Temporal groundwater quality, health risks and source point management zonation of multi-aquifers in Jilin Qian'an, Northeastern China.

Jilin Qian'an, located in Northeastern China's Songnen Plain, relies almost exclusively on groundwater for drinking. The quaternary phreatic aquifer (Q3) is distinguished by high geogenic fluoride and arsenic concentrations, which necessitates reliance on quaternary confined (Q1) and neogene confined (N) aquifers (deeper aquifers) as source point management (SPM) alternatives. However, deeper aquifers are contaminated, necessitating temporal monitoring and unique management strategies. Using 165 samples, this study investigated the appropriateness of deeper restricted aquifers as a continuous SPM alternative by assessing the spatiotemporal groundwater quality and human health risk of the multi-aquifers in Jilin Qian'an from the 1980s to the 2010s. In addition, a source point management zonation (SPMZ) was implemented to define the specific intervention necessary in various portions of the study area. Results indicate water quality parameters were within recommended limits for most samples except fluoride, while arsenic was the most significant heavy metal pollutant. Mean groundwater mineralization in all the aquifers increased with time. Deeper aquifers are still a better alternative to the shallow phreatic aquifer as groundwater quality in the study is of the order N > Q1 > Q3 in the respective aquifers. Cancer risk assessment (CR) shows increases from 2001 to the 2010s in all aquifers except in Q3. SPMZ delineated: High As and high F zones; high As and low F zones; high As zones; high F zones; low F zones; and safe zones. Localized intervention based on SPMZ is recommended, along with the use of alternative water sources.

Response of groundwater chemical characteristics to land use types and health risk assessment of nitrate in semi-arid areas: A case study of Shuangliao City, Northeast China.

Groundwater is an important source of water, especially in semi-arid areas. The assessment of the chemical characteristics of groundwater under different land use types the associated risk to human health is of important significance for water resources utilization and protecting the ecological environment. The present study analyzed the hydrochemical characteristics and ion sources of groundwater, taking Shuangliao City as an example. The analysis was based on the field investigation (82 water samples), descriptive statistics, correlation analysis, ion proportionality coefficient method, and principal component analysis (PCA). The results indicated that the concentrations of most ions in the aquifer had wide spatiotemporal variation and were susceptible to environmental influences. NO3- showed the highest spatial variability, with concentrations ranging from 0.0 to 529.48 mg·L-1. The processes contributing the most to the chemical composition of groundwater were leaching/dissolution and cation exchange. The spatial distribution of groundwater chemistry types was visually obtained through the combined use of Piper trilinear charts and a Digital Terrain Model (DTM). The HCO3-Ca type dominated. Groundwater Cl-, SO42-, and Ca2+ were negatively correlated with the Normalized Difference Vegetation Index (NDVI) due to the absorption of inorganic salt by vegetation roots, indicating that land use types affect groundwater hydrochemistry in the area. The hazard quotient (HQ) used in the human health risk assessment (HHRA) model indicated children (0.0010-6.4162) to be at the highest risk, followed by adult females (0.0007-4.0396), with adult males (0.0005-3.0863) under the lowest risk. The spatial distribution of groundwater nitrate was shown to pose risks to children, adult females, and adult males across 62.97%, 50.01%, and 39.34% of the study area, respectively. This study can improve the understanding of groundwater evolution and the relationship between water chemistry and land use types. This study can also guide the development and utilization of groundwater resources and conservation of water quality in semi-arid areas.

Hydrochemical characteristics and identification of pollution ions of the springs in the south of Yanbian City, China.

Mathematical statistics, correlation analysis, Piper and Gibbs diagrams, and geographic information system- based multi-criteria decision analysis were used to study the hydrochemical characteristics and identification of hydrochemical ions affected by human activities of the springs in the south of Yanbian City, China. Four criteria were selected: land use/land cover, village density, distance to towns, and distance to main roads. The improved entropy method was used to assign weight to each criterion, followed by evaluating the human activities impact index map, which was used to extract the human activities impact index of springs. The correlation coefficient was calculated to identify the hydrochemical parameters affected by human activities. The results show that the main hydrochemical parameters are Ca2+ among cations and HCO3- among anions. Ca2+, Mg2+, HCO3-, Cl-, and total dissolved solids (TDS) have a strong correlation and similar spatial distribution, showing a decreasing trend from northwest to southeast. Most hydrochemical parameters show a similar spatial distribution trend. The hydrochemical types of springs are HCO3-Ca, HCO3-Ca•Mg, HCO3-Na•Ca, and HCO3-Ca. In the study area, Na+, K+, TFe, Mn2+, F-, PO43-, and oxygen consumption are negligibly affected by human activities, Mg2+, HCO3-, and Cl- were slightly affected, and TDS and total hardness (TH) were strongly affected. With a correlation coefficient of 0.913, nitrate exhibited the highest correlation with the human activities impact index; it was significantly affected by human activities. We conclude that nitrate was the most affected by human activities, followed by TH, TDS, and other hydrochemical parameters.

Research on the exploitation and utilization degree of mineral water based on ecological base flow in the Changbai Mountain basalt area, northeast China.

Mineral water from the Changbai Mountain basalt area is China's most important source of drinking water. Mineral water with abundant output and enriched trace elements has driven the rapid development of the local economy. However, the extensive exploitation of mineral water and the neglect of ecological base flows threaten interdependent river ecosystems. In order to ensure the sustainable use of mineral water, it's necessary to calculate the exploitation and utilization of mineral water according to the ecological base flow. In this study, four hydrological methods were used to analyze the intra-annual and inter-annual ecological base flows, namely the Tennant method, the base flow ratio method, the driest monthly average flow method and the Texas method. The results show that the ecological base flow during the flood season is about 3-4 times that during the non-flood season. Affected by rainfall and runoff, the inter-annual ecological base flow also fluctuated within a small range. This study divides the mineral water exploitation coefficient into five categories and proposes an assessment of the mineral water exploitation potential based on the ecological base flow. It shows that the flow of Baijiang River spring group is the largest, but it's exploitation potential is normal. Huangni River spring group at weak level for exploitation because of its small flow rate. It's obvious that river runoff is not the only factor that determines the exploitation coefficient of the spring group. The proportion of ecological base flow and the proportion of river base flow are also important factors.

hCINAP is potentially a direct target gene of HIF-1 and is required for hypoxia-induced EMT and apoptosis in cervical cancer cells.

The early metastasis of cervical cancer is a multistep process requiring the cancer cells to adapt to the signal input from different tissue environments, including hypoxia. Hypoxia-induced epithelial-to-mesenchymal transition (EMT) plays a critical role in the ability to invade surrounding tissues. However, the molecular mechanisms underlying EMT in cervical cancer remain to be elucidated. Herein, we show that hypoxia-inducible factor-1alpha (HIF-1α) and aryl hydrocarbon receptor nuclear translocator (ARNT) are recruited to the human coilin-interacting nuclear ATPase protein (hCINAP) promoter and initiate hCINAP expression in hypoxia. Ablation of hCINAP decreased the migratory capacity and EMT of cervical cancer cells under hypoxic conditions. Furthermore, hCINAP regulated EMT through the Akt-mTOR signaling pathway, and inhibits hypoxia-induced p53-dependent apoptosis. Our data collectively show that hCINAP may have essential roles in the metastasis of cervical cancer and could be a potential target for curing cervical cancer.

Groundwater fluoride chemistry and health risk assessment of multi-aquifers in Jilin Qianan, Northeastern China.

Groundwater from deep confined aquifers is often recommended for use because of it's low fluoride health risk. Thus, this study appraised groundwater fluoride hydrochemistry in a multi-aquifer system in Jilin Qianan to determine the non-carcinogenic health risk liable from exploiting the respective aquifers. 124 samples collected from the tertiary confined aquifer (N), quaternary confined aquifer (Q1), and quaternary phreatic aquifer (Q3) during surveys in 2001 and 2017 was analyzed using hydrochemical, statistical, spatial, and health risk assessment methods. Results show that the dominant water facies in the respective aquifer layers was Na+K-HCO3+CO3 except in Q1, where Ca+Mg - HCO3 + CO3 was marginally dominant. Fluoride concentrations outside the recommended guideline occurred in all the aquifers except N, where concentrations were optimum. The mean fluoride concentration of groundwater in the aquifers was of the order Q3 (2017) > Q3 (2001) > Q1 > N ( mean 2.09, 2.03, 1.41 and 0.75 mg/L with 51.85%, 57.44%, 36.36% and 0% occurring beyond recommended guideline values respectively). Silicate weathering, cation exchange, and fluorite dissolution in an alkaline environment were the significant fluoride contributing processes. Evaporation and MgF+ complex additionally influenced Q1 and Q3 (2017). The total hazard quotient (THQ) from oral and dermal pathways shows fluoride health risks in the order: infant > children > adult. The associated risks likely from using water in the respective aquifer layers is of the order Q3 (2017) > Q3 (2001) > Q1 > N. The mean groundwater fluoride in 2017 was marginally higher than that of 2001 ( 2.09>2.03 mg/L respectively) although the percentage of age group members disposed to fluoride risk from using water from Q3 decreased from 2001 to 2017. Knowledge of local hydrogeology in exploiting deep groundwater free of fluoride pollution and on-site defluoridation treatment of groundwater was recommended in the study area and other areas with similar characteristics.

State, source and triggering mechanism of iron and manganese pollution in groundwater of Changchun, Northeastern China.

The present state of iron (Fe) and manganese (Mn) concentration in groundwater of Changchun city located within the Songnen Plain of northeastern China was evaluated in this study. Heavy metal sources, as well as triggering mechanism, were analyzed using a physicochemical, statistical and spatial approach. Results revealed that out of the 2600 samples analyzed, 214 (representing 8.24%) for Fe and 606 wells (representing 23.34%) for Mn exceeded the water standard. Organic matter-rich sediments and Fe-Mn nodules in aquifer and soil serve as sources of Fe and Mn. Organic and inorganic complex formations, as well as long residence time, were found to foster the release of Fe and Mn into groundwater. Additionally, pH and well depth was important in triggering Mn dissolution while groundwater mineralization, depth to the water table and well proximity to the river were found to have minimal/negligible effect on heavy metal mobilization. The removal of Fe and Mn from the water before use was proposed along with the sinking of deeper wells for groundwater exploitation to limit the use of polluted water.

Regio- and Stereoselective Electrophilic Cyclization Approach for the Protecting-Group-Free Synthesis of Alkaloids Lennoxamine, Chilenine, Fumaridine, 8-Oxypseudoplamatine, and 2- O-(Methyloxy)fagaronine.

A unified strategy for protecting-group-free synthesis of alkaloids lennoxamine, chilenine, fumaridine, 8-oxypseudoplamatine, and 2- O-(methyloxy)fagaronine is reported. The core isoindolin-1-one and isoquinolin-1-one structures were built by a silver-catalyzed regio- and stereoselective cyclization of methyl 2-alkynylbenzimidates. The regioselectivity of cyclization was achieved by utilizing the intrinsic functionality of alkaloids.

Formation and transformation of chloroform during managed aquifer recharge (MAR).

Chlorination is an effective method to protect the safety of groundwater systems during managed aquifer recharge. However, chlorination leads to the formation of disinfection by-products, whose behavior in aquifers remains unclear and has caused public concern. In this study, an in-site test was performed on an anoxic aquifer in Shouguang City, China, to investigate the formation and transformation of chloroform during managed aquifer recharge. The field tests showed that the formation of chloroform in groundwater caused by the recharge of chlorinated water, and that the fate of chloroform was affected by adsorption and biodegradation. The retardation factor was 1.27, and the half-life was 29 days. The formation and transformation of chloroform during continuous recharge under different hydrochemical conditions was further investigated by batch experiments. These experiments showed that the formation of chloroform increased with contact time, tended to be stable after 10 h, and was facilitated by high chloride/TOC ratios, high pH, and low ionic strength (IS) for a given contact time. The adsorption experiments showed that the process accords with the pseudo-second-order kinetic equations and the Freundlich model. The adsorption capacity was pH dependent (1.01-1.66 µg/g at pH 5 and 2.17-3.05 µg/g at pH 9). Increasing the IS promotes adsorption. The results from biodegradation experiments indicated that the biodegradation was well fitted by the Monod equation. The retardation factor in the batch experiments was close to that of the field test, but the half-life was less than the field test. This is mainly due to the difference in the concentration of dissolved oxygen.

Hydrogeochemical tracing of mineral water in Jingyu County, Northeast China.

The east Jilin Province in China, Jingyu County has been explored as a potential for enriching mineral water. In order to assess the water quality and quantity, it is of crucial importance to investigate the origin of the mineral water and its flow paths. In this study, eighteen mineral springs were sampled in May and September of 2012, May and September of 2013, and May 2014 and the environment, evolvement, and reaction mechanism of mineral water formation were analysed by hydrochemical data analysis, geochemical modelling and multivariate statistical analysis. The results showed that the investigated mineral water was rich in calcium, magnesium, potassium, sodium, bicarbonate, chloride, sulphate, fluoride, nitrate, total iron, silicate, and strontium, and mineral water ages ranged from 11.0 to more than 61.0 years. The U-shape contours of the mineral ages indicate a local and discrete recharge. The mineral compositions of the rocks were olivine, potassium feldspar, pyroxene, albite, and anorthite and were under-saturated in the mineral water. The origin of mineral water was from the hydrolysis of basalt minerals under a neutral to slightly alkaline and CO2-rich environment.

Improving prediction of groundwater quality in situations of limited monitoring data based on virtual sample generation and Gaussian process regression.

The increasing pollution of aquifers by human activities over recent decades poses a threat to drinking water safety. While Gaussian Process Regression (GPR) is a robust tool for predicting and monitoring water quality, its effectiveness is hindered limitations of available data on model training and validation, known as the "small sample problem". Various attempts to resolve this problem include virtual sample generation (VSG). This study aimed to increase the accuracy of GPR for predicting water quality in situations of limited datasets. Three VSG methods, namely Multi Distribution Mega-Trend Diffusion (MD-MTD), Generative Adversarial Network (GAN), and t-distributed stochastic nearest neighbor embedding (t-SNE) were compared for enhancing the accuracy of GPR model prediction of Strontium (Sr2+). The models were used to predict Sr2+ in the shallow aquifer system in Songyuan, Jilin Province. The results showed that t-SNE provided the most significant improvement to the accuracy of the GPR, with R2 increasing from 0.86 to 0.99 (12.98 %), followed by MD-MTD (R2 of 0.95, 9.39 %), with the least improvement obtained by GAN (R2 of 0.92, 5.98 %). Boxplots show that MD-MTD-GPR predictions do not fully capture observed data distributions. GANs accurately replicate the data distribution, while t-SNE-GPR achieves the highest prediction accuracy and handles data fluctuations. GPR accuracy improves with an increasing number of virtual samples but tends to decrease when the number exceeds 258 in this study. This study can guide the improvement of the accuracy of GPR for situations of limited datasets. The results of this study can help improve water quality management and drinking water safety in regions with sparse monitoring data.

The role of PD-L1 in patients with non-small cell lung cancer receiving neoadjuvant immune checkpoint inhibitor plus chemotherapy: a meta-analysis.

BACKGROUND: The use of immune checkpoint inhibitors (ICIs) as neoadjuvant therapy is a promising novel approach in resectable non-small-cell lung cancer (NSCLC). This study aimed to investigate the prognostic value of PD-L1 in patients with NSCLC receiving neoadjuvant immune checkpoint inhibitor plus chemotherapy (CT). MATERIALS AND METHODS: Several databases (PubMed, Embase, and cochrane central register of controlled trials [CENTRAL]) were systematically searched. Randomized controlled trials (RCTs) investigating pathological and survival outcomes with neoadjuvant ICI + CT versus CT alone in NSCLC were analyzed. RESULTS: Overall, eight RCTs (n = 3,404) were included. The analyses showed neoadjuvant ICI + CT significantly improved complete pathological response (pCR) and event-free survival (EFS) in either tumor PD-L1 < 1%, ≥ 1%, 1-49%, or ≥ 50% population (both p < 0.0001) compared with neoadjuvant CT alone. The overall survival (OS) data are not yet mature among all included RCTs, and only three RCTs presented OS data by PD-L1 status of patients. The pooled OS favored neoadjuvant ICI + CT in the PD-L1 ≥ 1% population (hazard ratio [HR], 0.45; 95% CI, 0.31-0.65; p < 0.0001), but not in the PD-L1 < 1% population (HR, 0.89; 95% CI, 0.66-1.19; p = 0.43). CONCLUSIONS: Compared with neoadjuvant CT alone, neoadjuvant ICI + CT significantly enhanced pCR and EFS for patients with resectable NSCLC regardless of the expression of PD-L1. It seems that only patients with PD-L1 positive tumors may achieve a better OS, but it's currently inconclusive due to immature data, so future research with long-term follow-up is still needed.

Hydrochemical characteristics and the impact of human activities on groundwater in a semi-arid plain: a case study of western Jilin Province, Northeast China.

Groundwater is important for human survival and development, particularly in arid and semi-arid regions. This study aimed to analyze the hydrochemical characteristics, influencing factors, and the impact of human activities on groundwater in the semi-arid plains of western Jilin Province, northwest China. The study collected 88 and 151 phreatic and confined water samples, respectively, which were analyzed for 13 water quality indicators using statistical and graphical methods. In order to investigate the impact of anthropogenic activities on water quality and health risks, the improved combined weighted water quality index (ICWQI) based on the entropy weight, criteria importance though inter-criteria correlation (CRITIC), the coefficient of difference method, subjective weight based on quality grading criteria, and the water quality index (WQI) were proposed to evaluate the water quality of the study area. Meanwhile, the human health risk assessment (HHRA) model was used to assess the risks of nitrate to the health of humans in different ages and sex categories. The results indicated that the groundwater in the study area was weakly alkaline and the main hydrochemical types in the phreatic and confined water were HCO3-·Ca-Mg and HCO3--Na. Rock weathering was the dominant process responsible for the generation of groundwater ions, the ions in groundwater primarily originate from the dissolution of halite, gypsum, and feldspar, while dolomitization promotes an increase in Mg2+. Human activities lead to an increase in NO3- in groundwater and have an impact on water quality and human health risks. The ICWQI method was found to yield more precise and rational assessments of water quality. Groundwater quality is primarily affected by nitrate ions. The areas in which groundwater nitrate posed a higher risk to human health were found to be mainly in the saline-alkali lands of Qian'an, Tongyu, and Zhenlai. Fertilizers, pesticides, and livestock farming activities contribute to the pollution of surface water. This surface contamination then infiltrates abandoned confined wells, leading to contamination of the confined aquifers. This study can improve the understanding of groundwater hydrochemical characteristics and the impact of human activities on groundwater in the study area. This study can also contribute to the study of groundwater in semi-arid regions.

Severe and fatal adverse events of immune checkpoint inhibitor combination therapy in patients with metastatic renal cell carcinoma: a systematic review and meta-analysis.

Introduction: Immune checkpoint inhibitor (ICI) combination therapy has changed the treatment landscape for metastatic renal cell carcinoma (mRCC). However, little evidence exists on the treatment-related severe adverse events (SAEs) and fatal adverse events (FAEs) of ICI combination therapy in mRCC. Method: We searched PubMed, Embase, and Cochrane Library databases to evaluate randomized controlled trials (RCTs) of ICI combination therapy versus conventional tyrosine kinase inhibitor (TKI)-targeted therapy in mRCC. Data on SAEs and FAEs were analyzed using revman5.4 software. Results: Eight RCTs (n=5380) were identified. The analysis showed no differences in SAEs (60.5% vs. 64.5%) and FAEs (1.2% vs. 0.8%) between the ICI and TKI groups (odds ratio [OR], 0.83; 95%CI 0.58-1.19, p=0.300 and OR, 1.54; 95%CI 0.89-2.69, p=0.120, respectively). ICI-combination therapy was associated with less risk of hematotoxicities, including anemia (OR, 0.24, 95%CI 0.15-0.38, p<0.001), neutropenia (OR, 0.07, 95%CI 0.03-0.14, p<0.001), and thrombocytopenia (OR, 0.05, 95%CI 0.02-0.12, p<0.001), but with increased risks of hepatotoxicities (ALT increase [OR, 3.39, 95%CI 2.39-4.81, p<0.001] and AST increase [OR, 2.71, 95%CI 1.81-4.07, p<0.001]), gastrointestinal toxicities (amylase level increase [OR, 2.32, 95%CI 1.33-4.05, p=0.003] and decreased appetite [OR, 1.77, 95%CI 1.08-2.92, p=0.020]), endocrine toxicity (adrenal insufficiency [OR, 11.27, 95%CI 1.55-81.87, p=0.020]) and nephrotoxicity of proteinuria (OR, 2.21, 95%CI 1.06-4.61, p=0.030). Conclusions: Compared with TKI, ICI combination therapy has less hematotoxicity in mRCC but more specific hepatotoxicity, gastrointestinal toxicity, endocrine toxicity, and nephrotoxicity, with a similar severe toxicity profile. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023412669.

Groundwater Quality Assessment in the Northern Part of Changchun City, Northeast China, Using PIG and Two Improved PIG Methods.

As a numerical indicator, the pollution index of groundwater (PIG) has gained a great deal of popularity in quantifying groundwater quality for drinking purposes. However, its weight-determination procedure is rather subjective due to the absolute dependence on experts' experience. To make the evaluation results more accurate and convincing, two improved PIG models (CRITIC-PIG and Entropy-PIG) that integrate subjective weights and objective weights were designed, and they were employed to appraise groundwater suitability for drinking purposes in the northern part of Changchun City. A total of 48 water samples (34 unconfined water samples and 14 confined water samples) with abundances of Ca2+ and HCO3- were collected and tested to obtain the data for the analyses. The results showed that 60.4%, 47.9% and 60.4% of the water samples manifested insignificant pollution and were marginally potable based on the values of the PIG, CRITIC-PIG and Entropy-PIG, respectively. Though 48% of the water samples had different evaluation results, their level difference was mostly 1, which is relatively acceptable. The distribution maps of the three sets of PIG values demonstrated that the quality of groundwater was the best in Dehui City and the worst in Nongan County. Groundwater contamination in the study area was mainly caused by the high concentrations of TDS, TH, Fe3+, F- and NO3-, which not only came from geogenic sources but also anthropogenic sources.

A preliminary study on the eco-environmental geological issue of in-situ oil shale mining by a physical model.

As traditional methods of oil shale production emitting high levels of pollutants, in-situ exploitation has aroused great concerns. In order to study the effect of in-situ pyrolysis products on the underground environment, an in-situ oil shale exploitation of underground environment impact laboratory simulation system was designed. Based on the hydrogeological condition of oil shale area in Nong'an City, a physical simulation test was conducted. It was found the temperature of surrounding layers continued to be perturbed after heating of the formation had stopped. The time during which the temperature was perturbed was about 4-5 times the heating period. During the simulation test, stray gas migration through fractures and faults was considered a mechanism for groundwater contamination. In the test, the maximum TOC content in aquifer was the value of 97.0 mg/L. The maximum total petroleum hydrocarbon (TPH) content of the simulated formation was 129 mg/kg after oil pyrolysis.

Release characteristics of Pb and BETX from in situ oil shale transformation on groundwater environment.

Oil shale has received attention as an alternative energy source to petroleum because of its abundant reserves. Exploitation of oil shale can be divided into two types: ex situ and in situ exploitation. In situ transformation has been favoured because of its various advantages. Heating of oil shale leads to the production of oil and gas. To explore the influence of solid residue after pyrolysis of oil shale on the groundwater environment, we performed ultrapure water-rock interaction experiments. The results showed that Pb tended to accumulate in solid residues during pyrolysis. Additionally, the Pb concentration goes up in the immersion solution over time and as the pyrolysis temperature increased. In contrast, when we measured the soaking data of benzene series, the concentrations of benzene and toluene produced at temperatures over 350 â„ƒ were highest in the four oil shale pyrolysis samples after pyrolysis. The water-rock interaction experiment for 30 days led to benzene and toluene concentrations that were 104 and 1070-fold over the limit of China's standards for groundwater quality. Over time, the content of benzene series was attenuated via biological actions. The results show that in situ oil shale mining can lead to continuous pollution in the groundwater environment.

Effects of the natural environment and human activities on iron and manganese content in groundwater: a case study of Changchun city, Northeast China.

Excessive Fe and Mn in groundwater of the Songnen Plain, northeast China, pose a threat to water security. Human activities over recent decades have had significant effects on the water quantity and quality of the Songnen Plain. By adopting the large city of Changchun in the Songnen Plain as a research area, this study analyzed the effects of the natural environment (including characteristics of soil and aquifer, climate, and groundwater level) and human activities (including groundwater salinization, groundwater exploitation, and nitrate effects) on groundwater Fe and Mn using statistical and spatial analysis methods. The results showed that the characteristics of soil and aquifer determine the source of groundwater Fe and Mn. The correlations between Fe and Mn with TDS (total dissolved solids) increased with increasing TDS from southeast to northwest in different microclimate regions. The salinization of groundwater caused by human activities will also lead to the increase of Fe content. The decrease in groundwater Fe and Mn was attributed to an increase in groundwater [Formula: see text], through the use of chemical fertilizers. The variation of Fe concentration in groundwater corresponded well with that of groundwater depth, but the excessive exploitation will lead to the continuous decrease in groundwater level and a corresponding decrease in the concentration of groundwater Fe. This study provides a reference for understanding the influence of human activities and the natural environment on groundwater hydrochemistry in the Songnen Plain.