Displaying publications 1 - 20 of 57 in total

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  1. Bai VR, Vanitha G, Zainal Ariff AR
    Infect Control Hosp Epidemiol, 2013 Nov;34(11):1234-5.
    PMID: 24113615 DOI: 10.1086/673461
    Matched MeSH terms: Hazardous Substances
  2. Carnero A, Blanco-Aparicio C, Kondoh H, Lleonart ME, Martinez-Leal JF, Mondello C, et al.
    Carcinogenesis, 2015 Jun;36 Suppl 1(Suppl 1):S19-37.
    PMID: 26106138 DOI: 10.1093/carcin/bgv029
    Carcinogenesis is thought to be a multistep process, with clonal evolution playing a central role in the process. Clonal evolution involves the repeated 'selection and succession' of rare variant cells that acquire a growth advantage over the remaining cell population through the acquisition of 'driver mutations' enabling a selective advantage in a particular micro-environment. Clonal selection is the driving force behind tumorigenesis and possesses three basic requirements: (i) effective competitive proliferation of the variant clone when compared with its neighboring cells, (ii) acquisition of an indefinite capacity for self-renewal, and (iii) establishment of sufficiently high levels of genetic and epigenetic variability to permit the emergence of rare variants. However, several questions regarding the process of clonal evolution remain. Which cellular processes initiate carcinogenesis in the first place? To what extent are environmental carcinogens responsible for the initiation of clonal evolution? What are the roles of genotoxic and non-genotoxic carcinogens in carcinogenesis? What are the underlying mechanisms responsible for chemical carcinogen-induced cellular immortality? Here, we explore the possible mechanisms of cellular immortalization, the contribution of immortalization to tumorigenesis and the mechanisms by which chemical carcinogens may contribute to these processes.
    Matched MeSH terms: Hazardous Substances/adverse effects*
  3. Ta GC, Mokhtar MB, Peterson PJ, Yahaya NB
    Ind Health, 2011;49(6):765-73.
    PMID: 22020020
    The European Union (EU) and the World Health Organization (WHO) have applied different approaches to facilitate the implementation of the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The EU applied the mandatory approach by gazetting the EU Regulation 1272/2008 incorporating GHS elements on classification, labelling and packaging of substances and mixtures in 2008; whereas the WHO utilized a voluntary approach by incorporating GHS elements in the WHO guidelines entitled 'WHO Recommended Classification of Pesticides by Hazard' in 2009. We report on an analysis of both the mandatory and voluntary approaches practised by the EU and the WHO respectively, with close reference to the GHS 'purple book'. Our findings indicate that the mandatory approach practiced by the EU covers all the GHS elements referred to in the second revised edition of the GHS 'purple book'. Hence we can conclude that the EU has implemented the GHS particularly for industrial chemicals. On the other hand, the WHO guidelines published in 2009 should be revised to address concerns raised in this paper. In addition, both mandatory and voluntary approaches should be carefully examined because the classification results may be different.
    Matched MeSH terms: Hazardous Substances/classification*
  4. Wu Y, Liu Y, Kamyab H, Rajasimman M, Rajamohan N, Ngo GH, et al.
    Environ Res, 2023 Sep 01;232:116363.
    PMID: 37295587 DOI: 10.1016/j.envres.2023.116363
    Due to their widespread occurrence and detrimental effects on human health and the environment, endocrine-disrupting hazardous chemicals (EDHCs) have become a significant concern. Therefore, numerous physicochemical and biological remediation techniques have been developed to eliminate EDHCs from various environmental matrices. This review paper aims to provide a comprehensive overview of the state-of-the-art remediation techniques for eliminating EDHCs. The physicochemical methods include adsorption, membrane filtration, photocatalysis, and advanced oxidation processes. The biological methods include biodegradation, phytoremediation, and microbial fuel cells. Each technique's effectiveness, advantages, limitations, and factors affecting their performance are discussed. The review also highlights recent developments and future perspectives in EDHCs remediation. This review provides valuable insights into selecting and optimizing remediation techniques for EDHCs in different environmental matrices.
    Matched MeSH terms: Hazardous Substances/toxicity
  5. Karwowski MP, Morman SA, Plumlee GS, Law T, Kellogg M, Woolf AD
    Environ Geochem Health, 2017 Oct;39(5):1133-1143.
    PMID: 27704308 DOI: 10.1007/s10653-016-9881-6
    Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13-18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant's venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.
    Matched MeSH terms: Hazardous Substances/analysis; Hazardous Substances/blood
  6. Pakpahan EN, Isa MH, Kutty SR, Chantara S, Wiriya W
    Environ Technol, 2013 Jan-Feb;34(1-4):407-16.
    PMID: 23530354
    Petroleum sludge is a hazardous waste that contains various organic compounds including polycyclic aromatic hydrocarbons (PAHs) which have carcinogenic-mutagenic and toxic characteristics. This study focuses on the thermal treatment (indirect heating) of petroleum sludge cake for PAH degradation at 250, 450, and 650 degrees C using Ca(OH)2 + NaHCO3 as an additive. The treatment was conducted in a rotary drum electric heater. All experiments were carried out in triplicate. Concentrations of the 16 priority PAHs in gas (absorbed on Amberlite XAD-4 adsorbent), particulate (on quartz filter) and residue phases were determined using gas chromatography-mass spectrometry (GC-MS). The samples were extracted with acetonitrile by ultra-sonication prior to GC-MS analysis. The use of additive was beneficial and a temperature of 450 degrees C was suitable for PAH degradation. Low levels of PAH emissions, particularly carcinogenic PAH and toxic equivalent concentration (sigma TEC), were observed in gas, particulate and residue phases after treatment.
    Matched MeSH terms: Hazardous Substances*
  7. Ang TK, Safuan HM, Sidhu HS, Jovanoski Z, Towers IN
    Bull Math Biol, 2019 07;81(7):2748-2767.
    PMID: 31201660 DOI: 10.1007/s11538-019-00627-8
    The present paper studies a predator-prey fishery model which incorporates the independent harvesting strategies and nonlinear impact of an anthropogenic toxicant. Both fish populations are harvested with different harvesting efforts, and the cases for the presence and non-presence of harvesting effort are discussed. The prey fish population is assumed to be infected by the toxicant directly which causes indirect infection to predator fish population through the feeding process. Each equilibrium of the proposed system is examined by analyzing the respective local stability properties. Dynamical behavior and bifurcations are studied with the assistance of threshold conditions influencing the persistence and extinction of both predator and prey. Bionomic equilibrium solutions for three possible cases are investigated with certain restrictions. Optimal harvesting policy is explored by utilizing the Pontryagin's Maximum Principle to optimize the profit while maintaining the sustainability of the marine ecosystem. Bifurcation analysis showed that the harvesting parameters are the key elements causing fishery extinction. Numerical simulations of bionomic and optimal equilibrium solutions showed that the presence of toxicant has a detrimental effect on the fish populations.
    Matched MeSH terms: Hazardous Substances/toxicity
  8. Adira Wan Khalit WN, Tay KS
    Environ Sci Process Impacts, 2016 May 18;18(5):555-61.
    PMID: 27062128 DOI: 10.1039/c6em00017g
    Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and free available chlorine (FAC) was determined at 25 ± 0.1 °C. The result indicated that the degradation of Mfe by FAC is highly pH-dependent. When the pH was increased from 6 to 8, it was found that the kapp for the reaction between Mfe and FAC was decreased from 16.44 to 4.4 M(-1) s(-1). Characterization of the transformation by-products formed during the chlorination of Mfe was carried out using liquid chromatography-quadrupole time-of-flight accurate mass spectrometry. Four major transformation by-products were identified. These transformation by-products were mainly formed through hydroxylation, chlorination and oxidation reactions. Ecotoxicity assessment revealed that transformation by-products, particularly monohydroxylated Mfe which is more toxic than Mfe, can be formed during aqueous chlorination.
    Matched MeSH terms: Hazardous Substances/chemistry*
  9. Tan CC
    Scand J Work Environ Health, 1991 Aug;17(4):221-30.
    PMID: 1925433
    Nurses are an integral component of the health care delivery system. In discharging their duties, nurses encounter a variety of occupational health problems which may be categorized into biological hazards, chemical hazards, physical hazards, and psychosocial hazards. A review of some examples of each of these four types of hazards is presented in this article. Particular attention has been devoted to hepatitis B, acquired immunodeficiency syndrome, tuberculosis, cytotoxic drugs, anesthetic agents, needlestick injury, back pain, and stress.
    Matched MeSH terms: Hazardous Substances/adverse effects
  10. Karami R, Mohsenifar A, Mesbah Namini SM, Kamelipour N, Rahmani-Cherati T, Roodbar Shojaei T, et al.
    PMID: 26503886
    Organophosphorus (OP) compounds are one of the most hazardous chemicals used as insecticides/pesticide in agricultural practices. A large variety of OP compounds are hydrolyzed by organophosphorus hydrolases (OPH; EC 3.1.8.1). Therefore, OPHs are among the most suitable candidates which could be used in designing enzyme-based sensors for detecting OP compounds. In the present work, a novel nanobiosensor for the detection of paraoxon was designed and fabricated. More specifically, OPH was covalently embedded onto chitosan and the enzyme-chitosan bioconjugate was then immobilized on negatively charged gold nanoparticles (AuNPs) electrostatically. The enzyme was immobilized on AuNPs without chitosan as well to compare the two systems in terms of detection limit and enzyme stability under different pH and temperature conditions. Coumarin 1, a competitive inhibitor of the enzyme, was used as a fluorogenic probe. The emission of coumarin 1 was effectively quenched by the immobilized Au-NPs when bound to the developed nanobioconjugates. However, in the presence of paraoxon, coumarin 1 left the nanobioconjugate leading to enhanced fluorescence intensity. Moreover, compared to the immobilized enzyme without chitosan, the chitosan-immobilized enzyme was found to possess decreased Km value by over 50%, increased Vmax and Kcat values by around 15% and 74%, respectively. Higher stability within a wider range of pH (2-12) and temperature (25-90°C) was also achieved. The method worked in the 0 to 1050 nM concentration ranges, and had a detection limit as low as 5 × 10(-11) M.
    Matched MeSH terms: Hazardous Substances
  11. Zango ZU, Jumbri K, Sambudi NS, Ramli A, Abu Bakar NHH, Saad B, et al.
    Polymers (Basel), 2020 Nov 10;12(11).
    PMID: 33182825 DOI: 10.3390/polym12112648
    Water-borne emerging pollutants are among the greatest concern of our modern society. Many of these pollutants are categorized as endocrine disruptors due to their environmental toxicities. They are harmful to humans, aquatic animals, and plants, to the larger extent, destroying the ecosystem. Thus, effective environmental remediations of these pollutants became necessary. Among the various remediation techniques, adsorption and photocatalytic degradation have been single out as the most promising. This review is devoted to the compilations and analysis of the role of metal-organic frameworks (MOFs) and their composites as potential materials for such applications. Emerging organic pollutants, like dyes, herbicides, pesticides, pharmaceutical products, phenols, polycyclic aromatic hydrocarbons, and perfluorinated alkyl substances, have been extensively studied. Important parameters that affect these processes, such as surface area, bandgap, percentage removal, equilibrium time, adsorption capacity, and recyclability, are documented. Finally, we paint the current scenario and challenges that need to be addressed for MOFs and their composites to be exploited for commercial applications.
    Matched MeSH terms: Hazardous Substances
  12. Keat CH, Sooaid NS, Yun CY, Sriraman M
    Asian Pac J Cancer Prev, 2013;14(1):69-73.
    PMID: 23534806
    BACKGROUND: An increasing trend of cytotoxic drug use, mainly in cancer treatment, has increased the occupational exposure among the nurses. This study aimed to assess the change of nurses' safety-related knowledge as well as attitude levels and subsequently to assess the change of cytotoxic drug handling practices in wards after a series of pharmacist-based interventions.

    MATERIALS AND METHODS: This prospective interventional study with a before and after design requested a single group of 96 nurses in 15 wards actively providing chemotherapy to answer a self-administered questionnaire. A performance checklist was then used to determine the compliance of all these wards with the recommended safety measures. The first and second assessments took 2 months respectively with a 9-month intervention period. Pharmacist-based interventions included a series of technical, educational and administrative support measures consisting of the initiation of closed-system cytotoxic drug reconstitution (CDR) services, courses, training workshops and guideline updates.

    RESULTS: The mean age of nurses was 32.2∓6.19 years. Most of them were female (93.8%) and married (72.9%). The mean knowledge score of nurses was significantly increased from 45.5∓10.52 to 73.4∓8.88 out of 100 (p<0.001) at the end of the second assessment. Overall, the mean practice score among the wards was improved from 7.6∓5.51 to 15.3∓2.55 out of 20 (p<0.001).

    CONCLUSIONS: The pharmacist-based interventions improved the knowledge, attitude and safe practices of nurses in cytotoxic drug handling. Further assessment may help to confirm the sustainability of the improved practices.

    Matched MeSH terms: Hazardous Substances/toxicity*
  13. Kassim A, Halmi MIE, Gani SSA, Zaidan UH, Othman R, Mahmud K, et al.
    Ecotoxicol Environ Saf, 2020 Jun 15;196:110527.
    PMID: 32278138 DOI: 10.1016/j.ecoenv.2020.110527
    Assessment of eco-toxicant using bioluminescent bacterial assay is a widely used and globally accepted method. In this work, a new luminescent bacterium was isolated from squid (Loligo duvauceli) and identified as Photobacterium leiognathi strain AK-MIE using 16S rRNA, phylogeny analysis. The predicted optimum conditions by RSM were 2.76% (w/v) NaCl, 2.28% (w/v) peptone, 0.34% (w/v) yeast extract, and pH 6.83 with 541,211.80 RLU of luminescent production whereas the predicted optimum conditions by ANN were 2.21% (w/v) NaCl, 2.27% (w/v) peptone, 0.39% (w/v) yeast extract, and pH 6.94 which produced 541,986.20 RLU. The validation analysis of both RSM and ANN show 0.60% and 0.69% deviation from the predicted results indicating that both models provided good quality predictions with ANN showing a superior data fitting capability for non-linear regression analysis. Toxicity tests show strain AK-MIE was sensitive to mercury (concentration causing 50% inhibition or IC50 of 0.00978 mgL-1), followed by cadmium (IC50 of 0.5288 mgL-1), copper IC50 of (0.8117 mgL-1), silver (IC50 of 1.109 mgL-1), and lead (IC50 of 10.71 mgL-1) which are more sensitive than previously isolated luminescent bacteria, suggesting that strain AK-MIE has the potential to be used in toxicity assessment of heavy metals in the environment. Based on the field trial results, several sediment samples from industrial areas in Bangi, Selangor managed to inhibit the bioluminescence of strain AK-MIE. Validation method carried out using ICP-MS proved the presence of several toxic heavy metal elements.
    Matched MeSH terms: Hazardous Substances/analysis*; Hazardous Substances/toxicity
  14. Ahmad Zaimi Mohd Zawawi, Shazatul Izzati Sha’aree
    MyJurnal
    Termites encompass a various range of destruction of crops and capable of decomposing woods. The widely being used of hazardous chemical pesticides has develop many health problems to the users. Hence, the aim of this study was to substitute the use of hazardous chemical pesticides to herbs based pesticides as repellent agent against rubber termites (Coptotermes curvignathus), which is safer and easier to use. The selected herbs species for this study are lemongrass (Cymbopogon citratus), garlic (Allium sativum) and wild mint (Mentha arvensis). As for C.curvignathus, they were obtained from Forest Research Institute Malaysia (FRIM), Kepong, Selangor, Malaysia. Khaya wood (Khaya senegalensis) (3cm x 2cm x 2cm) is the woods sample that being used. All woods samples were treated with all the selected herbs extract. The repellent testing was conducted for 21 days. The result obtained showed that the three herbs were effective to be used as repellent when compared to percentage weight loss of control, which is 23.58%. The percentages of weight loss of treated groups using aqueous extraction of herbs were 0.61% (lemongrass), 1.56% (mint), and 1.72% (garlic), whereas for methanol extraction of herbs were 0.52% (lemongrass), 1.13% (mint) and 1.55% (garlic). From Analysis of Variance (ANOVA), there is significant different in mean among group with F=275.49, p- value=0.000
    Matched MeSH terms: Hazardous Substances
  15. Muhammad Firdaus Othman,, Nor Aimi Abdul Wahab, Suhaiza Hasan, Marina Mokhtar, Noorezal Atfyinna Mohd Napiah, Mohd Noor Mokhtar, et al.
    Jurnal Inovasi Malaysia, 2019;2(2):123-139.
    MyJurnal
    Teaching, learning and reseach activities in chemical laboratory usually involves a variety of hazardous chemicals. All chemicals stored in the laboratories should be accompanied by a safety data sheet which contains information such as chemical composition, safety precautions for handling and storing chemicals and emergency measures in case of accident. Ineffective management of chemical safety data sheet makes it difficult to access and resulting in slow action taken in the event of accident. To overcome this problem, Quisy-SDS was introduced to ensure a more effective chemical safety information management. Quisy-SDS provides a convenient method for all lab users and emergency respondents to acess the chemical safety information. This method uses a Quick Response (QR) code and website that allow users to acess the information in no time, anytime and anywhere. The use of Quisy-SDS has successfully reduced the search time of chemical safety information by 98% compared to the previous method.
    Matched MeSH terms: Hazardous Substances
  16. Singh RB, Patra KC, Pradhan B, Samantra A
    J Environ Manage, 2024 Feb 14;352:120091.
    PMID: 38228048 DOI: 10.1016/j.jenvman.2024.120091
    Water is a vital resource supporting a broad spectrum of ecosystems and human activities. The quality of river water has declined in recent years due to the discharge of hazardous materials and toxins. Deep learning and machine learning have gained significant attention for analysing time-series data. However, these methods often suffer from high complexity and significant forecasting errors, primarily due to non-linear datasets and hyperparameter settings. To address these challenges, we have developed an innovative HDTO-DeepAR approach for predicting water quality indicators. This proposed approach is compared with standalone algorithms, including DeepAR, BiLSTM, GRU and XGBoost, using performance metrics such as MAE, MSE, MAPE, and NSE. The NSE of the hybrid approach ranges between 0.8 to 0.96. Given the value's proximity to 1, the model appears to be efficient. The PICP values (ranging from 95% to 98%) indicate that the model is highly reliable in forecasting water quality indicators. Experimental results reveal a close resemblance between the model's predictions and actual values, providing valuable insights for predicting future trends. The comparative study shows that the suggested model surpasses all existing, well-known models.
    Matched MeSH terms: Hazardous Substances
  17. Hayyan M, Hashim MA, Hayyan A, Al-Saadi MA, AlNashef IM, Mirghani ME, et al.
    Chemosphere, 2013 Feb;90(7):2193-5.
    PMID: 23200570 DOI: 10.1016/j.chemosphere.2012.11.004
    In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required.
    Matched MeSH terms: Hazardous Substances/toxicity*
  18. Premalatha GD, Ravindran J
    Med J Malaysia, 2000 Mar;55(1):146-51; quiz 152.
    PMID: 11072503
    The number of women in the workforce in increasing. A substantial proportion are in the reproductive age which brings to attention the problem of work exposures that adversely affect reproductive outcome. These exposures include chemicals, radiation, strenuous physical activity and infections. They affect reproduction by effect on the germ cells, through hormonal distribution which in turn affects transport of germ cells or zygote, implantation and development. Some of these exposures are teratogenic. At present, some regulations and policies seem to be directed at women workers while there is evidence to show that women are not the only victims. Paternal exposures have also been reported to be associated with infertility, spontaneous abortions and other adverse outcomes. There is insufficient information about reproductive effects of work exposures and hence further research is required in this area.
    Matched MeSH terms: Hazardous Substances/adverse effects
  19. Rahim, Z.H.A.
    Ann Dent, 1998;5(1):-.
    MyJurnal
    Saliva collection is non-invasive and less stressful when compared with blood collection. Extensive studies on saliva has been carried out and the use of saliva as a biological sample in clinical diagnosis and for monitoring hormones, drugs and pollutants and viruses has been recommended. The complexities associated with saliva such as proper collection device and strict standardisation of a number of factors which include time of collection, types of saliva and storage made it less favourable to blood.
    Matched MeSH terms: Hazardous Substances
  20. Ghaffari Khaligh N, Mihankhah T, Titinchi S, Shahnavaz Z, Rafie Johan M
    Turk J Chem, 2020;44(4):1100-1109.
    PMID: 33488215 DOI: 10.3906/kim-2005-6
    This work introduces a new additive named 4,4'-trimethylenedipiperidine for the practical and ecofriendly preparation of ethyl 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate derivatives. This chemical is commercially available and easy to handle. It also possesses a low melting point and a broad liquid range temperature, high thermal stability, and good solubility in water. Based on green chemistry principles, the reaction was performed in a) a mixture of green solvents i.e. water and ethanol (1:1 v/v) at reflux temperature, and b) the additive was liquefied at 65 °C and the reaction was conducted in the liquid state of the additive. High yields of the desired triazolo-pyrimidines were obtained under both aforementioned conditions. Our results demonstrated that this additive, containing 2 Lewis base sites and able to act as an acceptor-donor hydrogen bonding group, is a novel and efficient alternative to piperidine, owing to its unique properties such as its reduced toxicity, nonflammable nature, nonvolatile state, broad liquid range temperature, high thermal stability, and ability to be safely handled. Furthermore, this additive could be completely recovered and exhibited high recyclability without any change in its chemical structure and no significant reduction in its activity. The current methodology has several advantages: (a) it avoids the use of hazardous materials, as well as toxic, volatile, and flammable solvents, (b) it does not entail tedious processes, harsh conditions, and the multistep preparation of catalysts, (c) it uses a metal-free and noncorrosive catalyst, and (d) reduces the generation of hazardous waste and simple work-up processes. The most important result of this study is that 4,4'-trimethylenedipiperidine can be a promising alternative for toxic, volatile, and flammable base reagents in organic synthesis owing to its unique properties.
    Matched MeSH terms: Hazardous Substances
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