Nephrotoxicity effects of the wood preservative chromium copper arsenate on mice: histopathological and quantitative approaches

Identification and quantification of Cr, Cu, and As incidental nanomaterials derived from CCA-treated wood in wildland-urban interface fire ashes

In addition to the combustion of vegetation, fires at the wildland-urban interface (WUI) burn structural materials, including chromated copper arsenate (CCA)-treated wood. This study identifies, quantifies, and characterizes Cr-, Cu-, and As-bearing incidental nanomaterials (INMs) in WUI fire ashes collected from three residential structures suspected to have originated from the combustion of CCA-treated wood. The total elemental concentrations were determined by inductively coupled plasma-time of flight-mass spectrometry (ICP-TOF-MS) following acid digestion. The crystalline phases were determined using transmission electron microscopy (TEM), specifically using electron diffraction and high-resolution imaging. The multi-element single particle composition and size distribution were determined by single particle (SP)-ICP-TOF-MS coupled with agglomerative hierarchical clustering analysis. Chromium, Cu, and As are the dominant elements in the ashes and together account for 93%, 83%, and 24% of the total mass of measured elements in the ash samples. Chromium, Cu, and As phases, analyzed by TEM, most closely match CrO₃, CrO₂, eskolaite (Cr₂O₃), CuCrO₂, CuCr₂O₄, CrAs₂O₆, As₂O₅, AsO₂, claudetite (As₂O₃, monoclinic), or arsenolite (As₂O₃, cubic), although a bona fide phase identification for each particle was not always possible. These phases occur predominantly as heteroaggregates. Multi-element single particle analyses demonstrate that Cr occurs as a pure phase (i.e., Cr oxides) as well as in association with other elements (e.g., Cu and As); Cu occurs predominantly in association with Cr and As; and As occurs as As oxides and in association with Cu and Cr. Several Cr, Cu, and As clusters were identified and the molar ratios of Cr/Cu and Cr/As within these clusters are consistent with the crystalline phases identified by TEM as well as their heteroaggregates. These results indicate that WUI fires can lead to significant release of CCA constituents and their combustion-transformed by-products into the surrounding environment. This study also provides a method to identify and track CCA constituents in environmental systems based on multi-element analysis using SP-ICP-TOF-MS.

Ecotoxic, genotoxic, and cytotoxic potential of leachate obtained from chromated copper arsenate-treated wood ashes

Preservative treatments increase the durability of wood, and one of the alternative treatments involves the use of chromated copper arsenate (CCA). Due to the toxicity of CCA, the disposal of CCA-treated wood residues is problematic, and burning is considered to provide a solution. The ecotoxicological potential of ash can be high when these components are toxic and mutagenic. The aim of this study was to evaluate the toxicity and genotoxicity of bottom ash leachates originating from CCA-treated wood burning. Physical-chemical analysis of the leachates revealed that in treated wood ashes leachate (CCA-TWBAL), the contents of arsenic and chromium were 59.45 mg.L^-1 and 54.28 mg.L^-1, respectively. In untreated wood ashes leachate (UWBAL), these contents were 0.70 mg.L^-1 and 0.30 mg.L^-1, respectively. CCA-TWBAL caused significant toxicity in Lactuca sativa, Allium cepa, and microcrustacean Artemia spp. (LC50 = 12.12 mg.mL^-1). Comet assay analyses using NIH3T3 cells revealed that concentrations ranging from 1.0 and 2.5 mg.mL^-1 increase the damage frequency (DF) and damage index (DI). According to MTT assay results, CCA-TWBAL at concentrations as low as 1 mg.mL^-1 caused a significant decrease in cellular viability. Hemolysis assay analyses suggest that the arsenic and chromium leachate contents are important for the ecotoxic, cytotoxic, and genotoxic effects of CCA-TWBAL.

Rosmarinus officinalis essential oil modulates renal toxicity and oxidative stress induced by potassium dichromate in rats

BACKGROUND

Chromium hexavalent (CrVI) is known as a toxic contaminant that induced oxidative stress and nephrotoxicity in humans and animals. Rosmarinus officinalis is a perennial herb rich in biologically active constituents that have powerful antioxidant properties. So, the current work evaluated the effectiveness of Rosmarinus officinalis essential oil (REO) against alterations induced by potassium dichromate in the kidney of male rats.

METHODS

GC-MS analysis, in vitro total phenol contents, and DPPH scavenging activity of REO were estimated. Thirty-five Wistar male rats were categorized into 5 groups. The first group was the control, the second one was orally administered rosemary essential oil (REO; 0.5 mL/kg BW), the third group was injected intraperitoneally with hexavalent chromium (CrVI; 2 mg/kg BW) for 14 days, the fourth group used as the protective group (REO was administrated 30 min before i.p. injection of CrVI) and the fifth group applied as the therapeutic group (rats injected with CrVI 30 min followed by oral administration of REO), respectively.

RESULTS

Twenty-nine components were detected with high total phenolic contents and high DPPH scavenging activity. Results revealed that CrVI- intoxicated rats showed a valuable increase in oxidative stress profile (TBARS and H₂O₂) and a notable decline in glutathione (GSH), total protein content, and enzymatic antioxidants (SOD, CAT, GPx, and GST). Furthermore, serum kidney functions biomarkers (urea, creatinine, and uric acid) were increased significantly. Also, the administration of CrVI showed histological and immunohistochemical (PCNA-ir) changes in rat kidney tissue. Otherwise, administration of REO pre or post-treatment with CrVI significantly restored most of the biochemical parameters in addition to improvement in kidney tissue architecture. Moreover, individual intake with REO exhibited an amendment in oxidative stress markers.

CONCLUSION

Conclusively, REO had a potential antioxidant capacity in ameliorating K₂Cr₂O₇-induced nephrotoxicity, especially in the protection group.

Environmental and Health Hazards of Chromated Copper Arsenate-Treated Wood: A Review

Copper chrome arsenate (CCA) water-borne solution used to be widely used to make timber highly resistant to pests and fungi, in particular, wood products designed for outdoor use. Nowadays, CCA is a restricted chemical product in most countries, since potential environmental and health risks were reported due to dermal contact with CCA residues from treated structures and the surrounding soil, as well as the contamination of soils. However, large quantities of CCA-treated timber are still in use in framings, outdoor playground equipment, landscaping, building poles, jetty piles, and fencing structures around the world, thus CCA remains a source of pollutants to the environment and of increasing toxic metal/metalloid exposure (mainly in children). International efforts have been dedicated to the treatment of materials impregnated with CCA, however not only does some reuse of CCA-treated timber still occur, but also existing structures are leaking the toxic compounds into the environment, with impacts on the environment and animal and human health. This study highlights CCA mechanisms and the documented consequences in vivo of its exposure, as well as the adverse environmental and health impacts.

Effects of Excess Cr3+ on Trace Element Contents in the Brain and Serum in Chicken

This study aimed to investigate the effects of chromic chloride (CrCl₃) on Ca, Mg, Mn, Fe, Cu, and Zn contents in the brain and serum of chicken. Seventy-two chickens were randomly divided into four groups and treated with different doses of CrCl₃ via drinking water: 0, 1/8, 1/4, and 1/2 LD₅₀ for 42 days. The contents of the elements were evaluated through inductively coupled plasma mass spectrometry. Results showed that Cr contents in the brain and serum were higher than those in the control groups, although no significant dose-dependent changes (P > 0.05) in brain of the Cr-treated groups were observed at 42 days. As exposure time was prolonged and CrCl₃ dosage was increased, Ca contents increased (P < 0.05). Mg and Cu contents in serum decreased; by contrast, Mg and Cu contents initially increased and then decreased in the brain. Fe and Zn contents in the serum increased; conversely, Fe and Zn contents in the brain decreased. CrCl₃ exposure did not significantly affect Mn contents at 14 or 28 days, but significantly decreased (P < 0.05) at 42 days. Therefore, excess Cr³⁺ intake can disrupt absorption and deposition of other trace elements in the brain and serum; the blood-brain barrier may prevent the accumulation of these elements in the brain exposed to CrCl₃.

Growth performance and oxidative damage in kidney induced by oral administration of Cr(III) in chicken

This study aimed to evaluate the effects of adding chromic chloride (CrCl3) in the drinking water of chickens. Hyland brown male chickens were randomly divided into four groups. Three groups orally received 1/2 LD50, 1/4 LD50, and 1/8 LD50 CrCl3mgkg(-1) body weight daily for 42d. The fourth group was treated with water. The chickens were sacrificed at 14, 28, and 42d post-treatment. The renal injury was examined through histological analysis, and kidney mass was determined. The effects on growth performance were assessed by measuring the weight of the body, chest muscles, and leg muscles. Oxidative damage was evaluated by determining the antioxidant defense levels in kidney homogenates. The body weight and the weight of tissues gained time-dependently, but significantly decreased compared with those in the control group (P<0.05) at the same exposure time. Administering Cr(3+) significantly increased the levels of malondialdehyde, glutathione, and hydrogen peroxide in the kidney compared with those in the control groups. Whereas, administering Cr(3+) reduced the activities of superoxide dismutase, catalase, glutathione peroxidase, and total an-tioxidant capacity compared with those in the control group (P<0.05) in a dose- and time-dependent manner. In conclusion, oral administration of CrCl3 decreases the growth performance of chickens, leads to the pathological lesions and affects nephritic antioxidant capacity in the kidney dose- and time-dependently.

Simultaneous exposure to multiple heavy metals and glyphosate may contribute to Sri Lankan agricultural nephropathy

BACKGROUND

Sri Lankan Agricultural Nephropathy (SAN), a new form of chronic kidney disease among paddy farmers was first reported in 1994. It has now become the most debilitating public health issue in the dry zone of Sri Lanka. Previous studies showed SAN is a tubulo-interstitial type nephropathy and exposure to arsenic and cadmium may play a role in pathogenesis of the disease.

METHODS

Urine samples of patients with SAN (N = 10) from Padavi-Sripura, a disease endemic area, and from two sets of controls, one from healthy participants (N = 10) from the same endemic area and the other from a non-endemic area (N = 10; Colombo district) were analyzed for 19 heavy metals and for the presence of the pesticide- glyphosate.

RESULTS

In both cases and the controls who live in the endemic region, median concentrations of urinary Sb, As, Cd, Co, Pb, Mn, Ni, Ti and V exceed the reference range. With the exception of Mo in patients and Al, Cu, Mo, Se, Ti and Zn in endemic controls, creatinine adjusted values of urinary heavy metals and glyphosate were significantly higher when compared to non-endemic controls. Creatinine unadjusted values were significant higher for 14 of the 20 chemicals studied in endemic controls and 7 in patients, compared to non-endemic controls. The highest urinary glyphosate concentration was recorded in SAN patients (range 61.0-195.1 μg/g creatinine).

CONCLUSIONS

People in disease endemic area exposed to multiple heavy metals and glyphosate. Results are supportive of toxicological origin of SAN that is confined to specific geographical areas. Although we could not localize a single nephrotoxin as the culprit for SAN, multiple heavy metals and glyphosates may play a role in the pathogenesis. Heavy metals excessively present in the urine samples of patients with SAN are capable of causing damage to kidneys. Synergistic effects of multiple heavy metals and agrochemicals may be nephrotoxic.

Mechanisms of kidney toxicity for chromium- and arsenic-based preservatives: potential involvement of a pro-oxidative pathway

Metals have been extensively used for the preservation of wood. Among metallic conservatives, mixtures of chromated copper arsenate (CCA) were thoroughly used. However, the release and consequent mobilization of such compounds by biota, may culminate in the exertion of toxic chemical effects. The present study intended to show the toxicological effects caused by arsenic (7.2 mg/kg body weight), chromium (10.2 mg/kg Cr body weight) and the commercial mixture CCA (7.2 mg/kg As body weight and 10.2 mg/kg Cr body weight) in mice, namely the oxidative stress response (catalase - CAT, glutathione peroxidase - GPx, and glutathione-S-transferases - GSTs), in kidney tissues. The determination of the tested parameters was performed after exposure; organisms were exposed, and then sacrificed at two distinct periods, namely 14 and 96 h after the administration of toxicants. Exposure to chromium and arsenic induced significant modifications in the redox state of the test organisms, evidenced by significant alterations in GSTs and GPx activities. No alterations were found concerning the activity of catalase. These findings showed that the chemical mixture used as household product may exert significant toxicological outcomes in exposed animals, such as rodents, conditioning their redox homeostasis and antioxidant response.

Local and systemic toxicity of nanoscale debris particles in total hip arthroplasty

Over the past 30 years joint replacement prostheses have been developed and refined to enhance durability and reproducibility. Total hip joint arthroplasty is being performed in an increasing number of younger patients; therefore orthopaedic surgeons seek implants with a longer life span. With regards to the progress of mechanical behaviour of the biomaterials used in an arthroplasty, little is known about the long-term biological effects of wear debris. Owing to the composition of the prostheses currently in use, systemic exposure to chromium (Cr), cobalt (Co), nickel (Ni) and aluminium (Al) alloys occurs as a result of the formation of metal wear nano-particles that are released both from metal-on-metal and polyethylene-on-metal bearings, resulting in a postoperative increase in metal ion levels at different organ sites. These particles circulate both locally and systemically, penetrate cell plasma membranes, bind to cellular proteins and enzymes and modulate cytokine expression. Their physiologic effects are poorly understood and their potential toxicity, hypersensitivity and carcinogenicity remain a cause for concern. In this article we will address the issue of whether these nanoscale degradation products are associated with adverse, clinically significant local or systemic toxicologic sequelae.

Toxicity of chromated copper arsenate: a study in mice

Chromated copper arsenate (CCA) was widespread used as a chemical wood preservative with application in the construction of playground equipment, fences, jetties, and naval. Environmental protection agency (EPA) had limited the use of CCA-treated wood on 2002, due to probable implications on both human and environmental health. Although this fact, several industries pursue the use of this product within their manufactories. In addition, the durability of this wood for 60 years, makes these treated products an hazard to the public health. In the present work, studies were explored exposing mice to CCA, during 14, 24, 48, and 96 h for the assessment of acute toxicity of CCA. Kidney and liver were removed, prepared for histology and for metalloid, and copper content evaluation by high resolution inductively coupled plasma mass spectroscopy. The histological results evidenced apparently normal structures for control animals and group exposed to As2O5. On the contrary, the renal sections of the animals treated with CCA revealed epithelium cells desquamation, hyaline, and granular casts in renal tubules lumen. Furthermore, high levels of arsenic were detected in the kidney of animals treated with CCA over 14 and 48 h, being significantly greater than controls. Although this approach underlines the potential hazard of CCA on some vital organs, further testing may be required to establish the impacts on other functions.

Association between As and Cu renal cortex accumulation and physiological and histological alterations after chronic arsenic intake

Arsenic (As) is one of the most abundant hazards in the environment and it is a human carcinogen. Related to excretory functions, the kidneys in humans, animal models or naturally exposed fauna, are target organs for As accumulation and deleterious effects. Previous studies carried out using X-ray fluorescence spectrometry by synchrotron radiation (SR-microXRF) showed a high concentration of As in the renal cortex of chronically exposed rats, suggesting that this is a suitable model for studies on renal As accumulation. This accumulation was accompanied by a significant increase in copper (Cu) concentration. The present study focused on the localization of these elements in the renal cortex and their correlation with physiological and histological As-related renal effects. Experiments were performed on nine male Wistar rats, divided into three experimental groups. Two groups received 100 microg/ml sodium arsenite in drinking water for 60 and 120 consecutive days, respectively. The control group received water without sodium arsenite (< 50 ppb As). For histological analysis, 5-mum-thick sections of kidneys were stained with hematoxylin and eosin. Biochemical analyses were used to determine concentrations of plasma urea and creatinine. The As and Cu mapping were carried out by SR-microXRF using a collimated white synchrotron spectrum (300 microm x 300 microm) on kidney slices (2 mm thick) showing As and Cu co-distribution in the renal cortex. Then, renal cortical slices (100 microm thick) were scanned with a focused white synchrotron spectrum (30 microm x 30 microm). Peri-glomerular accumulation of As and Cu at 60 and 120 days was found. The effects of 60 days of arsenic consumption were seen in a decreased Bowman's space as well as a decreased plasma blood urea nitrogen (BUN)/creatinine ratio. Major deleterious effects; however, were seen on tubules at 120 days of exposition. This study supports the hypothesis that tubular accumulation of As-Cu may have some bearing on the arsenic-associated nephrotoxicological process.