Environmental analysis, health and toxicology最新文献

TiO2 have been studied on inhalation and skin exposure due to the properties of the materials' use (cosmetics, paints and other products) and the additional safety information on other intake routes for the potential risk assessment is limited. The aim of this study was to obtain dose-range for subchronic study (repeated 90-day dermal toxicity) new TiO2 powder, GST produced through sludge recycling of the sewage treatment plant through repeated-dose toxicity in Sprague-Dawley (SD) rats. Three test groups for the GST were administered at 500, 1000, 2000 mg/kg B.W/day in addition to a control group (distilled water for injection). 5 male and 5 female rats were included in each group, and we examined the clinical signs, body weights, food consumption, necropsy (organ weights, macroscopic findings), hematological / biochemical parameters and histopathological findings (eye, skin). As a result of observations, there were no treatment-related effects including clinical signs, mortality, necropsy findings etc. Therefore, the present results suggest that the TiO2-related effects were not observed for dermal during 28-day and dose selection for repeated 90-day study was considered to be 500, 1000 and 2000 mg/kg B.W/day under the present study conditions.

TiO2 have been studied on inhalation and skin exposure due to the properties of the materials' use (cosmetics, paints and other products) and the additional safety information on other intake routes for the potential risk assessment is limited. Therefore, the aim of this study was to obtain safety data for new TiO2 powder, GST produced through sludge recycling of the sewage treatment plant through repeated-dose toxicity in Sprague-Dawley (SD) rats in according to the OECD test guideline (TG 408). Based on the results of the dose-range finding study (28-day repeated toxicity), GST was orally administered to rats at doses of 0, 500, 1000, and 2000 mg/kg B.W/day for 90-day and reversibility of effects of 2000 mg/kg bw/day was assessed after 4 weeks. In clinical signs, compound-colored stool was observed in all animals of treatment group (low: day 14 or 15, middle: day 8, high: day 8) and continuously observed up to the end of administration or day 1 of recovery period (high dose group). Also, the test substance retention in gastro-intestinal tract was observed in all animals of treatment group in gross finding at necropsy and foreign materials in lumen of these organs (stomach, duodenum, ileum, cecum, colon, rectum) likely indicative for the presence of test material in histopathological examination. In addition, no test substance-related adverse effects were noted in the detailed clinical observations, sensory reactivity/ functional assessments, body weight, food consumption, urinary analysis, ophthalmological examination, hematological / biochemical parameters, organ weights, histopathological findings. Therefore, the present results show that the NOAEL (no observed adverse effect level) of new TiO2 powder, GST was considered to be 2000 mg/kg B.W/day in rats after repeated oral administration for 90-day under the present study conditions and no target organs were identified.

Lead exposure has been linked to health challenges involving multiple organ failure. More than fifty percent of lead present in the human body is accumulated in the liver causing hepatic injury. A major mechanism of lead toxicity is oxidative stress. TrévoTM is a nutritional supplement with numerous bioactive natural products with detoxifying and antioxidant properties. This study was designed to investigate the hepatoprotective effects of TrévoTM dietary supplements against lead-hepatotoxicity in male Wistar rats. Thirty-five healthy animals were divided into five groups of seven each as follows: Group I=control; II=15 mg/kg of lead acetate (PbA); III= 2 mL/kg of TrévoTM + PbA; IV= 5 mL/kg of TrévoTM + PbA;V=5 mL/kg of TrévoTM . Animals were orally treated with TrévoTM for two days before co-administration with PbA intraperitoneally for 12 consecutive days. Animals were sacrificed 24 h after the last administration and blood were collected via cardiac puncture and processed for hematological parameters and assessment of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB). The liver was excised and processed for markers of oxidative stress and histopathological examination. Intraperitoneal administration of 15 mg/kg of PbA caused a significant increase in serum concentration of AST, ALT, while the concentration of ALB was significantly decreased (Plt;0.001). PbA caused a significant reduction in packed cell volume, hemoglobin while the total white blood cell count, neutrophils, lymphocytes, monocytes, eosinophils, and basophils were increased. Oxidative stress was significantly pronounced in the liver of rats exposed to PbA as observed in the high concentration of malonedialdehyde, decreased concentration of glutathione, the activity of catalase, superoxide dismutase, and glutathione-S-transferase. Pretreatment with TrévoTM was able to significantly prevent the anemic, oxidative damage, and hepatic injury initiated by PbA. Histological examination also corroborated the biochemical results. In conclusion, the study reveals that TrévoTM is effective in attenuating PbA-induced hepatotoxicity in male Wistar rats.

Microbe-plant partnership in phytoremediation involves a synergistic interaction that leads to degradation of contaminants. The identification and characterization of these microorganisms is fundamental in environmental management. This study is aimed at investigating the influence of Glycine max and Zea mays on microbial make-up and differentiation of soil bacterial and fungal isolates in crude oil contaminated soil. We employed conventional technique of microbial isolation and gene sequencing to evaluate the microbial composition in crude oil contaminated soil. The microorganisms were isolated from crude oil contaminated soil (0%, 4%, 8%) and were identified using 16S rRNA gene (for bacteria) and Internal Transcribed Spacer (ITS) gene (for fungi). We observed a change in the microbial cell density with respect to treatment conditions implying a shift in microbial dynamics to total hydrocarbon utilizing bacteria as the dominant microbes. The sequence data revealed five bacteria strain; Klebsiella aerogenes strain 77, Klebsiella aerogenes strain UISO178, Salmonella enterica strain ABUH7, Klebsiella aerogenes strain M242 and Enterobacter sp. NCCP-607 and three fungi strains; Galactomyces geotrichum strain CBS, Aspergillus niger strain YMCHA73 and Trichoderma virens isolate A701. Annotation analysis using FGENESB and gene scan revealed proteins involved in various metabolic processes and hydrocarbon utilization. GHOSTKOLA output revealed several genetic elements and pathways such as DnaA, PYG, mrcA, environmental, cellular and genetic information processing and degradation enhancers. Our findings show that G. max and Z. mays in association with bacteria can enhance ecosystem restoration of crude oil contaminated soil.

Pesticides notwithstanding their benefits in agriculture pose threats to non-target fauna such as amphibians. This study examined the avoidance responses of tadpoles of the African common toad, Amietophrynus regularis, exposed to Dichlorvos and Paraquat under a non-forced multi-compartmented exposure system (NFS) and estimated the Population Immediate Decline (PID) by integrating avoidance and lethal responses. The NFS was designed to allow the free movement of tadpoles across six compartments in order to elucidate the ability of aquatic organisms to detect and potentially avoid contaminated environments at will. The tadpoles (n=3 per compartment/concentration; 18 per system) were exposed to gradients of Dichlorvos (0, 0.3, 0.5, 0.7, 1.0 and 2.0 mg/L) and Paraquat (0, 1.0, 5.0, 10.0, 15.0, and 20.0 mg/L) in quadruplicates with their distribution recorded every 20 mins for 3 h. 48 h acute toxicity tests under forced exposure system (FS) was performed using the same range of concentrations. Acute toxicity (48 h) response in the FS tests was dose dependent with LC50 values of 0.79 mg/L and 6.46 mg/L recorded for Dichlorvos and Paraquat, respectively. The mean percentage distribution of tadpoles recorded for Dichlorvos and Paraquat was about 11% and 0% in the highest concentrations (2.0 and 20.0 mg/L) to 58% and 69% in compartments with no contaminants (control), respectively. PID was primarily driven by avoidance responses rather than mortality. These findings are of conservation interest as it elucidates the potential of both pesticides to impair local distribution of amphibians and cause biodiversity loss.

This cross-sectional study was aimed at assessing the exposure to organic solvents and the factors affecting prevalence of neurological symptoms among workers at gas stations in Rayong Province. The sample included 200 workers at gas stations, including refueling staff, cashiers, food shop, coffee shop, and convenience store employees. Interview questionnaire included general information, work history, and neurological symptoms. Urine collection devices were used to detect organic solvents metabolized in urine, including t,t-muconic acid (t,t-MA), hippulic acid (HA), mandelic acid (MA), and methylhppuric acid (MHA).The results showed that the workers' medians (interquartile range: IQR) of the metabolized organic solvents were as follows: t,t-MA was 393.62 (244.59) µg/g Cr, HA was 0.32 (0.14) g/g Cr, MA was 0.06 (0.02) g/g Cr, and MHA was 0.40 (0.13) g/g Cr. For prevalence of neurological symptoms, top three symptoms were headache (49.0%), dizziness (42.5%), and stress/irritability (38.5%). Working at a gas station present was neurological symptoms more than in the past was 32.5%. According to the assessment of exposure to metabolized organic solvents and factors affecting the prevalence of neurological symptoms, overtime work ≥ 6 hours and HA content greater than quartiles Q3 had an effect on neurologic symptoms (OR=2.17; 95%CI=1.23-5.10 and OR=2.15; 95%CI=1.18- 4.76, respectively). In summary, time spent working in gas stations and exposure to toluene organic solvents can cause neurological symptoms. It is recommended to reduce overtime or add breaks during work shifts or shift changes. In addition, workers should be away from the solvent.

Microplastics have become a significant environmental concern. However, information on toxicity of microplastics in terrestrial organisms is limited. In this study, the chronic toxic effects of polystyrene microplastics (PS-MPs) on the reproductive system and serum antioxidants of male albino Wistar rats fed for 90 days with standard rat feed containing 1-10% granules of crushed polystyrene disposable plates were evaluated. Significant reductions in volume, motility, epididymal sperm count and serum testosterone level were observed. Histological examination of testicular architecture showed distorted testes with vacuolated seminiferous tubules at the highest percentage, together with increased catalase and decreased superoxide dismutase activities. This study showed that ingestion of PS-MPs caused reproductive dysfunction in male rats and contributes to understanding the potential toxicity of microplastics in terrestrial animals.

Air quality has critical public health impacts as several diseases have been attributed to exposure to high PM2.5 concentrations. In the Kingdom of Bahrain context, while the sources of PM2.5 and prevailing trends have been studied, its social and health dimensions remain a gap in the literature. This study explores public perceptions of PM2.5 in the Kingdom of Bahrain, focusing especially on public awareness of PM2.5, its sources, and its health impacts. It further highlights actions taken by individuals to mitigate associated health impacts. This cross sectional study was based on the Driver-Pressure-State-Impact-Response framework. A self-administered questionnaire was distributed to the public, a total sample size of 263 responses. Descriptive statistics, including frequencies and percentages of participants' responses, were calculated. The Independent Samples t-test and a one-way analysis of variance (ANOVA) were applied along with the Chi-Square test to identify factors associated with the public's knowledge and practices relating to PM2.5 in Bahrain. A p-value of less than 0.05 was considered as statistically significant. A significant proportion of the participants were unaware of PM2.5, its concentration in Bahrain, and whether it is being measured. However, the majority of respondents had respiratory problems and took self-protective measures when the air quality was bad. There were statistically significant differences in the adoption of precautionary measures, which was prevalent among participants suffering from respiratory problems. Around 32% of the respondents were willing to pay monthly contributions to improve air quality and indicated their interest in receiving information on Bahrain's air quality via social and mass media. The findings suggest that there is a need to raise public awareness towards air pollution and its health effects. Moreover, epidemiological studies should be conducted to advance understanding on how air pollution is linked to morbidity and mortality in Bahrain.

Although fluorides are essential for dental health, there are growing health concerns regarding the risk-benefit ratio of fluoride exposure. The objectives of the study were to obtain data on the amount and human health risks of fluoride in drinking groundwater, as well as to compare and evaluate the differences in the outputs obtained by two different approaches in health risk assessment (deterministic vs probabilistic). From a densely populated industrial area of north-eastern Bosnia and Herzegovina, a total of 54 groundwater samples were collected. Fluoride concentrations varied from 1.69 to 3.52 mg/L. The WHOapos;s threshold value for fluoride in drinking water was exceeded in all the samples analysed, indicating an increased daily intake of fluoride from groundwater. Deterministic and semi-probabilistic techniques were used for exposure assessment and health risk quantification. Generally, the deterministic approach resulted in acceptable health risks in most adult exposure scenarios. However, the Monte Carlo simulation revealed that 20.6, 20.8, and 99.8% of adult males, females, and children, respectively, were above the tolerable upper intake level, indicating that both adults and children face a significant health risk. Nevertheless, small children are more vulnerable to environmental hazards than youth and adults. Hence, a more in-depth risk-benefit analysis is required to reduce/or optimize fluoride content in drinking water to prevent tooth decay and fluorosis at all ages. Considering that optimal daily intake of fluorides is a crucial factor for preserving human health, decision-makers should take steps to emphasize the importance of continuous monitoring of fluoride concentrations in drinking water.

Nitro-aromatics are listed in carcinogenic, teratogenic, and mutagenic compounds list. p- nitro-aniline is one of them used as a precursor of various chemical compounds in many industries like dyes, drugs, paints and several others. These are mostly given out as an effluent in rivers, lakes or open passage of land which exert several hazards to living creatures and environment. Some of the organic compounds are stable in alkaline condition and persist longer in environment. Very few reports are elaborating bio-remediation in alkaline condition using different hydrocarbons. This study was planned to elaborate mechanism of detoxification and searching the potential of decontamination of p-nitro-aniline in alkaline condition by experimental microbial strain. The bacterial strain pseudomonas DL17 was isolated from alkaline Lake Lonar, Buldana, (MS.) India; and employed in this experiment considering its indigenous property to tolerate the alkaline pH. It also showed resistance to p-nitro-aniline with its raising concentrations on testing after adaptation. The experimental microbial stain showed 100% biodegradation of (500 mg/L) p-nitro-aniline within 48h. On shaking incubator with 110 rpm and at 32 °C optimum temperature. The centrifugate obtained after spinning at 10,000 g by cold centrifuge was used for solvent extraction. Generally, ethyl acetate or DCM was used for solvent extraction. The estimation of residual remains of p-nitro aniline by 6h. intervals was carried after removal of flasks from shaking incubator and centrifugation. At the optimum temperature and pH experiments were carried after knowing the resistance to experimental contaminant range (100-400 mg/L) of p-nitro aniline one month and further extended to 500 mg/L for 15days more. The residual metabolites were purified by column chromatography and various spectrometric studies such as UV-Vis spectroscopy, HNMR, FTIR and GCMS revealed that p-Phenylenediamine, acetanilide, aniline, acetaminophen, catechol, p-bezoquinone, cis-cis muconate as a metabolites. On the basis of the metabolites isolated and characterized by different spectroscopic studies the bio-catalytic mechanism was deduced. The induced enzymes such as nitroreductase, catalase, peroxidase, acetanilide hydroxylase, super oxide dismutase, catechol 1, 2 dioxygenase, catechol 2, 3 dioxygenase has commercial importance in biochemical industries. Induction of such biotransformation enzymes and consumption of p-nitro aniline concentration in experiments makes sure that this microbial strain pseudomonas DL17 can be employed for decontamination of nitro aniline polluted sites as well as isolation of such metabolites characterized and enzymes studied.