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Radiological impacts of the amang processing industry on neighbouring residents

Ismail B, Redzuwan Y, Chua RS, Shafiee W

Appl Radiat Isot, 2001 Mar;54(3):393-7.
PMID: 11214872

The processing of amang (one of a number of tin-tailing products) for its valuable minerals has associated with the radiological and environmental problems. The processing and stockpiling of amang and ilmenite in open-air spaces, subject as it is to environmental influences, gives rise to a potential for affecting residents in adjacent area. A case study was carried out in a residential area neighbouring a typical amang plant to investigate the radiological impact to the residents. The average Effective Dose rates, calculated based on the contributions of Effective Dose rates from inhaled suspended radioactive dust, radon-thoron and their progeny, and external gamma radiation, were determined for selected houses. Results show that the occupants of those houses received Effective Dose rate, which cannot be differentiated from background. The major contributor to the average Effective Dose rate came from external radiation sources. Inhaled radon and its progeny was the second major contributor.
Runoff of the herbicides triclopyr and glufosinate ammonium from oil palm plantation soil

Tayeb MA, Ismail BS, Khairiatul-Mardiana J

Environ Monit Assess, 2017 Oct 11;189(11):551.
PMID: 29022154 DOI: 10.1007/s10661-017-6236-4

This study focused on the residue detection of the herbicides triclopyr and glufosinate ammonium in the runoff losses from the Tasik Chini oil palm plantation area and the Tasik Chini Lake under natural rainfall conditions in the Malaysian tropical environment. Triclopyr and glufosinate ammonium are post-emergence herbicides. Both herbicides were foliar-sprayed on 0.5 ha of oil palm plantation plots, which were individualized by an uneven slope of 10-15%. Samples were collected at 1, 3, 7, 15, 30, 45, 60, 90, and 120 days after treatment. The concentrations of both herbicides quickly diminished from those in the analyzed sample by the time of collection. The highest residue levels found in the field surface leachate were 0.031 (single dosage, triclopyr), 0.041 (single dosage, glufosinate ammonium), 0.017 (double dosage, triclopyr), and 0.037 μg/kg (double dosage, glufosinate ammonium). The chromatographic peaks were observed at "0" day treatment (2 h after herbicide application). From the applied active ingredients, the triclopyr and glufosinate losses were 0.025 and 0.055%, respectively. The experimental results showed that both herbicides are less potent than other herbicides in polluting water systems because of their short persistence and strong adsorption onto soil clay particles.
Evaluation of the Persistence and Leaching Behaviour of Thiram Fungicide in Soil, Water and Oil Palm Leaves

Maznah Z, Halimah M, Ismail BS

Bull Environ Contam Toxicol, 2018 May;100(5):677-682.
PMID: 29516138 DOI: 10.1007/s00128-018-2312-x

The residual levels and persistence of thiram in the soil, water and oil palm seedling leaves were investigated under field conditions. The experimental plots were carried out on a clay loam soil and applied with three treatments namely; manufacturer's recommended dosage (25.6 g a.i. plot-1), manufacturer's double recommended dosage (51.2 g a.i. plot-1), and control (water) were applied. Thiram residues were detected in the soil from day 0 to day 3 in the range of 0.22-27.04 mg kg-1. Low concentrations of thiram were observed in the water and leave samples in the range of 0.27-2.52 mg L-1 and 1.34-12.28 mg kg-1, respectively. Results have shown that thiram has a rapid degradation and has less persistence due to climatic factors. These findings suggest that thiram is safe when applied at manufacturer's recommended dosage on oil palm seedlings due to low residual levels observed in soil and water bodies.
Evaluation on persistence and mobility of metsulfuron-methyl at oil palm plantation: residue field trial experiment versus VARLEACH model

Maznah Z, Ismail BS, Ooi KE

Environ Sci Pollut Res Int, 2021 Oct 31.
PMID: 34718969 DOI: 10.1007/s11356-021-17172-4

The present paper discussed the comparison of the persistence and mobility of metsulfuron-methyl from a residue field trial experiment and simulation using a VARLEACH model. The residue field trial experiment was performed at Sungai Buloh Oil Palm Estate, Selangor. The plots were treated with metsulfuron-methyl at two treatment rates of 15 g a.i ha-1 (T1) and 30 g a.i ha-1 (T2). Soil samples were collected at 0, 1, 3, 7, 14, 21, 30, 60 and 90 days after treatment (DAT) and analysed subsequently by HPLC-UV. The results show that metsulfuron-methyl degraded rapidly in the soil with the half-life (t½) of 6.3 days in T1 and 7.9 days in T2. The simulation of VARLEACH model gave similar pattern of persistence and mobility of metsulfuron-methyl in the soil profile. However, total residues and the mobility of the metsulfuron-methyl were poorly simulated by the VARLEACH model due to consistent overestimation of the quantified residues. Results indicated that the metsulfuron-methyl lost more rapidly than the prediction values from VARLEACH model. In this case, simulation models which use transformation routines similar and which include additional degraded processes such as leaching, volatilisation, plant uptake or runoff could be considered. Albeit, overestimated values on the concentrations of metsulfuron-methyl are reported using VARLEACH model, the model still can be used as rapid and fast approach to predict the behaviour of pesticide at minimum cost.
Nucleotide variability in the 5-enolpyruvylshikimate-3-phosphate synthase gene from Eleusine indica (L.) Gaertn

Chong JL, Wickneswari R, Ismail BS, Salmijah S

Pak J Biol Sci, 2008 Feb 01;11(3):476-9.
PMID: 18817177

This study reports the results of the partial DNA sequence analysis of the 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant (R) and glyphosate-susceptible (S) biotypes of Eleusine indica (L.) Gaertn from Peninsular Malaysia. Sequencing results revealed point mutation at nucleotide position 875 in the R biotypes of Bidor, Chaah and Temerloh. In the Chaah R population, substitution of cytosine (C) to adenine (A) resulted in the change of threonine (Thr106) to proline (Pro106) and from C to thymidine (T) in the Bidor R population, leading to serine (Ser106) from Pro106. As for the Temerloh R, C was substituted by T resulting in the change of Pro106 to Ser106. A new mutation previously undetected in the Temerloh R was revealed with C being substituted with A, resulting in the change of Pro106 to Thr106 indicating multiple founding events rather than to the spread of a single resistant allele. There was no point mutation recorded at nucleotide position 875 previously demonstrated to play a pivotal role in conferring glyphosate resistance to E. indica for the Lenggeng, Kuala Selangor, Melaka R populations. Thus, there may be another resistance mechanism yet undiscovered in the resistant Lenggeng, Kuala Selangor and Melaka populations.
Pesticide risk assessment: A study on inhalation and dermal exposure to 2,4-D and paraquat among Malaysian paddy farmers

Baharuddin MR, Sahid IB, Noor MA, Sulaiman N, Othman F

J Environ Sci Health B, 2011;46(7):600-7.
PMID: 21749249 DOI: 10.1080/03601234.2011.589309

A cross-section analytical study was conducted to evaluate the risk of pesticide exposure to those applying the Class II pesticides 2,4-D and paraquat in the paddy-growing areas of Kerian, Perak, Malaysia. It investigated the influence of weather on exposure as well as documented health problems commonly related to pesticide exposure. Potential inhalation and dermal exposure for 140 paddy farmers (handlers of pesticides) were assessed. Results showed that while temperature and humidity affected exposure, windspeed had the strongest impact on pesticide exposure via inhalation. However, the degree of exposure to both herbicides via inhalation was below the permissible exposure limits set by United States National Institute of Occupational Safety and Health (NIOSH). Dermal Exposure Assessment Method (DREAM) readings showed that dermal exposure with manual spraying ranged from moderate to high. With motorized sprayers, however, the level of dermal exposure ranged from low to moderate. Dermal exposure was significantly negatively correlated with the usage of protective clothing. Various types of deleterious health effects were detected among users of manual knapsack sprayers. Long-term spraying activities were positively correlated with increasing levels of the gamma-glutamyl transpeptidase (GGT) liver enzyme. The type of spraying equipment, usage of proper protective clothing and adherence to correct spraying practices were found to be the most important factors influencing the degree of pesticide exposure among those applying pesticides.
Adsorption study of 14C-paraquat in two Malaysian agricultural soils

Muhamad H, Ismail BS, Sameni M, Mat N

Environ Monit Assess, 2011 May;176(1-4):43-50.
PMID: 20582739 DOI: 10.1007/s10661-010-1565-6

The adsorption equilibrium time and effects of pH and concentration of (14)C-labeled paraquat (1,1(')-dimethyl-4,4(')-bipyridylium dichloride) in two types of Malaysian soil were investigated. The soils used in the study were clay loam and clay soils from rice fields. Equilibrium studies of paraquat in a soil and pesticide solution were conducted. Adsorption equilibrium time was achieved within 2 h for both soil types. The amount of (14)C-labeled paraquat adsorbed onto glass surfaces increased with increasing shaking time and remained constant after 10 h. It was found that paraquat adsorbed by the two soils was very similar: 51.73 (clay loam) and 51.59 μ g g(-1) (clay) at 1 μ g/ml. The adsorption of paraquat onto both types of soil was higher at high pH, and adsorption decreased with decreasing pH. At pH 11, the amounts of (14)C-labeled paraquat adsorbed onto the clay loam and clay soil samples were 4.08 and 4.05 μ g g(-1), respectively, whereas at pH 2, the amounts adsorbed were 3.72 and 3.57 μ g g(-1), respectively. Results also suggested that paraquat sorption by soil is concentration dependent.
Study on organochlorine compounds in cockles, Anadara granosa and mussels, Perna viridis from aquaculture sites in peninsular Malaysia

Ang CW, Mazlin NM, Heng LY, Ismail BS, Salmijah S

Bull Environ Contam Toxicol, 2005 Jul;75(1):170-4.
PMID: 16228889
Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils

Halimah M, Ismail BS, Nashriyah M, Maznah Z

Bull Environ Contam Toxicol, 2016 Jan;96(1):120-4.
PMID: 26546229 DOI: 10.1007/s00128-015-1685-3

The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos.
Leaching potential of pesticides in a vegetable farm in the Cameron Highlands, Malaysia

Ismail BS, Ngan CK, Cheah UB, Abdullah WY

Bull Environ Contam Toxicol, 2004 Apr;72(4):836-43.
PMID: 15200001 DOI: 10.1007/s00128-004-0320-5
Fulltext Prevalence of menopausal symptoms, its effect to quality of life among Malaysian women and their treatment seeking behaviour

Abdullah B, Moize B, Ismail BA, Zamri M, Mohd Nasir NF

Med J Malaysia, 2017 04;72(2):94-99.
PMID: 28473671

INTRODUCTION: This study aimed to determine the prevalence of menopausal symptoms, its effect to the quality of life and their treatment seeking behaviour in a multiracial community in Malaysia.

METHODS: This is a cross-sectional study involving postmenopausal women in Klang Valley, Malaysia. Data was obtained by face-to-face interview using standardised questionnaires on sociodemographic data, Menopause Rating Scale questionnaire, effect to quality of life and treatment sought.

RESULTS: A total of 258 women, including Malays (82%), Indians (14.1%) and Chinese (3.9%) were recruited. The median age was 58 (range 45-86) years old. Joint and muscular discomfort (73.3%) and fatigue (59.3%) were the most prevalent symptoms. Significant association with ethnicity were demonstrated with Malays was found to have 3.1 times higher incidence of sexual problems than Indians, (Odds Ratio (OR) 3.103; 95%CI 1.209, 7.967) and Indian had 2.6 times higher incidence of irritability compared to Malays (OR 2.598; 95%CI 1.126, 5.992). Fifty-two percent of women felt that menopausal symptoms affected their quality of life but there were only 2.7% who were severely affected. There were 24.8% of women who sought treatment and only 20.3% of those who took hormone replacement therapy. There was no significant association found between their treatment seeking behaviour in association with ethnicity, age, parity, marital and occupational status.

CONCLUSION: Menopausal symptoms were prevalent among menopausal women, although only a small group of women who were severely affected. There was a lack of tendency in seeking treatment for menopausal symptoms among the women.
Movement and persistence of methamidophos in vegetable agroecosystem

Ismail BS, Cheah UB, Enoma AO, Lum KY, Malik Z

Bull Environ Contam Toxicol, 2002 Sep;69(3):444-51.
PMID: 12177768
Fulltext Predictors of polymyxin B treatment failure in Gram-negative healthcare-associated infections among critically ill patients

Ismail B, Shafei MN, Harun A, Ali S, Omar M, Deris ZZ

J Microbiol Immunol Infect, 2018 Dec;51(6):763-769.
PMID: 28716359 DOI: 10.1016/j.jmii.2017.03.007

BACKGROUND: With increasing prevalence and spread of multidrug resistant Gram-negative infections, parenteral polymyxins resurged in clinical practice. The primary aim of the study was to determine the predictors of treatment failure and in-hospital mortality among critically ill patients treated with polymyxin B.
METHODS: Demographic data, underlying diseases, procedures and details on polymyxin B therapy were retrospectively analyzed in a cohort of 84 patients who received intravenous polymyxin B in an intensive care unit from 2010 to 2014.
RESULTS: Polymyxin B was used to treat bacteremia (46.4% of cases) and pneumonia (53.6%). Majority of the pathogens isolated were Acinetobacter spp. (96.4%). The mortality rate was 48.8%, of which 82.9% was attributed to polymyxin B treatment failure. The independent predictors of treatment failure were low doses of polymyxin B (p = 0.002), shorter duration of therapy (p = 0.009), not combining with cefoperazone/sulbactam (p = 0.030), female gender (p = 0.004), administered for treatment of bacteremia (p = 0.023) and renal impairment (p = 0.021). Low polymyxin B doses (p = 0.007), not combining with cefoperazone/sulbactam (p = 0.024), female gender (p = 0.048) and renal impairment (p = 0.022) were also significant predictors for in-hospital mortality.
CONCLUSIONS: To the best of our knowledge, this is the first report on the association of inadequate dose of polymyxin B (<15,000 units/kg/day) with poor outcome in critically ill patients. Besides that, further clinical studies are warranted to evaluate the use of cefoperazone/sulbactam as second antibiotic in the combination therapy.