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Fulltext Respiratory Symptoms Among Domestic Waste Collectors

Salvaraji L, Jeffree MS, Avoi R, Akhir HM, Rahim SSSA, Lukman KA

Medeni Med J, 2020;35(4):304-309.
PMID: 33717622 DOI: 10.5222/MMJ.2020.82246

Objective: Increasing amount of waste concurrently increases the risk of exposure to hazardous materials among waste collectors. Vigorous exertion in the field intensifies the abundance of contaminated inspirable droplets. If left undetected and untreated, it may provoke significant pernicious health effects and redundant burdens to employees and employers. The purpose of this study is to determine the prevalence of respiratory symptoms and their associated factors among domestic waste collectors.
Method: A cross-sectional study was conducted in Kota Kinabalu, Sabah between January and April 2020. Data were collected using a validated questionnaire which encompasses details about sociodemographic, health status, environment, and employment characteristics.
Results: A total of 290 waste collectors with a mean age of 40 (±9) years old were participated in the study. Most of them were from Kadazan-Dusun-Murut ethnic origin with educational background till secondary school. The average monthly income of the workers was USD 298.45 (±171.9) per month, and they had been in service for 11 (±9.04) years. Respiratory symptoms were seen in 21% of the workers. The identified significant risk factors were determined as underlying chronic diseases (OR=2.34; 95% CI=1.054, 5.219) and contact with pets (OR=1.87; 95% CI=1.004, 3.288).
Conclusion: Respiratory symptoms are prevalent amidst domestic waste collectors and related to their health and field activities.

Matched MeSH terms: Hazardous Substances
Abatement of hazardous materials and biomass waste via pyrolysis and co-pyrolysis for environmental sustainability and circular economy

Chew KW, Chia SR, Chia WY, Cheah WY, Munawaroh HSH, Ong WJ

Environ Pollut, 2021 Mar 01;278:116836.
PMID: 33689952 DOI: 10.1016/j.envpol.2021.116836

The remarkable journey of progression of mankind has created various impacts in the form of polluted environment, amassed heavy metals and depleting resources. This alarming situation demands sustainable energy resources and approaches to deal with these environmental hazards and power deficit. Pyrolysis and co-pyrolysis address both energy and environmental issues caused by civilization and industrialization. The processes use hazardous waste materials including waste tires, plastic and medical waste, and biomass waste such as livestock waste and agricultural waste as feedstock to produce gas, char and pyrolysis oil for energy production. Usage of hazardous materials as pyrolysis and co-pyrolysis feedstock reduces disposal of harmful substances into environment, reducing occurrence of soil and water pollution, and substituting the non-renewable feedstock, fossil fuels. As compared to combustion, pyrolysis and co-pyrolysis have less emission of air pollutants and act as alternative options to landfill disposal and incineration for hazardous materials and biomass waste. Hence, stabilizing heavy metals and solving the energy and waste management problems. This review discusses the pyrolysis and co-pyrolysis of biomass and harmful wastes to strive towards circular economy and eco-friendly, cleaner energy with minimum waste disposal, reducing negative impact on the planet and creating future possibilities.

Matched MeSH terms: Hazardous Substances
Fulltext New protocols for the synthesis of 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate esters using an efficient additive

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
Fulltext EVALUATION OF SELECTED HERBS EXTRACT AS REPELLENT AGAINST RUBBER TERMITES (Coptotermes curvignathus)

Ahmad Zaimi Mohd Zawawi, Shazatul Izzati Sha’aree

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):85-90.
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
Development, formulation and optimization of a novel biocompatible ionic liquids dispersant for the effective oil spill remediation

Baharuddin SH, Mustahil NA, Reddy AVB, Abdullah AA, Mutalib MIA, Moniruzzaman M

Chemosphere, 2020 Jun;249:126125.
PMID: 32058133 DOI: 10.1016/j.chemosphere.2020.126125

The application of chemical dispersants in marine oil spill remediation is comprehensively reported across the globe. But, the augmented toxicity and poor biodegradability of reported chemical dispersants have created necessity for their replacement with the bio-based green dispersants. Therefore, in the present study, we have synthesized five ionic liquids (ILs) namely 1-butyl-3-methylimidazolium lauroylsarcosinate, 1,1'-(1,4-butanediyl)bis(1-H-pyrrolidinium) dodecylbenzenesulfonate, tetrabutylammonium citrate, tetrabutylammonium polyphosphate and tetrabutylammonium ethoxylate oleyl ether glycolate, and formulated a water based ILs dispersant combining the synthesized ILs at specified compositions. The effectiveness of formulated ILs dispersant was found between 70.75% and 94.71% for the dispersion of various crude oils ranging from light to heavy. Further, the acute toxicity tests against zebra fish and grouper fish have revealed the practically non-toxic behaviour of formulated ILs dispersant with LC50 value greater than 100 ppm after 96 h. In addition, the formulated ILs dispersant has provided excellent biodegradability throughout the test period. Overall, the formulated new ILs dispersant is deemed to facilitate environmentally benign oil spill remediation and could effectively substitute the use of hazardous chemical dispersants in immediate future.

Matched MeSH terms: Hazardous Substances
Fulltext Application of the cellular oxidation biosensor to Toxicity Identification Evaluations for high-throughput toxicity assessment of river water

Ooi L, Okazaki K, Arias-Barreiro CR, Heng LY, Mori IC

Chemosphere, 2020 May;247:125933.
PMID: 32079055 DOI: 10.1016/j.chemosphere.2020.125933

Toxicity Identification Evaluation (TIE) is a useful method for the classification and identification of toxicants in a composite environment water sample. However, its extension to a larger sample size has been restrained owing to the limited throughput of toxicity bioassays. Here we reported the development of a high-throughput method of TIE Phase I. This newly developed method was assisted by the fluorescence-based cellular oxidation (CO) biosensor fabricated with roGFP2-expressing bacterial cells in 96-well microplate format. The assessment of four river water samples from Langat river basin by this new method demonstrated that the contaminant composition of the four samples can be classified into two distinct groups. The entire toxicity assay consisted of 2338 tests was completed within 12 h with a fluorescence microplate reader. Concurrently, the sample volume for each assay was reduced to 50 μL, which is 600 to 4700 times lesser to compare with conventional bioassays. These imply that the throughput of the CO biosensor-assisted TIE Phase I is now feasible for constructing a large-scale toxicity monitoring system, which would cover a whole watershed scale.

Matched MeSH terms: Hazardous Substances
Improving safety-related knowledge, attitude and practices of nurses handling cytotoxic anticancer drug: pharmacists' experience in a general hospital, Malaysia

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*
Occurrence, distribution, and dechlorination of polychlorinated biphenyls and health risk assessment in Selangor River basin

Sakai N, Dayana E, Abu Bakar A, Yoneda M, Nik Sulaiman NM, Ali Mohd M

Environ Monit Assess, 2016 Oct;188(10):592.
PMID: 27679511

Polychlorinated biphenyls (PCBs) were monitored in surface water collected in the Selangor River basin, Malaysia, to identify the occurrence, distribution, and dechlorination process as well as to assess the potential adverse effects to the Malaysian population. Ten PCB homologs (i.e., mono-CBs to deca-CBs) were quantitated by using gas chromatography-mass spectrometry (GC/MS). The total concentration of PCBs in the 10 sampling sites ranged from limit of detection to 7.67 ng L(-1). The higher chlorinated biphenyls (tetra-CBs to deca-CBs) were almost not detected in most of the sampling sites, whereas lower chlorinated biphenyls (mono-CBs, di-CBs, and tri-CBs) dominated more than 90 % of the 10 homologs in all the sampling sites. Therefore, the PCB load was estimated to be negligible during the sampling period because PCBs have an extremely long half-life. The PCBs, particularly higher chlorinated biphenyls, could be thoroughly dechlorinated to mono-CBs to tri-CBs by microbial decomposition in sediment or could still be accumulated in the sediment. The lower chlorinated biphenyls, however, could be resuspended or desorbed from the sediment because they have faster desorption rates and higher solubility, compared to the higher chlorinated biphenyls. The health risk for the Malaysia population by PCB intake that was estimated from the local fish consumption (7.2 ng kg(-1) bw day(-1)) and tap water consumption (1.5 × 10(-3)-3.1 × 10(-3) ng kg(-1) bw day(-1)) based on the detected PCB levels in the surface water was considered to be minimal. The hazard quotient based on the tolerable daily intake (20 ng kg(-1) bw day(-1)) was estimated at 0.36.

Matched MeSH terms: Hazardous Substances/analysis
Analysis of the comprehensibility of chemical hazard communication tools at the industrial workplace

Ta GC, Mokhtar MB, Mohd Mokhtar HA, Ismail AB, Abu Yazid MF

Ind Health, 2010;48(6):835-44.
PMID: 20616463

Chemical classification and labelling systems may be roughly similar from one country to another but there are significant differences too. In order to harmonize various chemical classification systems and ultimately provide consistent chemical hazard communication tools worldwide, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) was endorsed by the United Nations Economic and Social Council (ECOSOC). Several countries, including Japan, Taiwan, Korea and Malaysia, are now in the process of implementing GHS. It is essential to ascertain the comprehensibility of chemical hazard communication tools that are described in the GHS documents, namely the chemical labels and Safety Data Sheets (SDS). Comprehensibility Testing (CT) was carried out with a mixed group of industrial workers in Malaysia (n=150) and factors that influence the comprehensibility were analysed using one-way ANOVA. The ability of the respondents to retrieve information from the SDS was also tested in this study. The findings show that almost all the GHS pictograms meet the ISO comprehension criteria and it is concluded that the underlying core elements that enhance comprehension of GHS pictograms and which are also essential in developing competent persons in the use of SDS are training and education.

Matched MeSH terms: Hazardous Substances/adverse effects; Hazardous Substances/toxicity*
Model for the implementation of the globally harmonized system of classification and labelling of chemicals (GHS): lessons learned from Japan

Ta GC, Jonai H, Mokhtar MB, Peterson PJ

J Occup Health, 2009;51(6):526-30.
PMID: 19834280
Matched MeSH terms: Hazardous Substances/classification*
Fulltext Occupational and Environmental Risk Factors Influencing the Inducement of Erythema among Nigerian Laboratory University Workers with Multiple Chemical Exposures

Reuben U, Ismail AF, Ahmad AL, Maina HM, Daud A

Int J Environ Res Public Health, 2019 04 13;16(8).
PMID: 31013942 DOI: 10.3390/ijerph16081334

: The chemicals from laboratories pose a significant risk forinducing erythema, an abnormal redness of the skin, as a result of poor occupational and environmental factors that promote hypersensitivity to a chemical agent. The aim of this present study was to determine the occupational and environmental risk factors influencing the inducement of erythema in laboratory workers due to exposure to chemicals. This was a cross-sectional study on a population-based sample of Nigerian university laboratory workers. Data were collected using the erythema index meter and an indoor air control meter. The study included 287 laboratory workers. The laboratory workers who properly used personal protective equipment (PPE) were 60% less likely to have induced erythema (adjusted odds ratio (AOR) = 0.40; 95% confidence interval CI: 0.22-0.77; probability value p = 0.011). The chemical mixture exceeding the permissible exposure limit (PEL) was found to have a small effect in inducing the erythema (AOR = 4.22; 95%CI: 2.88-12.11; p = 0.004). Most of the sampled laboratories where the respondents worked had unsuitable temperatures (AOR = 8.21; 95% CI: 4.03-15.01; p = 0.001). Erythema was more frequently found in the respondents who spent 4-5h in the laboratory (AOR = 3.11; 95%CI: 1.77-9.23; p = 0.001). However, high levels of ventilation reduce the likelihood of erythema in a laboratory by 82% (0.18). Multiple logistic regressions revealed that PPE, PEL, exposure time, temperature, and ventilation were the probable predictive factors associated with the inducement of erythema. Providing better educational knowledge and improving the attitude towards hazards and safety in a laboratory would lead to reduced rates of new cases.

Matched MeSH terms: Hazardous Substances/toxicity*
Effective hospital waste classification to overcome occupational health issues and reduce waste disposal cost

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
A novel nanobiosensor for the detection of paraoxon using chitosan-embedded organophosphorus hydrolase immobilized on Au nanoparticles

Karami R, Mohsenifar A, Mesbah Namini SM, Kamelipour N, Rahmani-Cherati T, Roodbar Shojaei T, et al.

Prep Biochem Biotechnol, 2015 Oct 26.
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
Fulltext Empowering occupational health doctors through the occupational safety & health (noise exposure) regulations 2019

Manivasagam, Dayanath

Journal of Occupational Safety and Health, 2019;16(1):1-7.
MyJurnal

The Department of Occupational Safety and Health Malaysia (DOSH) is the authority responsible to safeguard the occupational safety, health and welfare of workers in Malaysia. Occupational noise-related hearing disorders are the leading type of occupational diseases recorded by DOSH every year. Occupational Health Doctor (OHD) is a competency recognized by DOSH and their scope of duties in industries is currently confined to conduct medical surveillance for workers with hazardous chemical exposure and confined space medical fitness examination. The duties of OHD are good to be expanded by empowering more of their roles in industrial activities involving other legislations under DOSH. The noise exposure regulation under the Factories and Machinery Act (FMA) 1967 has been governing the worker’s exposure to hazardous industrial noise and preventing noise-induced hearing loss (NIHL) since 1989. However, the provisions of the regulation need to be strengthened in some essential medical elements of the Hearing Conservation Programme (HCP) for a comprehensive prevention of NIHL at the workplace. Recently enacted Occupational Safety and Health (Noise Exposure) Regulations 2019 offer a wider coverage of workers in ten sectors of industries applicable under the Occupational Safety and Health Act (OSHA) 1994. The current regulatory requirements for management of workplace noise have many improvements compared to the existing law. Enhancement in the medical requirements of industrial audiometry is made prominent by involving OHDs to interpret audiograms and conduct medical examination for workers. The reporting of occupational noise-related hearing disorders to DOSH is outlined better in the new regulation. The occurrence of NIHL and other related hearing disorders are expected to reduce eventually after the introduction of Occupational Safety and Health (Noise Exposure) Regulations 2019. The OHDs will play a pivotal role in industrial audiometry and prevention of hearing disorders among the working population.

Matched MeSH terms: Hazardous Substances
Current status of food safety hazards and health risks connected with aquatic food products from Southeast Asian region

Gao P, Mohd Noor NQI, Md Shaarani S

Crit Rev Food Sci Nutr, 2020 Dec 28.
PMID: 33356490 DOI: 10.1080/10408398.2020.1866490

Food safety issues associated with aquatic food products become more important with the increasing consumption and followed by its ongoing challenges. The objective of this paper is to review the food safety hazards and health risks related to aquatic food products for the Southeast Asian region. These hazards can be categorized as microplastics (MPs) hazard, biological hazards (pathogenic bacteria, biogenic amines, viruses, parasites), and chemical hazards (antimicrobial, formaldehyde, heavy metal). In different Southeast Asian countries, the potential health risks of aquatic food products brought by food hazards to consumers were at different intensity and classes. Among all these hazards, pathogenic bacteria, antimicrobials, and heavy metal were a particular concern in the Southeast Asian region. With environmental changes, evolving consumption patterns, and the globalization of trade, new food safety challenges are created, which put forward higher requirements on food technologies, food safety regulations, and international cooperation.

Matched MeSH terms: Hazardous Substances
Fulltext Pythium Damping-Off and Root Rot of Capsicum annuum L.: Impacts, Diagnosis, and Management

Arora H, Sharma A, Sharma S, Haron FF, Gafur A, Sayyed RZ, et al.

Microorganisms, 2021 Apr 13;9(4).
PMID: 33924471 DOI: 10.3390/microorganisms9040823

Capsicum annuum L. is a significant horticulture crop known for its pungent varieties and used as a spice. The pungent character in the plant, known as capsaicinoid, has been discovered to have various health benefits. However, its production has been affected due to various exogenous stresses, including diseases caused by a soil-borne pathogen, Pythium spp. predominantly affecting the Capsicum plant in younger stages and causing damping-off, this pathogen can incite root rot in later plant growth stages. Due to the involvement of multiple Pythium spp. and their capability to disperse through various routes, their detection and diagnosis have become crucial. However, the quest for a point-of-care technology is still far from over. The use of an integrated approach with cultural and biological techniques for the management of Pythium spp. can be the best and most sustainable alternative to the traditionally used and hazardous chemical approach. The lack of race-specific resistance genes against Pythium spp. can be compensated with the candidate quantitative trait loci (QTL) genes in C. annuum L. This review will focus on the epidemiological factors playing a major role in disease spread, the currently available diagnostics in species identification, and the management strategies with a special emphasis on Pythium spp. causing damping-off and root rot in different cultivars of C. annuum L.

Matched MeSH terms: Hazardous Substances
Fulltext Niigata Minamata disease: a revisit

Hasni MJ

Malaysian Journal of Public Health Medicine, 2014;14(1):47-54.
MyJurnal

Minamata disease is a well-known mercury contamination that happened in Japan in 1953. Due to demand during world war, second mercury disaster occurred in Niigata Prefecture in 1965. This is a review on the Niigata Minamata disease based on available documents and local expert opinions on the disaster. The aims of this paper are to record exposure history like the source of mercury in Agano River and specific fish that was associated with the disease. It is for an appraisal of the basic mercury exposure control, particularly to protect Japanese and world population during that time. There was indication that initial exposure limit for mercury was calculated incorrectly, and higher safe dose was applied. This epidemiological study is very useful and significant in comprehend the correct estimation of the human exposure to any hazardous substances.

Matched MeSH terms: Hazardous Substances
Fulltext Comparison of direct method and indirect methods for sampling and analysis of airborne respirable crystaline silica by X-ray difractometer

Suhaily Amran, Ahmad Sayuti Zainal Abidin, Shoffian Amin Jaafar, Mohd Talib Latif, Abdul Mutalib Leman

Journal of Occupational Safety and Health, 2015;12(1):137-141.
MyJurnal

There are several alternative sampling and analytical methods available for the determination of respirable
crystalline silica exposure among workers. The commonly used ones are, (1) NIOSH Manual Analytical Method
No.7500(NMAM 7500) which is Silica, crystalline, by X-ray difractometer via filter deposition(NIOSH 2003), and
(2) MDHS 101 (Methods for the Determination of Hazardous Substances (MDHS) Guidance No.101: Respirable
crystalline silica in respirable airborne dust). The aim of this study is to compare applicability of respirable crystalline
silica sampling and analysis between method MDHS 101 and NMAM 7500. Laboratory procedures will be performed
strictly based on MDHS 101 and NMAM 7500. Both methods apply X-ray diffraction as analytical technique with
many variations on sampling techniques and laboratory preparations. Quality assurance values such as detection
limits, accuracy and precision are derived from both data and will be compared to determine which of the method
establishes better quality assurance. The method which establishes better quality assurance will be recommend to be
used in Malaysian respirable crystalline silica monitoring programme. The strength of this research lies on its potential
to provide local capabilities in analysis of respirable crystalline silica in Malaysian setting.

Matched MeSH terms: Hazardous Substances
Fulltext Protection of Reinforced Concrete Structures of Waste Water Treatment Reservoirs with Stainless Steel Coating Using Arc Thermal Spraying Technique in Acidified Water

Lee HS, Park JH, Singh JK, Ismail MA

Materials (Basel), 2016 Sep 03;9(9).
PMID: 28773875 DOI: 10.3390/ma9090753

Waste water treatment reservoirs are contaminated with many hazardous chemicals and acids. Reservoirs typically comprise concrete and reinforcement steel bars, and the main elements responsible for their deterioration are hazardous chemicals, acids, and ozone. Currently, a variety of techniques are being used to protect reservoirs from exposure to these elements. The most widely used techniques are stainless steel plating and polymeric coating. In this study, a technique known as arc thermal spraying was used. It is a more convenient and economical method for protecting both concrete and reinforcement steel bar from deterioration in waste water treatment reservoirs. In this study, 316L stainless steel coating was applied to a concrete surface, and different electrochemical experiments were performed to evaluate the performance of coatings in different acidic pH solutions. The coating generated from the arc thermal spraying process significantly protected the concrete surface from corrosion in acidic pH solutions, owing to the formation of a double layer capacitance-a mixture of Cr3+ enriched with Cr₂O₃ and Cr-hydroxide in inner and Fe3+ oxide on the outer layer of the coating. The formation of this passive film is defective owing to the non-homogeneous 316L stainless steel coating surface. In the pH 5 solution, the growth of a passive film is adequate due to the presence of un-dissociated water molecules in the aqueous sulfuric acid solution. The coated surface is sealed with alkyl epoxide, which acts as a barrier against the penetration of acidic solutions. This coating exhibits higher impedance values among the three studied acidic pH solutions.

Matched MeSH terms: Hazardous Substances
Polycyclic aromatic hydrocarbon removal from petroleum sludge cake using thermal treatment with additives

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*

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