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The establishment of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is one of the global initiatives to promote effective chemical hazard communication worldwide. ...

This investigation quantified spatial variability of heavy metals and followed methods of the U.S. Environmental Protection Agency (EPA) to estimate the hazard indices as well as cancer risks associated with consuming fish caught in the waters of the Langat river basin area, Malaysia. The calculation of metal pollution index (MPI) was carried out to classify the study area according to the level of contamination and the order of stations from highest to lowest MPI values was Langat river > Cempaka lake > Engineering pond > Pond B > Pond A > Jugra > Bandar. The level of exposure due to the consumption of each chemical in Tilapia fish tissue was estimated in an average daily dose equation. The calculated HI ranging from 0.24 to 1.88 indicated 71% stations were in the risk level. Potential carcinogenic risks associated with the ingestion of heavy metals in Tilapia fish were evaluated probabilistically by performing 10,000 trials for Monte Carlo simulation. Cancer risk calculations exceeding the U.S. EPA’s acceptable risk level of 1 in 1,000,000 (or 10-6) included Ni (7.3×10-4) and Cd (2.1×10-6). However, the average carcinogenic risk (2.4×10-4) exceeded the accepted risk level to a great extent. The recommended daily ingestion rate of Tilapia for Malaysian people inhabiting Langat river basin area was calculated considering 95th percentile TR value of 10-6 as an acceptable risk where it is revealed that consumption of Tilapia should be reduced about 67% from the current level to have an acceptable risk of cancer.

Abundant of preparatory works have recognized that fluorescent sensors based on 8-aminoquinoline are popular tools to detect Zn2+ ions in environmental and biological applications. Along with these studies, researchers started to introduce a variety of carboxamido group into an 8-aminoquinoline molecule in forming 8-amidoquinoline derivatives. Therefore, this systematic review aims to introduce a general overview of the fluorophore 8-aminoquinoline as Zn2+ receptors and to provide comparisons of collected studies that related to 8-amidoquinoline derivatives as fluorophore probe of the sensor. According to PRISMA systematic searches strategy, 13 articles were analyzed for trends, research designs, results and discussion, subject samples, and remarks or conclusions. We found cross-sectional studies with four aspects in zinc sensing that have been targeted; binding studies via titration, detection's limit, interferences studies, and validation of the study. Hence, this paper also included assessments of those criteria and the trends of development of 8-amidoquinoline derivatives based-zinc fluorescent chemosensor. It also showed that most of the researches conducted in China. In conclusion, this study identified various research designs of fluorescent chemosensors based on 8-amidoquinoline prolong with the effectiveness and potential as a recognition probe to assist the detection of zinc. Hence, elucidation of those derivatives essential to be explored because more studies are needed to improve the sensing criteria of the zinc sensor

Prolonged persistence of toxic cadmium (Cd), chromium (Cr) and lead (Pb) in the aquatic environment are due to its nonbiodegradable characteristic. A few studies have reported higher concentrations of these metals in the transboundary Langat River, Malaysia. This study determined the spatial and temporal distributions of Cd, Cr and Pb concentrations (2005&ndash, 2015) in the Langat River along with assessing the status of these metals in the drinking water supply chain at the basin. Water samples were collected once in 2015 from the drinking water supply chain, i.e., from the river, treated water at plants, taps and filtration water at households. Determined mean concentrations of Cd, Cr and Pb by inductively coupled plasma mass spectrometry in the Langat River were within the drinking water quality standard of Malaysia and the WHO, except for the Pb (9.99 &plusmn, 1.40 &micro, g/L) concentration, which was at the maximum limit, 10 &micro, g/L. The spatial and temporal distribution of these metals&rsquo, concentrations indicate dilution of it downstream, along with the increasing trend in rainfall and water flow, especially during the northeast monsoon. Significant correlation and regression analysis of the Cd, Cr and Pb concentrations also indicate that the sources of this metal pollution are mainly the natural weathering of minerals along with anthropogenic activities in the basin. The determined overall water quality of the Langat River is categorized Class IIA (i.e., clean), which requires conventional treatment before drinking, however, the maximum removal efficiency of these metals by the plants at the basin was about 90.17%. Therefore, the proactive leadership roles of the local authorities will be appropriate to reduce the pollution of this river as well as introducing a two-layer water filtration system at the Langat River Basin to accelerate the achievement of a sustainable drinking water supply.

A DNA micro-optode for dengue virus detection was developed based on the sandwich hybridization strategy of DNAs on succinimide-functionalized poly(n-butyl acrylate) (poly(nBA-NAS)) microspheres. Gold nanoparticles (AuNPs) with an average diameter of ~20 nm were synthesized using a centrifugation-based method and adsorbed on the submicrometer-sized polyelectrolyte-coated poly(styrene-co-acrylic acid) (PSA) latex particles via an electrostatic method. The AuNP&ndash, latex spheres were attached to the thiolated reporter probe (rDNA) by Au&ndash, thiol binding to functionalize as an optical gold&ndash, latex&ndash, rDNA label. The one-step sandwich hybridization recognition involved a pair of a DNA probe, i.e., capture probe (pDNA), and AuNP&ndash, PSA reporter label that flanked the target DNA (complementary DNA (cDNA)). The concentration of dengue virus cDNA was optically transduced by immobilized AuNP&ndash, PSA&ndash, rDNA conjugates as the DNA micro-optode exhibited a violet hue upon the DNA sandwich hybridization reaction, which could be monitored by a fiber-optic reflectance spectrophotometer at 637 nm. The optical genosensor showed a linear reflectance response over a wide cDNA concentration range from 1.0 &times, 10&minus, 21 M to 1.0 &times, 12 M cDNA (R2 = 0.9807) with a limit of detection (LOD) of 1 &times, 29 M. The DNA biosensor was reusable for three consecutive applications after regeneration with mild sodium hydroxide. The sandwich-type optical biosensor was well validated with a molecular reverse transcription polymerase chain reaction (RT-PCR) technique for screening of dengue virus in clinical samples, e.g., serum, urine, and saliva from dengue virus-infected patients under informed consent.

Biosensor optik berasaskan hemoglobin (Hb) terpegun pada mikrosfera poli(n-butil akrilat-co-N-akriloksisuksinimida) [poli(nBA-NAS)] telah dibangunkan bagi mengesan kepekatan ion nitrit (NO2-). Kompleks HEM ferum dalam Hb memangkinkan tindak balas penurunan ion NO2- kepada nitrik oksida (NO) lalu bergabung dengan deoksihemoglobin (HbFe2+) membentuk kompleks ferum-nitrosil-hemoglobin (HbFe2+-NO) yang berwarna hijau kekuningan. Spektrofotometer pantulan gentian optik digunakan untuk memantau kepekatan ion NO2- secara kuantitatif berdasarkan perubahan warna Hb terpegun pada mikrosfera poliakrilat daripada perang kemerahan ke hijau kekuningan pada panjang gelombang pantulan maksimum 668 nm. Pencirian terhadap biosensor nitrit reflektometrik melibatkan ujian kesan pH, kesan kepekatan Hb, julat rangsangan linear, kebolehasilan, jangka hayat dan kesan gangguan ion telah dijalankan. Biosensor ion NO2- optik terbangun memaparkan julat linear dinamik daripada 5 hingga 50 mg mL-1 (R2=0.9894) pada pH7.0 dengan had pengesanan (LOD) sebanyak 3.3 mg mL-1 dan nilai sisihan piawai relatif (RSD) kebolehasilan biosensor sebanyak 5.8%. Jangka hayat biosensor optik nitrit tersebut adalah selama 36 hari dan majoriti ion asing yang sering wujud bersama ion NO2- dalam sampel air semula jadi tidak menunjukkan kesan gangguan yang bererti terhadap penentuan ion NO2- menggunakan biosensor optik terbangun kecuali ion Hg2+, Ag+, Br- dan S2-.

Benzene, toluene, ethylbenzene and xylenes (BTEX) are well known hazardous volatile organic compounds (VOCs) due to their human health risks and photochemical effects. The main objective of this study was to estimate BTEX levels and evaluate interspecies ratios and ozone formation potentials (OFP) in the ambient air of urban Kuala Lumpur (KL) based on a passive sampling method with a Tenax® GR adsorbent tube. Analysis of BTEX was performed using a thermal desorption (TD)-gas chromatography mass spectrometer (GCMS). OFP was calculated based on the Maximum Incremental Reactivity (MIR). Results from this study showed that the average total BTEX during the sampling period was 66.06 ± 2.39 μg/m3. Toluene (27.70 ± 0.97 μg/m3) was the highest, followed by m,p-xylene (13.87 ± 0.36 μg/m3), o-xylene (11.49 ± 0.39 μg/m3), ethylbenzene (8.46 ± 0.34 μg/m3) and benzene (3.86 ± 0.31 μg/m3). The ratio of toluene to benzene (T:B) is > 7, suggesting that VOCs in the Kuala Lumpur urban environment are influenced by vehicle emissions and other anthropogenic sources. The average of ozone formation potential (OFP) value from BTEX was 278.42 ± 74.64 μg/m3 with toluene and xylenes being the major contributors to OFP. This study also indicated that the average of benzene concentration in KL was slightly lower than the European Union (EU)-recommended health limit value for benzene of 5 μg/m3 annual exposure.

Heavy metals are widely used in various industries and became a great concern all over the world due to environmental contamination. This study provides an assessment of seasonal variability and risks to human health associated with the exposure to heavy metals concentrated in Langat river water of Malaysia. The Department of Environment (DOE) Malaysia kindly provided the heavy metal concentration data in water for this study. Several multivariate estimation such as an independent t test, box-and-whisker plot and Principal component analysis were carried out to evaluate the seasonal variation of metals concentration in water. The average value of ten analyzed metals was 250.81 µg/l and followed in order of abundance by August > Jun > February > October > April > December > March > May > September > January > July > November. The calculated HPI was 123.42, which is far above the critical index value of 100, indicating pollution with respect to heavy metals. Estimates of health risks associated with river water were summarized according to non-carcinogenic and carcinogenic health effects. No potential threat was detected for noncarcinogenic risk as the HI values calculated were

Mass-spectrometry-based and X-ray fluorescence-based techniques have allowed the study of the distribution of Zn2+ ions at extracellular and intracellular levels over the past few years. However, there are some issues during purification steps, sample preparation, suitability for quantification, and the instruments’ availability. Therefore, work on fluorescent sensors based on 8-aminoquinoline as tools to detect Zn2+ ions in environmental and biological applications has been popular. Introducing various carboxamide groups into an 8-aminoquinoline molecule to create 8-amidoquinoline derivatives to improve water solubility and cell membrane permeability is also a recent trend. This review aims to present a general overview of the fluorophore 8-aminoquinoline and its derivatives as Zn2+ receptors for zinc sensor probes. Various fluorescent chemosensor designs based on 8-amidoquinoline and their effectiveness and potential as a recognition probe for zinc analysis were discussed. Based on this review, it can be concluded that derivatives of 8-amidoquinoline have vast potential as functional receptors for zinc ions primarily because of their fast reactivity, good selectivity, and bio-compatibility, especially for biological applications. To better understand the Zn2+ ion fluorophores’ function, diversity of the coordination complex and geometries need further studies. This review provides information in elucidating, designing, and exploring new 8-amidoquinoline derivatives for future studies for the improvement of chemosensors that are selective and sensitive to Zn2+.

Lack of treated water system in Sabah has increase human dependency to groundwater sources. The presence of contaminants such as nitrate in groundwater can pose severe health implications to human, such as methemoglobinemia and cancerous diseases. The objectives of this paper were to quantify the nitrate concentration in groundwater, to calculate potential human health risk exposure of nitrate in groundwater and to compare the potential human health risk exposure of nitrate between rural and agriculture areas. Six tube wells were selected at Inanam and Kota Belud district and involved one-hundred eighty respondents aged from 7 to 12 years old. The groundwater samples were analyzed using Cadmium Reduction method of HACH DR2800 Spectrophotometer and human health risk exposure were assessed using Chronic Daily Intake (CDI) and Hazard Index (HI) after set of information of respondents were obtained by questionnaires. Result obtained were showing mean ± S.D of nitrate levels in groundwater well and filtered water of agriculture (0.79 ± 0.33 mg/L; 0.33 ± 0.29 mg/L) and rural (0.50 ± 0.12mg/L; 0.53 ± 0.10 mg/L) areas were within the acceptable value limit set by National Drinking Water Quality Standard of Malaysia (10 mg/L). The statistical analysis of Kruskal-Wallis and one-way ANOVA test implied there were no significant differences of nitrate levels between two areas (p>0.05). Moreover, the mean ± S.D of CDI for agriculture and rural areas were 0.0064 ± 0.0056 mg/kg/day 0.0140 ± 0.0096 mg/kg/day respectively and HI were less than 1. The insignificant differences of potential human health risk were noted in terms of gender and age of respondents between two areas. This specified that the human health risk of respondents involved in this study was in acceptable range and not exposed to severe health risks.

The presence of toxic polonium-210 (Po-210) in the environment is due to the decay of primordial uranium-238. Meanwhile, several studies have reported elevated Po-210 radioactivity in the rivers around the world due to both natural and anthropogenic factors. However, the primary source of Po-210 in Langat River, Malaysia might be the natural weathering of granite rock along with mining, agriculture and industrial activities. Hence, this is the first study to determine the Po-210 activity in the drinking water supply chain in the Langat River Basin to simultaneously predict the human health risks of Po-210 ingestion. Therefore, water samples were collected in 2015&ndash, 2016 from the four stages of the water supply chain to analyze by Alpha Spectrometry. Determined Po-210 activity, along with the influence of environmental parameters such as time-series rainfall, flood incidents and water flow data (2005&ndash, 2015), was well within the maximum limit for drinking water quality standard proposed by the Ministry of Health Malaysia and World Health Organization. Moreover, the annual effective dose of Po-210 ingestion via drinking water supply chain indicates an acceptable carcinogenic risk for the populations in the Langat Basin at 95% confidence level, however, the estimated annual effective dose at the basin is higher than in many countries. Although several studies assume the carcinogenic risk of Po-210 ingestion to humans for a long time even at low activity, however, there is no significant causal study which links Po-210 ingestion via drinking water and cancer risk of the human. Since the conventional coagulation method is unable to remove Po-210 entirely from the treated water, introducing a two-layer water filtration system at the basin can be useful to achieve SDG target 6.1 of achieving safe drinking water supplies well before 2030, which might also be significant for other countries.

Integrated Langat River Basin Management lacks appropriate leadership of appropriate agency due to the conflict among jurisdictions since Langat River drains through three different constituency. Meanwhile, pollution of the river and frequent shutdown incidents of water treatment plants in the basin are evident due to both point and non-point sources of pollutions. Moreover, the statistically significant trend of annual rainfall (2005-2016) and temperature (2005-2016) in the basin clearly indicates the impact of climate change because of uncertain rainfall and temperature patterns. Flood incidents (2004-2016) within the basin in comparison with the rainfall and temperature also indicate short duration heavy rainfall at local level to enhance the pollution of the river. Contrary, the review of literature and informal interviews with the public, private and civil sectors highlight the attitude problem of the stakeholders along lack of leadership of LUAS in managing the river and drinking water in the basin. Therefore, the ‘proactive’ leadership of Local Authority under the Local Government Act 1976 could be successful to coordinate with stakeholders through multi stakeholders’ platform and several stages of quality control and quality assurance to manage water resources. The study suggests a new Langat Basin Management Authority under the Local Authority leadership as well as a Two-Layer water filtration technology in basin management. Henceforth, implementing the recommendations will facilitate Malaysia to achieve SDGs 2030 and National Transformation 2050 within the stipulated timeframe.

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.

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.

Received May 7, 2009; Accepted Aug 25, 2009 Published online in J-STAGE Oct 16, 2009 Correspondence to: G.C. Ta, Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia (UKM), 43600 UKM BANGI, Selangor, Malaysia (e-mail: gohchoota@ukm.my) Model for the Implementation of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS): Lessons Learned from Japan