of the coupled AQUATOX-EFDC model was conducted for 30-30,000 kg toluene leak scenarios in the Jeonju River in South Korea. A 21-day scenario simulation was conducted, and the impact of the toluene spill accident was evaluated by comparing the biomass between the control simulation and the perturbed simulation. As a result of the simulation, it was found that in the scenario in which 3000 kg of toluene was leaked for a day, a substantial change was expected in the range of 0-640 m from the accident site. Additionally, for a 30,000 kg leak, a substantial change was expected in the range of 0-2300 m from the accident site, and the greatest damage was observed for the fish species group, the top predators. As a result, the AQUATOX-EFDC simulation showed a significant ecological impact, and the proposed model will be helpful to understand the ecological impact and establish the management strategy for the ecological risk of the chemical spill.

Application of various cytotoxic endpoints for the toxicity prioritization of fine dust (PM2.5) sources using a multi-criteria decision-making approach

Fine dust (PM2.5) is generated from various sources, and many studies have reported on the sources of PM2.5. However, the current research on PM2.5 toxicity based on its sources is insufficient. In this study, we developed a framework for the prioritization of fine dust (PM2.5) sources on the basis of the multi-endpoint toxicities using the multi-criteria decision-making method (MCDM). To obtain the multi-endpoint toxicities of PM2.5 sources, cell mortality, reactive oxygen species (ROS), inflammation and mutagenicity were measured for diesel exhaust particles (DEP), gasoline exhaust particles (GEP), rice straw burning particles (RBP), coal combustion particles (CCP) and tunnel dust particles (TDP). The integrative toxicity score (ITS) of the PM2.5 source was calculated using MCDM, which consist of four steps: (1) defining the decision-making matrix, (2) normalization and weighting, (3) calculating the ITS (linear aggregation) and (4) a global sensitivity analysis. The indicator of cell mortality had the highest weight (0.3780) followed by inflammation (0.2471), ROS (0.2178) and mutagenicity (0.1571). Additionally, the ITS based on the sources contributing to PM2.5 resulted in the following order: DEP (0.89), GEP (0.44), RBP (0.40), CCP (0.23) and TDP (0.06). The relative toxicity index (RTI), which represents the ratio of toxicity due to the difference in sources, increases as the contribution of the highly toxic sources increases. The RTI over 1 is closely associated with an increased contribution from highly toxic sources, such as diesel exhaust, gasoline exhaust and biomass burning. It is necessary to investigate the toxicity of various PM2.5 sources and PM2.5 risk based on the sources.

Characterizing biotransformation products and pathways of the flame retardant triphenyl phosphate in Daphnia magna using non-target screening

Triphenyl phosphate (TPHP), one of the organophosphate flame retardants, has been widely used in manufacturing, thereby causing a gradual increase in TPHP concentrations in aquatic environments. However, the information on the biotransformation mechanism of TPHP in invertebrates is lacking. The study identified the biotransformation products of TPHP in Daphnia magna, which showed particularly high toxicity in aquatic organisms, and determined the rates of depuration. Daphnia magna, a standard species for toxicity studies, was exposed to triphenyl phosphate and transferred to the pure medium. The biotransformation products of TPHP and its depuration rates were determined by liquid chromatography-high resolution mass spectrometry. Nine biotransformation products (five in the positive mode and four in the negative mode) of triphenyl phosphate were identified in D. magna. Based on the depuration ratio, the major biotransformation mechanism is estimated to be cysteine conjugation and sulfation. Certain biotransformation products (diphenyl phosphate, hydroxylated triphenyl phosphate, and thiol triphenyl phosphate) might induce toxicity in biota. The results could be used to predict main biotransformation processes and toxic products of organophosphate flame retardants in aquatic invertebrates.

Characteristics and health effects of PM2.5 emissions from various sources in Gwangju, South Korea

Increasing evidence suggests that the toxicity of fine dust particles (PM_2.5) is linked to specific components rather than their mass. However, research on the chemical composition and health risk of PM_2.5 is insufficient. This study analyzed the metals, polycyclic aromatic hydrocarbon (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) present in PM_2.5 and evaluated their risk to health during outdoor activities. The concentration of metals was one order of magnitude higher than that of PAHs and the concentration and detection frequency of OCPs and PCBs were considerably lower than those of metals and PAHs. The lifetime excess cancer risk (LECR) for carcinogens in PM_2.5 exceeded de minimis risk (1 × 10^-6) as 1.33-3.44 × 10^-6 (at 5th-95th percentile) as Cr(VI), As, and Cd showed high contributions. Children in the 2 < years <18 age group had a high risk of cancer due to early-life susceptibility. The proportion of ∑Metals to LECR was approximately 95%, while ∑PAHs attributed to 5% of total LECR. The effects of ∑OCPs and 2,3',4,4',5'-Pentachlorobiphenyl (PCB-123) on LECR were negligible. The hazard quotient (HQ) for non-carcinogens was <1, and non-carcinogenic effects were not expected. Mn, BaP, Pb, As, and Cd were the key determinants of the HQ values and among the identified PM_2.5 sources they are closely related to industrial activities, oil combustion, and gasoline exhaust. Therefore, control strategies for these sources can effectively reduce PM_2.5 risk. This study measured the concentrations of toxic compounds in ambient PM_2.5 and considered only PM_2.5 exposure during outdoor activities. PM_2.5 health risk during the entire day would be higher than the PM_2.5 risk determined in this study, and further research is required for this evaluating this risk.

Prediction of Cd toxicity to Daphnia magna in the mixture of multi-walled carbon nanotubes and kaolinite

In this study, we investigated cadmium toxicity created by adsorption kinetics in several mixtures containing two types of multi-walled carbon nanotubes (COOH-MWCNT and NH₂-MWCNT) and natural kaolinite. Characteristics of two types of MWCNTs were measured by zeta potential and ATR FT-IR graphs and TEM images. The solution of CNTs and kaolinite was tested to study Cd adsorption kinetics and mechanisms of differentiation-associated toxicity using Daphnia magna in a binary system (Cd-MWCNTs and Cd-kaolinite) and a ternary system (Cd-MWCNTs-kaolinite). In the binary system, Cd removal efficiency was nearly 100% and 40% for MWCNTs and kaolinite because of surface charge, respectively, with increasing sorbent concentration. In the ternary system, the trend of adsorption rate was similar to that of binary system. In comparison with percent mortality in the binary system, the solution in the ternary system showed higher toxicity due to the interaction of MWCNTs-kaolinite coagulated particles, thereby decreasing Cd adsorption onto CNTs and kaolinites. Overall, kaolinite can affect the adsorption process of Cd on MWCNTs in negative ways, depending on adsorption state. In conclusion, our studies suggest that kaolinite differs with adsorption ability of Cd by MWCNTs, and toxicity is likely to be produced by multivariable regression in the adsorption state.

Cytotoxicity induced by the mixture components of nickel and poly aromatic hydrocarbons

Although particulate matter (PM) is composed of various chemicals, investigations regarding the toxicity that results from mixing the substances in PM are insufficient. In this study, the effects of low levels of three PAHs (benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene) on Ni toxicity were investigated to assess the combined effect of Ni-PAHs on the environment. We compared the difference in cell mortality and total glutathione (tGSH) reduction between single Ni and Ni-PAHs co-exposure using A549 (human alveolar carcinoma). In addition, we measured the change in Ni solubility in chloroform that was triggered by PAHs to confirm the existence of cation-π interactions between Ni and PAHs. In the single Ni exposure, the dose-response curve of cell mortality and tGSH reduction were very similar, indicating that cell death was mediated by the oxidative stress. However, 10 μM PAHs induced a depleted tGSH reduction compared to single Ni without a change in cell mortality. The solubility of Ni in chloroform was greatly enhanced by the addition of benz[a]anthracene, which demonstrates the cation-π interactions between Ni and PAHs. Ni-PAH complexes can change the toxicity mechanisms of Ni from oxidative stress to others due to the reduction of Ni²⁺ bioavailability and the accumulation of Ni-PAH complexes on cell membranes. The abundant PAHs contained in PM have strong potential to interact with metals, which can affect the toxicity of the metal. Therefore, the mixture toxicity and interactions between diverse metals and PAHs in PM should be investigated in the future.

Differential toxicities of fine particulate matters from various sources

Fine particulate matters less than 2.5 µm (PM2.5) in the ambient atmosphere are strongly associated with adverse health effects. However, it is unlikely that all fine particles are equally toxic in view of their different sizes and chemical components. Toxicity of fine particles produced from various combustion sources (diesel engine, gasoline engine, biomass burning (rice straw and pine stem burning), and coal combustion) and non-combustion sources (road dust including sea spray aerosols, ammonium sulfate, ammonium nitrate, and secondary organic aerosols (SOA)), which are known major sources of PM2.5, was determined. Multiple biological and chemical endpoints were integrated for various source-specific aerosols to derive toxicity scores for particles originating from different sources. The highest toxicity score was obtained for diesel engine exhaust particles, followed by gasoline engine exhaust particles, biomass burning particles, coal combustion particles, and road dust, suggesting that traffic plays the most critical role in enhancing the toxic effects of fine particles. The toxicity ranking of fine particles produced from various sources can be used to better understand the adverse health effects caused by different fine particle types in the ambient atmosphere, and to provide practical management of fine particles beyond what can be achieved only using PM mass which is the current regulation standard.