BACKGROUND: Chronic kidney disease (CKD) carries a high public health burden yet little is known about the relationship between metalworking fluid (MWF) aerosols, occupational noise and CKD. We aimed to explore the relationship between occupational MWF aerosols, occupational noise and CKD.
METHODS: A total of 2,738 machinists were sampled from three machining companies in Wuxi, China, in 2022. We used the National Institute for Occupational Safety and Health (NIOSH) method 5524 to collect individual samples for MWF aerosols exposure, and the Chinese national standard (GBZ/T 189.8-2007) method to test individual occupational noise exposure. The diagnostic criteria for CKD were urinary albumin/creatinine ratio (UACR) of ≥ 30 mg/g and reduced renal function (eGFR < 60 mL.min- 1. 1.73 m- 2) lasting longer than 3 months. Smooth curve fitting was conducted to analyze the associations of MWF aerosols and occupational noise with CKD. A segmented regression model was used to analyze the threshold effects.
RESULTS: Workers exposed to MWF aerosols (odds ratio [OR] = 2.03, 95% confidence interval [CI]: 1.21-3.41) and occupational noise (OR = 1.77, 95%CI: 1.06-2.96) had higher prevalence of CKD than nonexposed workers. A nonlinear and positive association was found between increasing MWF aerosols and occupational noise dose and the risk of CKD. When daily cumulative exposure dose of MWF aerosols exceeded 8.03 mg/m3, the OR was 1.24 (95%CI: 1.03-1.58), and when occupational noise exceeded 87.22 dB(A), the OR was 1.16 (95%CI: 1.04-1.20). In the interactive analysis between MWF aerosols and occupational noise, the workers exposed to both MWF aerosols (cumulative exposure ≥ 8.03 mg/m3-day) and occupational noise (LEX,8 h ≥ 87.22 dB(A)) had an increased prevalence of CKD (OR = 2.71, 95%CI: 1.48-4.96). MWF aerosols and occupational noise had a positive interaction in prevalence of CKD.
CONCLUSIONS: Occupational MWF aerosols and noise were positively and nonlinearly associated with CKD, and cumulative MWF aerosols and noise exposure showed a positive interaction with CKD. These findings emphasize the importance of assessing kidney function of workers exposed to MWF aerosols and occupational noise. Prospective and longitudinal cohort studies are necessary to elucidate the causality of these associations.

The majority of the studies on nanoscale zero-valent iron (nZVI) are conducted at a laboratory-scale, while field-scale evidence is scarce. The objective of this study was to compare the metal(loid) immobilization efficiency of selected Fe-based materials under field conditions for a period of one year. Two contrasting metal(loid) (As, Cd, Pb, Zn) enriched soils from a smelter-contaminated area were amended with sulfidized nZVI (S-nZVI) solely or combined with thermally stabilized sewage sludge and compared to amendment with microscale iron grit. In the soil with higher pH (7.5) and organic matter content (TOC = 12.7 %), the application of amendments resulted in a moderate increase in pH and reduced As, Cd, Pb, and Zn leaching after 1-year, with S-nZVI and sludge combined being the most efficient, followed by iron grit and S-nZVI alone. However, the amendments had adverse impacts on microbial biomass quantity, S-nZVI being the least damaging. In the soil with a lower pH (6.0) and organic matter content (TOC = 2.3 %), the results were mixed; 0.01 M CaCl2 extraction data showed only S-nZVI with sludge as remaining effective in reducing extractable concentrations of metals; on the other hand, Cd and Zn concentrations were increased in the extracted soil pore water solutions, in contrast to the two conventional amendments. Despite that, S-nZVI with sludge enhanced the quantity of microbial biomass in this soil. Additional earthworm avoidance data indicated that they generally avoided soil treated with all Fe-based materials, but the presence of sludge impacted their preferences somewhat. In summary, no significant differences between S-nZVI and iron grit were observed for metal(loid) immobilization, though sludge significantly improved the performance of S-nZVI in terms of soil health indicators. Therefore, this study indicates that S-nZVI amendment of soils alone should be avoided, though further field evidence from a broader range of soils is now required.

Reducing CO2 emissions of the iron and steel industry, a typical heavy CO2-emitting sector, is the only way that must be passed to achieve the \'dual-carbon\' goal, especially in China. In previous studies, however, it is still unknown what is the difference between blast furnace-basic oxygen furnace (BF-BOF), scrap-electric furnace (scrap-EF) and hydrogen metallurgy process. The quantitative research on the key factors affecting CO2 emissions is insufficient. There is also a lack of research on the prediction of CO2 emissions by adjusting industrial structure. Based on material flow analysis, this study establishes carbon flow diagrams of three processes, and then analyze the key factors affecting CO2 emissions. CO2 emissions of the iron and steel industry in the future is predicted by adjusting industrial structure. The results show that: (1) The CO2 emissions of BF-BOF, scrap-EF and hydrogen metallurgy process in a site are 1417.26, 542.93 and 1166.52 kg, respectively. (2) By increasing pellet ratio in blast furnace, scrap ratio in electric furnace, etc., can effectively reduce CO2 emissions. (3) Reducing the crude steel output is the most effective CO2 reduction measure. There is still 5.15 × 108-6.17 × 108 tons of CO2 that needs to be reduced by additional measures.

To conduct a precise health risk assessment of heavy metals (HMs) in soil, it is imperative to ascertain the primary sources of potential health risks. In this study, we conducted comprehensive measurements of HMs, specifically focusing on the accumulation of Cu, Cd, Sb, Zn, and Pb in local soil, which may pose threats to environmental quality. To achieve our objective, we employed a method that combines positive matrix factorization with a health risk assessment model to quantify the health risks associated with specific sources. The results obtained from the geo-accumulation index indicate that the majority of HMs found in the local soil are influenced by anthropogenic activities. Among these sources, local industrial-related activities contributed the largest proportion of HMs to the soil at 34.7%, followed by natural sources at 28.7%, mining and metallurgy-related activities at 28.2%, and traffic-related activities at 8.40%. Although the non-carcinogenic and carcinogenic risks associated with individual HMs were found to be below safety thresholds, the cumulative health risks stemming from total HMs exceeded safety limits for children. Moreover, the unacceptable health risks for children originating from industrial-related activities, natural sources, and mining and metallurgy-related activities were primarily concentrated in proximity to mining sites and industrial areas within the local region. This investigation furnishes valuable insights that can aid governmental authorities in formulating precise control policies to mitigate health threats posed by soils in polymetallic mining areas.

This study was designed to study dual risk of MWFs and vibration according to exposure simulation of selected industry. Air samples of two types MWFs were evaluated according to NIOSH 5026. Vibration acceleration exposure was assessed based on the ISO 8041:2005 standard. Cell treatment of both MWF air samples and vibration as the same as dual exposure to MWF airborne and vibration was assessed. There is a potency of nitrosamine formation in airborne samples of ethylamine containing MWF, while heterocyclic including bore is found in airborne bore containing MWF. DNA breaks caused by boron-containing MWF were higher than nitrosamine air samples. Oxidative stress production and chronic inflammation were highlighted in the response to cell treatments. The risk of cell toxicity in machining workers was evaluated at a level lower than the occupational exposure limit for MWFs and vibration.

Electrolytic manganese residue (EMR) and red mud (RM) are solid waste by-products of the metal manganese and alumina industries, respectively. Under long-term open storage, ammonia nitrogen and soluble manganese ions in EMR and alkaline substances in RM severely pollute and harm the environment. In order to alleviate the pollution problem of EMR and RM. In this study, the alkaline substances in RM were used to treat ammonia nitrogen and soluble manganese ions in EMR. The results confirm the following suitable treatment conditions for the mutual treatment of EMR and RM: EMR-RM mass ratio = 1:1, liquid-solid ratio = 1.4:1, and stirring time = 320 min. Under these conditions, the elimination ratios of ammonia nitrogen (emitted in the form of ammonia gas) and soluble manganese ions (solidified in the form of Mn3.88O7(OH) and KMn8O16) are 85.87 and 86.63%, respectively. Moreover, the alkaline substances in RM are converted into neutral salts (Na2SO4 and Mg3O(CO3)2), achieving de-alkalinisation. The treatment method can also solidify the heavy metal ions-Cr3+, Cu2+, Ni2+, and Zn2+-present in the waste residue with leaching concentrations of 1.45 mg/L, 0.099 mg/L, 0.294 mg/L, and 0.449 mg/L, respectively. This satisfies the requirements of the Chinese standard GB5085.3-2007. In the mutual treatment of EMR and RM, the kinetics of ammonia nitrogen removal and manganese-ion solidification reactions are controlled via a combination of membrane diffusion and chemical reaction mechanisms.

The incidence of DNA damage from exposure to specific types of metalworking fluids has been reported. In this research, size-selective permissible limits to prevent genotoxic damage in A549 cell lines exposed to two types of mineral oil were estimated for the first time using a benchmark dose approach and extrapolated to workers. The comet assay was performed based on Olive and Banath protocol to determine DNA damage. Then, the Benchmark Dose, the 95% lower bound confidence limit BMD, and the 95% upper-bound confidence limit BMD were determined using continuous response data. Finally, the four Benchmark Dose levels reported in the A549 cell line were extrapolated to the human population in occupational settings in two phases. This study showed when determining the permissible limits, the type used or unused, the type of injury, the organ affected in the body and the size of the particles should also be considered.

The decommissioning of uranium mining and metallurgy facilities involves sensitive issues of the local government and the public, which is related to the vital interests of the surrounding residents. Improper disposal may lead to negative emotions among the public and affect the process of uranium mining and metallurgy facilities decommissioning projects. In order to explore the acceptance of uranium mining and metallurgy decommissioning projects by nearby residents and its influencing factors, a hypothesis model of influencing factors of public acceptance was constructed through literature survey. Taking the public around a uranium mining and metallurgy in Hunan Province as an example, a questionnaire survey was carried out. Using the AMOS21.0 tool, the fitting test of the structural equation model was carried out on 506 valid sample data and the hypothetical model, and the key factors affecting the public acceptance of the uranium mining and metallurgy decommissioning project were analyzed. The findings show that public perceived risk (-0.28), familiarity (0.26) and trust (0.175) are key factors influencing acceptance. The research results provide a methodological basis for improving the public acceptance of uranium mining and metallurgy decommissioning projects.

In this paper, the problem of the identification of undesirable events is discussed. Such events can be poorly represented in the historical data, and it is predominantly impossible to learn from past examples. The discussed issue is considered in the work in the context of two use cases in which vibration and temperature measurements collected by wireless sensors are analysed. These use cases include crushers at a coal-fired power plant and gantries in a steelworks converter. The awareness, resulting from the cooperation with industry, of the need for a system that works in cold start conditions and does not flood the machine operator with alarms was the motivation for proposing a new predictive maintenance method. The proposed solution is based on the methods of outlier identification. These methods are applied to the collected data that was transformed into a multidimensional feature vector. The novelty of the proposed solution stems from the creation of a methodology for the reduction of false positive alarms, which was applied to a system identifying undesirable events. This methodology is based on the adaptation of the system to the analysed data, the interaction with the dispatcher, and the use of the XAI (eXplainable Artificial Intelligence) method. The experiments performed on several data sets showed that the proposed method reduced false alarms by 90.25% on average in relation to the performance of the stand-alone outlier detection method. The obtained results allowed for the implementation of the developed method to a system operating in a real industrial facility. The conducted research may be valuable for systems with a cold start problem where frequent alarms can lead to discouragement and disregard for the system by the user.

The aim of this review is to provide a critical overview of the physical properties (surface hardness, cutting efficiency, bending properties, flexibility, cyclic fatigue resistance) of NiTi instruments. Frequently used experimental models regarding these aspects will be presented and discussed with regard to their strengths and weaknesses. For all these aspects a plethora of experimental models have been described. Based on a critical appraisal and especially taking the appropriate translation of experimental findings to clinical endodontics into account, suggestions for future research based on clearly defined and valid experimental methodologies will be provided. Up to now, very few attempts have been made to assess, which particular physical properties of NiTi instruments exert an impact on the clinical outcome of root canal treatment. Departure from merely focusing on physical properties and fracture characteristics towards more biological aspects in terms of treatment outcome is essential.