The materials and byproducts of the processes used in the metal finishing industry are released as particle contaminants into the air in the workplace. The present study aimed to determine the concentrations and size distributions of these particles and of elements chromium, nickel, copper, manganese, cobalt, and lead (Cr, Ni, Cu, Mn, Co, and Pb, respectively) in a metal finishing industry and evaluate their potential health risks. Particles that are airborne from the dipping baths in the plant were sampled using a Sioutas cascade impactor at five different size fractions (PM>₂.₅, PM₁.₀–₂.₅, PM₀.₅–₁.₀, PM₀.₂₅–₀.₅, PM<₀.₂₅) and gravimetric analyses were conducted on the sampled filters. The GF-AAS 600 graphite atomic absorption spectrophotometer (PerkinElmer Corporation, Waltham, MA, USA) was used to analyze the elements and the method of USEPA was used to assess the health risk. The ratio of fine particles (PM₂.₅) to total suspended particles (TSPs) was 0.6. We observed that 50% of TSPs were composed of PM₁.₀ and that 68–88% of the metals were found in the fine particle fractions. Pb, Cr, and Mn were significantly positively correlated in the PM₁.₀ fraction, and the highest linear relationship was found between Pb and Cr (r = 0.85, p < 0.01). The total hazard quotient (HQ) for PM₂.₅ was 1.43, which is higher than the acceptable limit of 1.0. The excess lifetime cancer risk (ELCR) for hexavalent chromium (Cr[VI]) in PM₂.₅ was 6.09 × 10⁻⁵ for female workers and 6.54 × 10⁻⁵ for male workers, which are higher than the acceptable limit of 1.0 × 10⁻⁶, while total ELCRs for female and male workers were 6.21 × 10⁻⁵ and 6.21 × 10⁻⁵, respectively. The lifetime cancer risk associated with Cr(VI) in Cr electroplating plants should be taken into consideration as a significant health risk for the workers.

Until now, a number of epidemiological studies have focused on the association between ambient particulate matter pollution and chronic obstructive pulmonary disease (COPD), especially in developed countries. There are limited evidences on the association between short-term exposure to particulate matters (PM₂.₅, PMC, and PM₁₀) and overall hospital outpatient visits for COPD at the same time in China. Thus, a time-series analysis on the short-term association between three subtypes of PM (PM₂.₅, PMC, and PM₁₀) and daily hospital outpatients for COPD in Lanzhou, China was conducted, from 2014 to 2017.An over dispersed, generalized additive model was used to analyze the associations after controlling for time trend, weather conditions, day of the week, and holidays. Stratified analyses were also performed by age and gender. The results disclosed that a 10-μg/m³ increase in PM₂.₅ concentration at a lag of 0–7 days was associated with 1.190% (95% CI 0.176~2.215%). For PMc, therewere not statistically significant effects at any lag days, but we could find the greatest effect at lag07 that a 10-μg/m³ increase in concentration was associated with 0.014% (95% CI − 0.065~0.093%). PM₁₀ also exerted a high effect for COPD (0.185% increase; 95% CI − 0.046~0.417%) when 6 days of exposures (lag6), however, no significance relationship could be found. For COPD among males, positive results were observed for PM₂.₅ with lags of 0–7 days, a 10-μg/m³ increase was 1.184% (95% CI 0.095~2.284%). The effect of PM₂.₅ on females was also most significant at lag07, a 10-μg/m³ increase was 1.254% (95% CI 0.053~2.469%). For those aged < 65 years old, PM₂.₅ was not statistically significant at all lag days, but it reached the maximum at lag07, a 10-μg/m³ increase was 0.978% (95% CI − 0.139~2.108%). For those aged 65 ≥ years old and older, PM₂.₅ had a statistically significant lag effect at lag1, lag2, lag3, lag02, lag03, lag04, lag05, lag06, and lag07, and it was most significant at lag07; a 10-μg/m³ increase was 1.906% (95% CI 0.553~3.277%). Short-term exposure to PM₂.₅ was associated with increased risk of hospital visits for COPD. In particular, the elderly (aged ≥ 65 years old) and males were relatively more sensitive to PM₂.₅, and were affected right away after the PM₂.₅ concentration went up.

The aim of this study was to explore the enterprises in the mining area, in the face of environmental pollution, to use relationship embedding to acquire new key knowledge from the external network, and to improve environmental governance performance. In this paper, a model between relationship embedding and environmental governance performance was established, and five main hypotheses were proposed. Luliang Mountain Area is a typical mining area in China. And this study used 310 sample datum and regression analysis to empirically test the mechanism, taking Luliang Mountain Area as an example. First, SPSS statistical software was used for reliability and validity analysis of the questionnaire, and the results showed good. Then regression analysis was performed to test the hypothesis. The results showed that relationship embedding has a significant positive impact on environmental governance performance, and enterprises in the mining area use relationship embedding to obtain key knowledge, which can enhance environmental governance performance. Internal social capital has a positive adjustment effect on the relationship between relationship embedding and knowledge acquisition. In order to control environmental pollution in the mining area, enterprises should make full use of the relationship embedding, acquire new key knowledge, improve environmental governance capacity, and improve the environmental governance performance of enterprises.

In the present study, cost-effective, and environmentally friendly fabrication of silver and gold nanoparticles was performed by using aqueous extract of waste corn-cob. The formation of the metallic nanoparticles (MNPs) was optimized by UV–Vis method. The phytoconstituents were responsible for reduction of silver and gold ions to silver nanoparticles (CC-AgNPs) and gold nanoparticles (CC-AuNPs) which were demonstrated by Fourier-transform infrared (FTIR) spectroscopy while formation of AgCl was attributed to the presence of chloride ions in the aqueous extract. The crystalline nature of the AgNPs, AgCl, and AuNPs was confirmed using the X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns. Morphological studies showed that the synthesized CC-AgNPs existed in spherical shape with the size ranging from 2 to 28 nm possessing an average value of 11 nm while CC-AuNPs were present in the multiple shapes with size ranging from 5 to 50 nm possessing an average value of 35 nm. For studies on bioactive application, the CC-AgNPs exhibited a high antibacterial activity against three bacterial strains including Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. In addition, the catalytic efficiency of MNPs was investigated for reduction of o-, m-, p-nitrophenols, and degradation of organic dyes including Eosin Y and Rhodamine 6G. The rate constants calculated from the kinetical data revealed that the biosynthesized nanoparticles are excellent catalysts in potential applications for treatment of wastewater. Graphical abstract .

In this study, we aim to determine the median lethal dose (LD₅₀) of glyphosate isopropylamine salt (GI), which is commonly used in the world and especially in Turkey against to weeds, in male and female rats by using the probit or logit analysis method. A total of 140 Wistar rats were used, including 70 females and 70 males. To determine LD₅₀, the male and female rats were randomized into 7 groups made up of 10 animals in each group. At doses of 6000, 6500, 7000, 7500, 8000, 8500, and 9000 mg / kg, GI was administered to the male and female rats by oral gavage. After dosing, the animals were periodically monitored for 14 days. No deaths were observed after 48 h of herbicide application. In this study, only logit analysis was used for the LD₅₀ value to be calculated in the male rats within 24 h, while other analyses were carried out with the probit method. In the female and male rats, the LD₅₀ levels of GI between 24 and 48 h were determined as 7444.26–7878.50 mg/kg and 7203.58–7397.25 mg/kg, respectively. According to these results, it was concluded that female rats are more sensitive to GI than male rats. We believe that the findings that were obtained will guide researchers, clinicians, and toxicologists through preventive and curative studies against acute poisoning that may occur with GI.

The purpose of this study was to investigate, for the first time, the effects of Bifenthrin (Bif) chronic exposure on plasmatic and aortic lipid parameters disturbance and their pro-atherogenic possibility in Wistar rats. The ameliorative role of vitamin E (Vit E) and selenium (Se) were also targeted. Thus, rats were treated by gastric gavage with combination of Vit E (100 mg/kg/bw) and Se (0.25 mg/kg/bw) in alone and co-treated groups for 90 days. Apart from control and Vit E-Se groups, all the groups were subjected to Bif (3 mg/kg, via gavage) toxicity. Results showed that Bif increased markedly plasmatic and aortic total cholesterol, LDL-cholesterol, native LDL-apoB-100, and oxidized-LDL, compared to the control. Moreover, Bif treatment significantly increased the plasmatic levels of the pro-inflammatory cytokines TNF-α, IL-2, and IL-6. In addition, the densitometric quantification of protein bands showed that the amount of hepatic native LDL-receptor protein decreased significantly in the intoxicated rats compared to the control group. The expression of arterial LDL receptors (LDLRs) and scavenger receptors (CD36) was amplified owing to Bif toxicity. This harmful effect was confirmed by histological study using Oil-Red-O staining. Owing to their antioxidant capacities, Vit E and Se have maintained all the changes in plasma and aorta lipids and prevented the pro-atherogenic effect observed in Bif-treated animals.

The objective of this study was to develop a process for the synthesis of magnetite nanocomposites from raffinate of hydrometallurgical plants containing iron ions. Towards this goal, a three-step process was developed. After the reduction of Fe(III) to Fe(II) in the first stage, Al³⁺ in the raffinate was precipitated as Al(OH)₃ and finally magnetite NPs were synthesized by chemical co-precipitation method via controlling the oxidation-reduction potentials (ORPs). The produced nanomaterials were analyzed using XRD, TEM, VSM, TGA, and FTIR. The TG, XPS, and FTIR results affirmed the existence of PVA while TEM images illustrated the spherical nanoparticles with an average size of about 19 ± 4 nm. Evaluation of VSM data indicated the highly ferromagnetic behavior for Fe₃O₄ and Fe₃O₄@PVA products at the room temperature with a saturation magnetization of 46.98 and 35.78 emu/g, respectively.

Children’s health, attendance, and academic performance may be affected by school environmental hazards. While prior studies evaluated home environment and health, few have evaluated indicators of school in-/outdoor environment and health. This study addresses this knowledge gap by systematically reviewing and evaluating outdoor and indoor indicators of school environment and student’s health and performance in New York State (NYS). We also evaluate statistical methodologies to address highly correlated indicators and integrate multiple exposures. Multiple school environmental indicators were identified from various existing NYS datasets. We summarized data sources, completeness, geographic and temporal coverage, and data quality for each indicator. Each indicator was evaluated by scientific basis/relevance, analytic soundness/feasibility, and interpretation/utility, and validated using objective NYS data. Finally, advanced variable selection methods were described and discussed. We have identified and evaluated multiple school environmental health indicators. It was found that mold and moisture problems, ventilation problems, ambient ozone, and PM₂.₅ levels are among the top priorities of school environmental issues/indicators in NYS, which were also consistent while using NYS data. Choice of best variable selection method should be made based on the research questions and data characteristics. The school environmental health indicators identified, and variable selection methods evaluated, in this study could be used by other researchers to help school officials and policy makers initiate prevention programs.

Natural resource-rich countries transfer more sources to military expenditures due to extreme security concerns. As public revenues have declined due to the decline in oil prices, military expenditures have been cut in many countries. Nevertheless, this is not valid for all countries. Even in some countries, despite the decrease in oil prices and volatility, military expenditures increase. The aim of this study is to investigate the relationship between volatility in oil prices and military expenditures in GCC countries (United Arab Emirates, Bahrain, Qatar, Kuwait, Saudi Arabia, and Oman). The analysis period was determined differently for each country depending on the availability of data. UAE and Qatar were excluded from the analysis as the defense expenditures data of these countries could not be provided regularly. ARDL model was preferred for the research. According to the bound test results, there is a cointegration relationship between the variables in all countries. Besides, the long-term results showed that the volatility in oil prices in all countries, except for Bahrain, positively affects military expenditures. The error correction model indicated that there is a reverse relationship between oil price volatility and military expenditures. These findings indicated that despite the volatility in oil prices, military expenditures in GCC countries are not reduced.

Nitrites are found in several forms; they are widely found in water resources and used as additives and preservatives for food and as a color source. We investigated the hazardous effects of exposing rats to different doses of nitrites. Moreover, we examined such impacts, after acute ingestion, on liver and renal tissues in rats and to what extent this affects the organs’ functions. Animals were divided into five groups: one control group 1 (group C) and four sodium nitrite (NaNO₂)–treated group (8 rats per group). The four NaNO₂-treated groups include group 2 (N20), group 3 (N40), group 4 (N60), and group 5 (N75). NaNO₂ was dissolved in distilled water, and single acute dose was orally given by gavage at 20, 40, 60, and 75 mg/kg body weight, respectively. Our results revealed significant increase of liver enzymes activity—aspartate transaminase (AST), alanine aminotransferase (ALT), and creatinine between different groups with increasing doses of nitrite ingestion. The results of hepatic and renal oxidative stress showed significant increase in the malondialdehyde (MDA) levels and significant decrease in the antioxidant parameters, such as reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), as the dose of nitrite increases. Further, the methemoglobin percent showed significant increase with increasing nitrite doses. Abnormal morphological alterations in the liver and kidney tissues were obviously proportional to the administered nitrite doses. The expression of caspase 3 and Bax level showed enhanced induction of immunoexpression, especially in the high doses of nitrites. On the other hand, the maximal immunoexpression level of anti-apoptotic marker Bcl₂ was found in lower doses of nitrites, whereas marked decrease of Bcl₂ levels was observed in the higher doses. In conclusion, administration of sodium nitrite in a dose-dependent manner is capable of inducing cellular and genetic toxicities and causes disturbance in biochemical analysis, oxidative and anti-oxidative balance, and methemoglobinemia. It also makes histopathological alterations and leads to the activation of apoptosis-related Bax, Bcl₂, and caspase 3 genes of liver and kidney tissues in rats.