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Environmental surveillance of SARS-CoV-2 in municipal wastewater to monitor COVID-19 status in urban clusters in Malaysia

Aziz MA, Norman S, Mohamed Zaid S, Simarani K, Sulaiman R, Mohd Aris A, et al.

Arch Microbiol, 2023 Jan 28;205(2):76.
PMID: 36708390 DOI: 10.1007/s00203-023-03417-y

Wastewater monitoring for SARS-CoV-2 has attracted considerable attention worldwide to complement the existing clinical-based surveillance system. In this study, we report our first successful attempt to prove the circulation of SARS-CoV-2 genes in Malaysian urban wastewater. A total of 18 wastewater samples were obtained from a regional sewage treatment plant that received municipal sewage between February 2021 and May 2021. Using the quantitative PCR assay targeting the E and RdRp genes of SARS-CoV-2, we confirmed that both genes were detected in the raw sewage, while no viral RNA was found in the treated sewage. We were also able to show that the trend of COVID-19 cases in Kuala Lumpur and Selangor was related to the changes in SARS-CoV-2 RNA levels in the wastewater samples. Overall, our study highlights that monitoring wastewater for SARS-CoV-2 should help local health professionals to obtain additional information on the rapid and silent circulation of infectious agents in communities at the regional level.
A review of antibiotic removal from domestic wastewater using the activated sludge process: removal routes, kinetics and operational parameters

Chen CX, Aris A, Yong EL, Noor ZZ

Environ Sci Pollut Res Int, 2022 Jan;29(4):4787-4802.
PMID: 34775565 DOI: 10.1007/s11356-021-17365-x

Many advanced technologies have shown encouraging results in removing antibiotics from domestic wastewater. However, as activated sludge treatment is the most common sewage treatment system employed worldwide, improving its effect on antibiotic removal would be more desirable. Understanding the removal mechanisms, kinetics and factors that affect antibiotic removal in the activated sludge process is important as it would allow us to improve the treatment performance. Although these have been discussed in various literature covering different types of antibiotics and wastewater, a specific review on antibiotics and domestic wastewater is clearly missing. This review paper collates, discusses and analyses the removal of antibiotics from sewage in the activated sludge process along with the removal mechanisms and kinetics. The antibiotics are categorised into six classes: β-lactam, dihydrofolate reductase inhibitor, fluoroquinolone, macrolide, sulfonamides and tetracycline. Furthermore, the factors affecting the system performance with regard to antibiotic removal are examined.
Effects of music therapy on physiological outcomes for post-operative total knee arthroplasty (TKA) patients

Aris A, Sulaiman S, Che Hasan MK

Enferm Clin, 2021 04;31 Suppl 2:S10-S15.
PMID: 33849138 DOI: 10.1016/j.enfcli.2020.10.006

This study aimed to investigate the effects of music on physiological outcomes for post-operative TKA patients in the recovery unit. Fifty-six patients from Hospital Melaka were randomized equally into intervention (IG) and control groups (CG). IG received the usual care and listened to selected music for 60min, while the CG received only the usual care. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiration rate (RR) and oxygen saturation (SpO2) were measured on arrival and after 10, 20, 30, and 60min in the recovery unit. A significant difference between groups was observed in RR upon arrival (U=276.5, p=0.029) and after 10min (U=291, p=0.45). Meanwhile, there were significant differences in DBP (F=3.158, p=0.032), RR (χ2=15.956, p=0.003) and SpO2 (χ2=14.084, p=0.007) over time in the IG. Overall, listening to music immediately after TKA has an effect on DBP, RR, and SpO2.
Influence of static mixer on the development of aerobic granules for the treatment of low-medium strength domestic wastewater

We ACE, Aris A, Zain NAM, Muda K, Sulaiman S

Chemosphere, 2021 Jan;263:128209.
PMID: 33297168 DOI: 10.1016/j.chemosphere.2020.128209

The present work investigates the feasibility of aerobic granulation for the treatment of low-medium strength domestic wastewater for long-term operation and effects of a static mixer on the properties and removal performances of the aerobic granules formed. The static mixer was installed in a sequential batch reactor to provide higher hydrodynamic shear force in enhancing the formation of the aerobic granules. Aerobic granules were successfully formed in the domestic wastewater, and the granulation treatment system was sustained for a period of 356 days without granules disintegration. Subsequent to the installation, aerobic granules with a low SVI30 of 41.37 mL/gTSS, average diameter 1.11 mm, granular strength with integrity coefficient 10.4% and regular shape with minimum filamentous outgrowth were formed. Mineral concentrations such as Fe, Mg, Ca and Na as well as composition of protein and polysaccharide in tightly bound-extracellular polymeric substance of the aerobic granules were found to be higher under the effect of the static mixer. However, no significant improvement was observed on the TCOD, NH4+-N and TSS removal performance. Good TCOD and TSS removal performance of above 85% and 90%, respectively and moderate NH4+-N removal performance of about 60% were observed throughout the study. Higher simultaneous nitrification and denitrification (SND) efficiency of 56% was observed after the installation of the static mixer, as compared to 21% prior. Therefore, it may be concluded that the installation of the static mixer significantly improved the properties of aerobic granules formation and SND efficiency but not the TCOD, NH4+-N and TSS removal performance.
Biocontrol efficacy of Trichoderma asperellum-enriched coconut fibre against Fusarium wilts of cherry tomato

Hasan ZAE, Mohd Zainudin NAI, Aris A, Ibrahim MH, Yusof MT

J Appl Microbiol, 2020 Oct;129(4):991-1003.
PMID: 32324939 DOI: 10.1111/jam.14674

AIMS: Agro-based wastes were evaluated as a medium for mass micropropagule production and optimal efficacy of Trichoderma asperellum B1092 in controlling Fusarium oxysporum f. sp. lycopersici and promoting tomato growth. This study focused on biological control because pathogen persistence in the soil makes the disease difficult to control.
METHODS AND RESULTS: Rice bran, biochar, empty fruit bunches, coconut fibres, compost, top soil and mixed soil were evaluated as media for mass multiplication of T. asperellum, which is effective in controlling plant pathogens. Yielding the most colony forming units (CFU) among the media, coconut fibre was deemed most suitable for promoting sporulation. After 120 days on the medium, T. asperellum B1902 produced 9·053 × 105 CFU per gram coconut fibre; oil palm empty fruit bunches was second highest (7·406 × 105 CFU per gram). In field tests of T. asperellum B1092 against F. oxysporum f. sp lycopersici (causing Fusarium wilt of cherry tomato), B1092 significantly promoted plant growth compared to the control. The efficacy of this formulation resulted in increased growth of roots and shoots tomato plants and total lycopene, sugar, K, N, Ca, P and Mg content after 120 days.
CONCLUSIONS: Trichoderma asperellum B1092 showed great field potential for improving productivity and quality of tomatoes and in controlling Fusarium wilt of cherry tomato.
SIGNIFICANCE AND IMPACT OF THE STUDY: This innovative approach using a cheap agro-waste to control the persistent soil-borne Fusarium pathogen of cherry tomato should increase soil survival rate of Trichoderma and has potential for upscaling in the field for other crops.
Characterization of slowly-biodegradable organic compounds and hydrolysis kinetics in tropical wastewater for biological nitrogen removal

How SW, Sin JH, Wong SYY, Lim PB, Mohd Aris A, Ngoh GC, et al.

Water Sci Technol, 2020 Jan;81(1):71-80.
PMID: 32293590 DOI: 10.2166/wst.2020.077

Many developing countries, mostly situated in the tropical region, have incorporated a biological nitrogen removal process into their wastewater treatment plants (WWTPs). Existing wastewater characteristic data suggested that the soluble chemical oxygen demand (COD) in tropical wastewater is not sufficient for denitrification. Warm wastewater temperature (30 °C) in the tropical region may accelerate the hydrolysis of particulate settleable solids (PSS) to provide slowly-biodegradable COD (sbCOD) for denitrification. This study aimed to characterize the different fractions of COD in several sources of low COD-to-nitrogen (COD/N) tropical wastewater. We characterized the wastewater samples from six WWTPs in Malaysia for 22 months. We determined the fractions of COD in the wastewater by nitrate uptake rate experiments. The PSS hydrolysis kinetic coefficients were determined at tropical temperature using an oxygen uptake rate experiment. The wastewater samples were low in readily-biodegradable COD (rbCOD), which made up 3-40% of total COD (TCOD). Most of the biodegradable organics were in the form of sbCOD (15-60% of TCOD), which was sufficient for complete denitrification. The PSS hydrolysis rate was two times higher than that at 20 °C. The high PSS hydrolysis rate may provide sufficient sbCOD to achieve effective biological nitrogen removal at WWTPs in the tropical region.
Type 2 diabetes risk among university students in Malaysia

Aris A, Khalid MZM, Yahaya H, Yoong LO, Ying NQ

Curr Diabetes Rev, 2020;16(4):387-394.
PMID: 31433762 DOI: 10.2174/1573399815666190712192527

BACKGROUND: Type 2 diabetes (T2D) is a preventable condition. Targeting those who are at risk of getting this disease is essential.

OBJECTIVE: To examine T2D risk among university students in Malaysia and determine its relationship with socio-demographic characteristics and physical activity.

METHODS: The study was conducted cross-sectionally on 390 students selected using quota sampling method from 13 faculties in Universiti Kebangsaan Malaysia. A short form of the International Physical Activity Questionnaire and Finnish Diabetes Risk Score were used to measure the physical activity and T2D risk.

RESULTS: The T2D risk was found to be low (M = 5.23, SD = 3.32) with more than two-third of the student population at the low risk level while a significant proportion of 23.8%, 5.6% and 0.3% having slightly elevated, moderate and high risk respectively. The T2D risk was significantly related to their age (rho = 0.197, p < 0.000), gender (U = 12641, p = 0.011), ethnic group (Χ2 = 18.86, p < 0.000), marital status (Χ2 = 6.597, p = 0.037), residence (U = 10345, p = 0.008), academic year (Χ2 = 14.24, p = 0.007) and physical activity (rho = -0.205, p < 0.000 and Χ2 = 13.515, p = 0.001). Of these, only age (β=0.130) and physical activity (β=-0.159) remained significant in the regression analysis.

CONCLUSION: The findings call for a radical change in the nursing practice to target the amendable factors that are significant in order to prevent the progression of the risk towards type 2 diabetes.
Fulltext Live vaccines against bacterial fish diseases: A review

Mohd-Aris A, Muhamad-Sofie MHN, Zamri-Saad M, Daud HM, Ina-Salwany MY

Vet World, 2019 Nov;12(11):1806-1815.
PMID: 32009760 DOI: 10.14202/vetworld.2019.1806-1815

Fish diseases are often caused either by bacteria, viruses, fungi, parasites, or a combination of these pathogens. Of these, bacterial fish diseases are considered to be a major problem in the aquaculture industry. Hence, the prevention of such diseases by proper vaccination is one of the integral strategies in fish health management, aimed at reducing the fish mortality rate in the aquaculture farms. Vaccination offers an effective yet low-cost solution to combat the risk of disease in fish farming. An appropriate vaccination regime to prevent bacterial diseases offers a solution against the harmful effects of antibiotic applications. This review discusses the role of live-attenuated vaccine in controlling bacterial diseases and the development of such vaccines and their vaccination strategy. The current achievements and potential applications of live-attenuated and combined vaccines are also highlighted. Vaccine development is concluded to be a demanding process, as it must satisfy the requirements of the aquaculture industry.
The influence of music therapy on mental well-being among postoperative patients of total knee arthroplasty (TKA)

Aris A, Sulaiman S, Che Hasan MK

Enferm Clin, 2019 09;29 Suppl 2:16-23.
PMID: 31208927 DOI: 10.1016/j.enfcli.2019.04.004

OBJECTIVE: The objective of this study was to investigate whether music therapy affects immediate postoperative well-being among patients who had undergone TKA surgery in the recovery unit.
METHOD: A randomized controlled trial was conducted recruiting patients from Hospital Melaka, Malaysia. Postoperative TKA patients with good hearing and visual acuity, fully conscious and prescribed with patients controlled analgesia (PCA) were randomized to either intervention or control groups using a sealed envelope. Patients in the intervention group received usual care with additional music therapy during recovery, while patients in the control group received the usual care provided by the hospital. Two factors identified affecting mental well-being were the pain (measured using numerical rating scale) and anxiety (measured using a visual analog scale) at five different minutes' points (0, 10, 20, 30, and 60).
RESULTS: A total of 56 (control: 28, intervention: 28) postoperative TKA patients consented in the study. There was no difference in baseline characteristics between the two groups (p>0.05). Using Mann-Whitney U tests, patients in music therapy group showed significantly lower numerical pain score at 60min (p=0.045) whereas there was no significant difference between the two groups at all time points for anxiety scores (p>0.05). In the intervention group, Friedman tests showed that there was a significant difference in numerical pain (χ2=36.957, df=4, p<0.001) and anxiety score across times (χ2=18.545, p=0.001).
CONCLUSIONS: This study found that pain score decreases over time among patients in the music therapy group while no effect is seen for anxiety. It is suggested that music therapy could not affect postoperative TKA patients' mental well-being. Nonetheless, patients reported better pain score despite the small sample.
Lafora disease in a Malaysian with a rare mutation in the EPM2A gene

Tee SK, Ong TL, Aris A, See SML, Leong HY, Khalid MKNM, et al.

Seizure, 2019 Apr;67:78-81.
PMID: 30947044 DOI: 10.1016/j.seizure.2019.03.012
Bioavailability and mobility of arsenic, cadmium, and manganese in gold mine tailings amended with rice husk ash and Fe-coated rice husk ash

Tariq FS, Samsuri AW, Karam DS, Aris AZ, Jamilu G

Environ Monit Assess, 2019 Mar 21;191(4):232.
PMID: 30900076 DOI: 10.1007/s10661-019-7359-6

This study was conducted to determine the effects of rice husk ash (RHA) and Fe-coated rice husk ash (Fe-RHA) on the bioavailability and mobility of As, Cd, and Mn in mine tailings. The amendments were added to the tailings at 0, 5, 10, or 20% (w/w) and the mixtures were incubated for 0, 7, 15, 30, 45, and 60 days. The CaCl2 extractable As, Cd, and Mn in the amended tailings were determined at each interval of incubation period. In addition, the tailings mixture was leached with simulated rain water (SRW) every week from 0 day (D 0) until day 60 (D 60). The results showed that both RHA and Fe-RHA application significantly decreased the CaCl2-extractable Cd and Mn but increased that of As in the tailings throughout the incubation period. Consequently, addition of both RHA and Fe-RHA leached out higher amount of As from the tailings but decreased Cd and Mn concentration compared to the controls. The amount of As leached from the Fe-RHA-amended tailings was less than that from RHA-amended tailings. Application of both RHA and Fe-RHA could be an effective way in decreasing the availability of cationic heavy metals (Cd and Mn) in the tailings but these amendments could result in increasing the availability of anionic metalloid (As). Therefore, selection of organic amendments to remediate metal-contaminated tailings must be done with great care because the outcomes might be different among the elements.
Vibriosis in Fish: A Review on Disease Development and Prevention

Ina-Salwany MY, Al-Saari N, Mohamad A, Mursidi FA, Mohd-Aris A, Amal MNA, et al.

J Aquat Anim Health, 2019 03;31(1):3-22.
PMID: 30246889 DOI: 10.1002/aah.10045

Current growth in aquaculture production is parallel with the increasing number of disease outbreaks, which negatively affect the production, profitability, and sustainability of the global aquaculture industry. Vibriosis is among the most common diseases leading to massive mortality of cultured shrimp, fish, and shellfish in Asia. High incidence of vibriosis can occur in hatchery and grow-out facilities, but juveniles are more susceptible to the disease. Various factors, particularly the source of fish, environmental factors (including water quality and farm management), and the virulence factors of Vibrio, influence the occurrence of the disease. Affected fish show weariness, with necrosis of skin and appendages, leading to body malformation, slow growth, internal organ liquefaction, blindness, muscle opacity, and mortality. A combination of control measures, particularly a disease-free source of fish, biosecurity of the farm, improved water quality, and other preventive measures (e.g., vaccination) might be able to control the infection. Although some control measures are expensive and less practical, vaccination is effective, relatively cheap, and easily implemented. In this review, the latest knowledge on the pathogenesis and control of vibriosis, including vaccination, is discussed.
Mass transfer kinetics of biosorption of nitrogenous matter from palm oil mill effluent by aerobic granules in sequencing batch reactor

Fulazzaky MA, Nuid M, Aris A, Muda K

Environ Technol, 2018 Sep;39(17):2151-2161.
PMID: 28675960 DOI: 10.1080/09593330.2017.1351494

Understanding of mass transfer kinetics is important for biosorption of nitrogen compounds from palm oil mill effluent (POME) to gain a mechanistic insight into future biological processes for the treatment of high organic loading wastewater. In this study, the rates of global and sequential mass transfer were determined using the modified mass transfer factor equations for the experiments to remove nitrogen by aerobic granular sludge accumulation in a sequencing batch reactor (SBR). The maximum efficiencies as high as 97% for the experiment run at [kLa]g value of 1421.8 h-1 and 96% for the experiment run at [kLa]g value of 9.6 × 1037 h-1 were verified before and after the addition of Serratia marcescens SA30, respectively. The resistance of mass transfer could be dependent on external mass transfer that controls the transport of nitrogen molecule along the experimental period of 256 days. The increase in [kLa]g value leading to increased performance of the SBR was verified to contribute to the future applications of the SBR because this phenomenon provides new insight into the dynamic response of biological processes to treat POME.
Low-dissolved-oxygen nitrification in tropical sewage: an investigation on potential, performance and functional microbial community

How SW, Lim SY, Lim PB, Aris AM, Ngoh GC, Curtis TP, et al.

Water Sci Technol, 2018 May;77(9-10):2274-2283.
PMID: 29757179 DOI: 10.2166/wst.2018.143

Intensive aeration for nitrification is a major energy consumer in sewage treatment plants (STPs). Low-dissolved-oxygen (low-DO) nitrification has the potential to lower the aeration demand. However, the applicability of low-DO nitrification in the tropical climate is not well-understood. In this study, the potential of low-DO nitrification in tropical setting was first examined using batch kinetic experiments. Subsequently, the performance of low-DO nitrification was investigated in a laboratory-scale sequential batch reactor (SBR) for 42 days using real tropical sewage. The batch kinetic experiments showed that the seed sludge has a relatively high oxygen affinity. Thus, the rate of nitrification was not significantly reduced at low DO concentrations (0.5 mg/L). During the operation of the low-DO nitrification SBR, 90% of NH4-N was removed. The active low-DO nitrification was mainly attributed to the limited biodegradable organics in the sewage. Fluorescence in-situ hybridisation and 16S rRNA amplicon sequencing revealed the nitrifiers were related to Nitrospira genus and Nitrosomonadaceae family. Phylogenetic analysis suggests 47% of the operational taxonomic units in Nitrospira genus are closely related to a comammox bacteria. This study has demonstrated active low-DO nitrification in tropical setting, which is a more sustainable process that could significantly reduce the energy footprint of STPs.
Status, source identification, and health risks of potentially toxic element concentrations in road dust in a medium-sized city in a developing country

Praveena SM, Aris AZ

Environ Geochem Health, 2018 Apr;40(2):749-762.
PMID: 28929262 DOI: 10.1007/s10653-017-0021-8

This study aims to determine the status of potentially toxic element concentrations of road dust in a medium-sized city (Rawang, Malaysia). This study adopts source identification via enrichment factor, Pearson correlation analysis, and Fourier spectral analysis to identify sources of potentially toxic element concentrations in road dust in Rawang City, Malaysia. Health risk assessment was conducted to determine potential health risks (carcinogenic and non-carcinogenic risks) among adults and children via multiple pathways (i.e., ingestion, dermal contact, and inhalation). Mean of potentially toxic element concentrations were found in the order of Pb > Zn > Cr(IV) > Cu > Ni > Cd > As > Co. Source identification revealed that Cu, Cd, Pb, Zn, Ni, and Cr(IV) are associated with anthropogenic sources in industrial and highly populated areas in northern and southern Rawang, cement factories in southern Rawang, as well as the rapid development and population growth in northwestern Rawang, which have resulted in high traffic congestion. Cobalt, Fe, and As are related to geological background and lithologies in Rawang. Pathway orders for both carcinogenic and non-carcinogenic risks are ingestion, dermal contact, and inhalation, involving adults and children. Non-carcinogenic health risks in adults were attributed to Cr(IV), Pb, and Cd, whereas Cu, Cd, Cr(IV), Pb, and Zn were found to have non-carcinogenic health risks for children. Cd, Cr(IV), Pb, and As may induce carcinogenic risks in adults and children, and the total lifetime cancer risk values exceeded incremental lifetime.
Waste bones ash as an alternative source of P for struvite precipitation

Darwish M, Aris A, Puteh MH, Jusoh MNH, Abdul Kadir A

J Environ Manage, 2017 Dec 01;203(Pt 2):861-866.
PMID: 26935149 DOI: 10.1016/j.jenvman.2016.02.033

Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4-N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed to find alternative sources of P, in order to maintain a sustainable NH4-N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4-N removal and high purity struvite.
A simple, selective, and sensitive gas chromatography-mass spectrometry method for the analysis of five process-related impurities in atenolol bulk drug and capsule formulations

Reddy AVB, Yusop Z, Jaafar J, Bin Aris A, Abdul Majid Z

J Sep Sci, 2017 Aug;40(15):3086-3093.
PMID: 28581679 DOI: 10.1002/jssc.201700252

An extremely sensitive and simple gas chromatography with mass spectrometry method was developed and completely validated for the analysis of five process-related impurities, viz., 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, 4-hydroxyphenylacetic acid, methyl-4-hydroxyphenylacetate, and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile, in atenolol. The separation of impurities was accomplished on a BPX-5 column with dimensions of 50 m × 0.25 mm i.d. and 0.25 μm film thickness. The method validation was performed following International Conference on Harmonisation guidelines in which the method was capable to quantitate 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenylacetic acid at 0.3 ppm, and methyl-4-hydroxyphenylacetate and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile at 0.35 ppm with respect to 10 mg/mL of atenolol. The method was linear over the concentration range of 0.3-10 ppm for 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenylacetic acid, and 0.35-10 ppm for methyl-4-hydroxyphenylacetate and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile. The correlation coefficient in each case was found ≥0.998. The repeatability and recovery values were acceptable, and found between 89.38% and 105.60% for all five impurities under optimized operating conditions. The method developed here is simple, selective, and sensitive with apparently better resolution than the reported methods. Hence, the method is a straightforward and good quality control tool for the quantitation of selected impurities at trace concentrations in atenolol.
Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry

Vijaya Bhaskar Reddy A, Yusop Z, Jaafar J, Bin Aris A, Abdul Majid Z, Umar K, et al.

J Sep Sci, 2016 Jun;39(12):2276-83.
PMID: 27095506 DOI: 10.1002/jssc.201600155

A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid-phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C18 cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected-ion monitoring mode. Good linear relationships were obtained in the range of 0.1-50 μg/L for chlorpyrifos, and 0.05-50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54-86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level.
Quality of Kelantan drinking water and knowledge, attitude and practice among the population of Pasir Mas, Malaysia

Ab Razak NH, Praveena SM, Aris AZ, Hashim Z

Public Health, 2016 Feb;131:103-11.
PMID: 26715317 DOI: 10.1016/j.puhe.2015.11.006

Information about the quality of drinking water, together with analysis of knowledge, attitude and practice (KAP) analysis and health risk assessment (HRA) remain limited. The aims of this study were: (1) to ascertain the level of KAP regarding heavy metal contamination of drinking water in Pasir Mas; (2) to determine the concentration of heavy metals (Al, Cr, Cu, Fe, Ni, Pb, Zn and Cd) in drinking water in Pasir Mas; and (3) to estimate the health risks (non-carcinogenic and carcinogenic) caused by heavy metal exposure through drinking water using hazard quotient and lifetime cancer risk.
Health Risk Assessment using in vitro digestion model in assessing bioavailability of heavy metal in rice: A preliminary study

Omar NA, Praveena SM, Aris AZ, Hashim Z

Food Chem, 2015 Dec 1;188:46-50.
PMID: 26041162 DOI: 10.1016/j.foodchem.2015.04.087

Little is known about the bioavailability of heavy metal contamination and its health risks after rice ingestion. This study aimed to determine bioavailability of heavy metal (As, Cd, Cu, Cr, Co, Al, Fe, Zn and Pb) concentrations in cooked rice and human Health Risk Assessment (HRA). The results found Zn was the highest (4.3±0.1 mg/kg), whereas As showed the lowest (0.015±0.001 mg/kg) bioavailability of heavy metal concentration in 22 varieties of cooked rice. For single heavy metal exposure, no potential of non carcinogenic health risks was found, while carcinogenic health risks were found only for As. Combined heavy metal exposures found that total Hazard Quotient (HQtotal) values for adult were higher than the acceptable range (HQTotal<1), whereas total Lifetime Cancer Risk (LCRTotal) values were higher than the acceptable range (LCRTotal values >1×10(-4)) for both adult and children. This study is done to understand that the inclusion of bioavailability heavy metal into HRA produces a more realistic estimation of human heavy metal exposure.

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