Rayong Province Research Articles

Microplastic pollution in surface seawater and beach sand from the shore of Rayong province, Thailand: Distribution, characterization, and ecological risk assessment

The distribution, characteristics, and ecological risk of microplastics in beach sand and seawater samples collected along the shore of Rayong province, Thailand, were investigated in this study. The average microplastics abundance in beach sand and seawater was 338.89 ± 264.94 particles/kg d.w. and 1781.48 ± 1598.36 particles/m3, respectively. Beach sand and seawater had the most yellow-brown particles and transparent microfibers, respectively. The most common microplastics (100–500 μm) and polyethylene were found. In beach sand, the potential ecological risk (RI) is classified as minor, while in seawater, it is classified as medium. The PLIzone in beach sand and seawater was Hazard Level II and Hazard Level IV, respectively. Despite their apparent proximity, the non-correlation between risk levels in beach sand and seawater may be due to polymer type variations influenced by the different land-based and sea-based sources.

Spatial and temporal patterns of white spot disease in Rayong Province, Thailand, from october 2015 to september 2018

This study aimed to analyze the spatial and temporal patterns of white spot disease (WSD) in shrimp farms in Rayong Province, Thailand, between October 2015 and September 2018. The longitudinal data of all active shrimp farms were collected and categorized into two groups: cases and non-cases. A space–time permutation scan, epidemic curve, and time-series analysis were used to evaluate the spatiotemporal patterns. We assessed a total of 1126 ponds across 176 farms in two districts (Klaeng and Mueang Rayong) and identified three significant (P < 0.05) clusters of WSD cases. The biggest cluster encompassed 21 geographical coordinates. This cluster had a radius of 1.14 km and occurred between January 31, 2017, and February 28, 2017. The epidemic curve showed that the biggest outbreak peaked from December 2017 to February 2018. In the time-series analysis, the highest probability of actual WSD cases was at the beginning of each calendar year, consistent with the prominent high probability recorded in WSD forecasts. Our analysis presents the interaction between hotspot areas and time period. These results should help the relevant authorities implement appropriate surveillance programs and control measures to limit the occurrence and transmission of WSD.

Type and Distribution of Microplastics in Beach Sediment along the Coast of the Eastern Gulf of Thailand

In the oceans and coasts, plastic waste poses a global threat to biodiversity. This study examined the types and distribution of microplastics in beach sediment along the coast of the eastern Gulf of Thailand in March 2018 (northeast monsoon = dry season) and July 2018 (southwest monsoon = rainy season). Microplastic samples were collected from six stations including Koh Khramyai Beach (Chonburi Province), Koh Mannai Beach (Rayong Province), Chao Lao Beach (Chanthaburi Province, 3 stations), and Ploy Dang Beach (Trat Province). The results showed that the highest average abundances of microplastics in March and July were at Koh Mannai Beach (1698 pieces/m2) and Koh Khramyai Beach (799 pieces/m2), respectively. However, no microplastics were found at Ploy Dang Beach in July. According to polymer-type identification using an FTIR spectrometer, 17 polymer types were found in this study. Polyethylene terephthalate (PET = 39.6%) and polyamide (PA = 22.8%) were the polymer types found in the highest proportions in March and July, respectively. In addition, the fiber shape and transparent color of microplastics were found to be the most abundant.

Nitrogen dioxide exposure and health risk assessments of students in elementary schools in the vicinities of an industrial estate, located in Rayong Province, Thailand

Exposure to nitrogen dioxide (NO2) poses a danger to the health of many children all over the world especially children that attend schools in the vicinities of traffic roads and industries. This research study aims to assess the impacts of NO2 exposure on the health of the students. NO2 samples were collected by tube-type passive samplers. Moreover, the investigation of indoor NO2 exposure of students was associated with physical human health by using multiple logistic regressions. The results revealed that the indoor and outdoor NO2 concentrations in elementary schools were 9.0 ± 4.4 to 16.7 ± 2.7 μg/m3 and 8.2 ± 2.1 to 17.7 ± 6.7 μg/m3, respectively. However, indoor and outdoor values of NO2 were lower than the WHO standard of 40 μg/m3. Non-carcinogenic risk assessments of NO2 were carried out to help assess the health risks of students. It was found that the HQ of all those who studied in schools was less than 1, indicating no health risks. However, NO2 in classrooms can cause eye irritation (p-value = 0.007), pink eye/ allergic conjunctivitis (p-value = 0.012), runny nose (p-value = 0.020), sore throat (p-value = 0.038), wheeze (p-value = 0.022) and cough (p-value = 0.035). Therefore, children who spend time in classrooms close to heavy traffic and petrochemical plants might find themselves exposed to increased health risks.

Case Report: An Eyelid Nodule Caused by Candidatus Dirofilaria hongkongensis Diagnosed by Mitochondrial 12S rRNA Sequence

A 59-year-old female living in Rayong Province, eastern Thailand, presented with painless, right upper eyelid nodule for 3 months. Upon removal of the eyelid mass, a well-circumscribed, firm globular mass with diameter about 1 cm was found. Histopathological examination revealed an immature female dirofilarial worm reminiscent of Dirofilaria repens, characterized by prominent sharp longitudinal ridges at external surface of the cuticle. Analysis of the mitochondrial 12S rRNA sequence showed that the worm belongs to Candidatus Dirofilaria hongkongensis. It is likely that some infections previously reported as D. repens based on histological examination may have actually been due to Candidatus D. hongkongensis.

Improvement of an open sun drying system for dried banana product using solar tracking system: a case study in Thailand

ABSTRACT This paper proposes an open sun drying (OSD) system for dried banana products using automatic dual-axis solar tracking. A pseudo-azimuthal mounting structure is implemented to rotate around the primary (daily angle) and secondary (elevation angle) axes. The proposed drying system uses a simple light-dependent resistor (LDR) orientation to control the rotating axes and follow the sun trajectory. The rotation in the primary axis adjusts the daily angle from east to west, which changes each hour. The secondary axis is rotated for the elevation angle from north to south direction, a seasonal change. The experiment was conducted at the Faculty of Engineering and Technology, King Mongkut’s University of Technology North Bangkok, Rayong Campus, Rayong province, Thailand, to validate the performance of the proposed system compared with two conventional OSD systems: horizontal flat-plate and tilted. The effect of the solar tracking system on the drying characteristics of dried bananas is evaluated by considering moisture content, moisture ratio, drying rate, and drying time. The experimental results demonstrate that the proposed drying system can reduce the drying time for banana products compared with the tilted system by 18.87% and the horizontal flat-plate system by 21.82%. Moreover, the experiment reveals that the electrical energy consumed by the proposed drying system is only 32.26 Wh/day. Finally, the economic analysis confirms that the payback period of the proposed drying system is approximately 0.76 years.

Spatial distribution and health risk assessment of As and Pb contamination in the groundwater of Rayong Province, Thailand

This study investigates the presence of arsenic (As) and lead (Pb) in groundwater and their spatial distribution in Ban Khai District, Rayong Province, Thailand. Forty groundwater samples were collected at different locations in the dry and wet seasons during March and August of 2019, respectively. The hydrochemical facies illustrate that the major groundwater types in both seasons mainly consisted of Ca–Na–HCO3, Ca–HCO3–Cl and Na–HCO3 types. The concentration of As ranged from <0.300 to 183.00 μg/L, accounting for 22% (18 of 80 samples), exceeding the WHO guidelines of 10 μg/L. The spatial distribution of As was distinctly predominant as a hot spot in some areas during the wet season. The wells may have been contaminated from human activity and thus constituted a point source in the adjacent area. For Pb, its concentration in all the wells were not exceeded 10 μg/L of the WHO guidelines, appearing as a background concentration in this area. Most of the wells were shown to be in an oxidation state, supporting AsV mobility. Moreover, the area also had a nearly neutral pH that promoted AsV desorption, while the presence of undissolved Pb in the aquifers tended to increase. Furthermore, chemical applications to agricultural processes could release the As composition into the groundwater. The health risk resulting from oral consumption was at a higher risk level than dermal contact. The non-carcinogenic risk affecting the adult population exceeded the threshold level by approximately 27.5% of the wells, while for the children group, the risk level was within the limit. Total cancer risk (TCR) of adult residents exceeded the acceptable risk level (1 × 10−6) in all wells, causing carcinogenic health effects. Therefore, health surveillance is important in monitoring the toxic effects on the local residents who use groundwater from these contaminated wells. Furthermore, a sanitation service and an alternative treatment of the water supply will be needed, especially in wells with high As levels.

การประเมินคุณภาพน้ำของแม่น้ำคลองใหญ่ จังหวัดระยอง โดยใช้ดัชนีชี้วัดทางเคมี

การประเมินคุณภาพน้ำของแม่น้ำคลองใหญ่ จังหวัดระยอง โดยใช้ดัชนีชี้วัดทางเคมี

A model of participatory learning process for management of environmental health impacts in industrial communities area

PurposeThe purpose of this paper is to implementing environmental education concepts to manage environmental health impacts by letting the people in the community learn through the participatory learning process.Design/methodology/approachThe participatory action research (PAR) and the environmental education concept were conducted in managing the learning process for the people in Map Kha Sub-district, Rayong province. The purposive sampling technique and the stakeholder analysis were used to derive the informants of this study. They are those people living or working in the Mab Kha Sub-district area at least 2 years, aged more than 20 years old, and were willing to participate in all steps of the study. A total of 30 informants were divided into three groups as follows: The Key Informants, The Casual Informants and The General Informants. Data collection employed workshops with three techniques – Participatory Rural Appraisal (PRA), Future Search Conference (FSC) and Appreciation Influence Control (AIC) – to organize cooperative learning processes to managing environmental health impacts. The Content Analysis was utilized in this study through the categorization, grouping, analysis, interpretation and systemization of data. The study period was from June 2014 to December 2015.FindingsThe study found that most people are concerned and aware of the environmental pollution problems affecting the health in the areas and need to solve such problems. They are also prepared for various problems. However, they face the problems on that they still lack of the chance to be informed about the information on the pollution problems and lack of the chance to participate. For the participatory learning process used to manage the environmental health impacts in the industrial community, it is found that the people and the leading network partners perform well through the knowledge building process on the environmental pollution problems and the planning and evaluation lead to desired behavior of people and industrial community to manage environmental health impacts.Originality/valueThe study results emphasized that the participatory learning process of the network associates was the critical key in forming the community power to manage the environmental health impacts. Therefore, the learning process should be easy, not complicated, take a short time and be friendly that will make the community understand the problem and help protect the environment systematically.

Evaluation of Wind Energy Potential in Rayong Province, Thailand by WAsP Program

Over the past decades, Wind energy is one of the alternative energy or renewable sources, which has been harvested to produce electricity. Our research aims to study the wind potential of the areas in the Rayong provinces of Thailand. Data from meteorological stations were collected every 10 minutes for of 3 years (2017-2019), with a measuring tower at 10-meter height above ground level (AGL). The annual average wind speeds were investigated in Rayong (2.02 m/s) with Weibull Probability Distribution Function (PDF). The annual average power density in Rayong regions was 13 W/m2. In all locations, wind direction was detected mainly from Southwest (SSW) and the yearly maximum wind power capacity is 94.376 MWh. The capacity factor of 21.5 % was noticed. With relatively low wind speed was noticed in Rayong provinces of Thailand, a small wind turbine installed at 30 meters would be recommended as a cost-effective way to convert wind power to electricity.

Determination of perfluorooctane sulphonate and perfluorooctanoic acid in seafood and water from Map Ta Phut Industrial Estate area, Thailand

ABSTRACT This initial study aimed to determine the concentrations of perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA) in seafood, bottled drinking water, and surface and tap water collected from Map Ta Phut Industrial Estate in Rayong province, Thailand. Samples were collected during dry (January) and wet (June) seasons, 2019. The perfluorinated compounds were cleaned up by solid phase extraction and analysed by ultra-performance liquid chromatography–tandem mass spectrometry with stable isotopic labelled internal standards (13C8–PFOS and 13C8–PFOA). This study reports concentrations of PFOS and PFOA in seafood at levels between 29–6724 and <48–421 ng/kg wet weight, respectively. Surface water samples from rivers and the coastal sea had PFOS and PFOA between 0.60–465.65 and <0.25–59.29 ng/L, respectively. Contamination of PFOS and PFOA in bottled drinking water (<0.125–0.454 and <0.25–0.621 ng/L, respectively) did not exceed the USEPA standard of 70 ng/L. Concentrations of PFOS and PFOA in seafood and water samples between seasons did not show any definite trend. Seafood dietary assessments of PFOS exposure in the seafood eater population raised a health concern, as the exposure exceeded the latest EFSA tolerable weekly intake value for PFAS mixtures (4.4 ng/kg body weight/week). Therefore, environmental and food samples from Map Ta Phut area should be closely monitored to ensure the safety of people living in and around this area.

Spatial Analysis of Mangrove Forest Area Change in Prasae River Mouth of Rayong Province Using Satellite Imageries

The effect of spatial change on the coastal area affected the status of mangrove forest. Richness of mangrove forest of Prasae estuary has been changed over time due to human activities. This research aimed to use remote sensing technology to investigate the richness of the mangrove forest in the coastal of Prasae estuary in years 2009, 2014, and 2019. Four sub-districts of Klang district, Rayong province were analyzed; namely Paknam Krasae, Pang Rad, Nern Koh, and Klong Pun. Normalized Difference Vegetation Index was evaluated for indicated of biomass that covers land area. The results showed that overall accuracy each year was 80.56, 79.17, and 82.64 %, respectively. The areas of mangrove forest in 2009, 2014, and 2019 were 11,316.48, 18,058.19, and 10,060.86, rai respectively. The prediction of the mangrove forest areas using CA-Markov model indicated that the mangrove area in 2029 would be 7,662.14 rai, which approximately decreases for 23 %

Ambient and Indoor PM10 and PM10-bound PAHs around the Vicinity of an Industrial Estate in Rayong, Thailand: Concentration and Source Identification

The ambient and indoor air concentrations of PM10 and PM10-bound PAHs (16 priority PAHs) were investigated in Rayong Province, Thailand. The locations of the selected study areas were Map Ta Phut Industrial Estate and its vicinity comprising six sampling sites (four industrial areas and two vicinity areas). The indoor and ambient air samples of were collected in March 2017. The sampling sites located close to the road were detected the greatest ambient average concentrations of PM10, with an average value of 56.06 µg m-3 (Map Chalut Area or MC). The levels of indoor PM10 were mostly dependent on the resident activities and the highest mean level of PM10 was 31.29 µg m-3 detected at Huai Pong. The Benzo(b)fluoranthene and acenaphthylene were the major PAHs found to have the highest 24-h average concentrations for both indoor and ambient air. The highest mean ambient and indoor air levels of benzo(b)fluoranthene were 49.18 and 30.88 ng m-3, respectively, found at MC. In terms of 16 total PAHs, MC was found to have the greatest level. Analysis of the diagnostic ratios determined that the traffic density was the major source of influence on particle-bound PAH concentrations for both ambient and indoor air samples, which indicated that the greater the traffic volume, the higher the level of PAHs.

Business Model Canvas Effect Risk Management and Business Performance: SMEs in Rayong, Thailand

This research studied the relationship of business operations based on business elements ofBusiness Model Canvas that influenced the efficiency in risk management and the performanceof SMEs in Rayong province. The research is based on a Quantitative research methodology,where data collection has been achieved through self- administered questionnaires. The statisticalresults found that the Business Model Canvas influenced SMEs performance in Rayong.Theempirical data and correlation testing via Structure Equation Modeling in which found thatSMEsbusinesses in Rayong had well business plan that covered all the nine aspects of Business ModelCanvas with the efficient risk management.Both led to the well Balance Scorecard performanceincluding the well business plan that would lead the business to have good risk managementefficiency. The risk management efficiency was the partial mediation from the Business ModelCanvas to the business performance result.

Effects of Arsenic and Iron on the Community and Abundance of Arsenite-Oxidizing Bacteria in an Arsenic-Affected Groundwater Aquifer

Arsenic (As) contamination of groundwater aquifers is a global environmental problem, especially in South and Southeast Asian regions, and poses a risk to human health. Arsenite-oxidizing bacteria that transform As(III) to less toxic As(V) can be potentially used as a groundwater As remediation strategy. This study aimed to examine the community and abundance of arsenite-oxidizing bacteria in groundwater with various As concentrations from Rayong Province, Thailand using PCR-cloning-sequencing and quantitative PCR (qPCR) of catalytic subunit of arsenite oxidase gene (aioA). Key factors influencing their community and abundance were also identified. The results demonstrated that arsenite-oxidizing bacteria retrieved from groundwater were phylogenetically related to Betaproteobacteria and Alphaproteobacteria. The aioA gene abundances ranged from 8.6 × 101 to 1.1 × 104 copies per ng of genomic DNA, accounting for 0.16-1.37% of the total 16S rRNA bacterial gene copies. Although the abundance of arsenite-oxidizing bacteria in groundwater was low, groundwater with As(III) dominance likely promoted their abundance which possibly played an important role in chemolithoautotrophic oxidation of As(III) to As(V). Fe and As(III) were the major environmental factors influencing the community and abundance of arsenite-oxidizing bacteria. The knowledge gained from this study can be used to further contribute to the development of bioremediation strategies for As removal from groundwater resources.

Measurement of radionuclides in surface soil and beach sand samples from Rayong Province (Thailand) and the evaluation of excess lifetime cancer risk

Measurement of radionuclides in surface soil and beach sand samples from Rayong Province (Thailand) and the evaluation of excess lifetime cancer risk

Preliminary Study of Abundance and Characteristics of Microplastics on Beach Sediment along the Coast of Rayong Province, Thailand

This study concentrates on the beach sediment collected at Suchada (SD), Saeng Chan (SC) and Laem Charoen (LM) beaches in the Rayong province of Eastern Thailand. The samples were collected for a preliminary investigation for microplastic contamination. A total of 18 samples were taken parallel with the shoreline at the depth of 5 centimetres. They were collected between the months of August to September 2019. Density separation, microscopic inspection and ATR-FTIR analysis were conducted to analyze the characteristics of microplastics and the type of polymers. The average concentration of microplastics on three beaches was 568.33 ± 153.05 items per kilogram of dry weight. Based on the categorization according to shape, colour, and size, microfibers accounted for a dominant proportion of microplastics. Blue ( > 45%) and 1,000-5,000 µm particle sizes were the most prevalent microplastics in SC and LM beaches, while red (43%) colour and small microplastics (100-500 µm) were the dominant proportion in SD beach. ATR-FTIR analysis determined that the polymers found in microplastic were polypropylene, polyethylene, low-density polyethylene and cellophane.These results indicated that land-based sources also those including tourism activities, fishery activities, river, and sewage discharge from industrial and urban communities are most likely the main source of microplastics in beach sediment along the coast of Rayong province.

Mechanisms of arsenic contamination associated with hydrochemical characteristics in coastal alluvial aquifers using multivariate statistical technique and hydrogeochemical modeling: a case study in Rayong province, eastern Thailand.

The rapid development of Rayong Province has resulted in increased demands on groundwater usage. This has potentially induced the release of contaminants such as arsenic (As), among others (i.e., NO3-, PO43-) from various land use types-especially in intensive agricultural areas and heavy industrial areas, including landfill sites. The objectives of this research are to investigate the As speciation and groundwater chemistry occurring due to different hydrogeological settings and the influence of human activities and to explain the mechanism of As release in the coastal alluvial aquifers in Rayong Province using multivariate statistical techniques and hydrogeochemical modeling (PHREEQC). Six major water facies, mainly consisting of Ca-Na-HCO3-Cl and Ca-Na-Cl, were included in the hydrochemical analysis. Arsenic levels were inversely correlated with NO3-, SO42-, DO, and ORP, confirming the reducing environment in the groundwater system. The results from the PHREEQC model show that most wells were strongly under-supersaturated with respect to arsenorite, scorodite, and arsenic pentoxide. Arsenic (As) is probably derived from the dissolution of Fe oxide and hydroxide (i.e., Fe(OH)3, goethite, maghemite, and magnetite). The multivariate statistical techniques revealed that the As species mainly consisted of As(III), governed by the reducing environment, while As(V) may be desorbed from Fe oxide and hydroxide as the pH increases. Anthropogenic inputs and intensive pumping may enhance the reducing environment, facilitating the release of As(III) into the groundwater. The knowledge gained from this study helps to better understand the mechanisms of As contamination in coastal groundwater aquifers, which is useful for groundwater management, including the optimum pumping rate and long-term monitoring of groundwater quality.

Assessments of Nipa Forest Using Landsat Imagery Enhanced with Unmanned Aerial Vehicle Photography

Nipa palms are exposed by the transformation of land use and land cover changes (LULCC) due to changes to aquaculture and orchards. Modern remote sensing for environmental monitoring of LULCC has been made easier by the use of high spatial resolution images, innovative image processing and Geographic Information Systems (GIS). The expense of high-resolution satellite imagery has resulted in investigators moving to open sources (e.g., Landsat), therefore, the interpretation of images at a medium resolution can be classified simply as LULCC classes and are constrained by the detection of small-scale disturbances. This research applied Landsat imagery with very high-resolution imagery from Unmanned Aerial Vehicles (UAVs). In order to be useful for real-world applications, the accuracy of remote sensing data must be validated using proven ground-based methods. UAVs equipped with multispectral sensors were flown over the Nipa palms at the Prasae River, Rayong Province, Thailand. The main advantage of UAV-based remote sensing is that it reduces costs and immediate availability of high-resolution data. The UAV imagery was expensed as “drone truthing data” to train image classification algorithms. These results show that UAV data can be used effectively to support and categorize similar land-cover/use classes (aquaculture vs. mangrove forest vs. nipa forest) with consistently high identification of over 87.6% on the generated thematic map, where the mangrove forest detection rate was as high as 86%. For that reason, UAVs are engaged successively in management and conservation tasks, which can be used for regional or local scale studies to compare the achieved accuracy to a general regional land cover map. This approach can be used for the variability of plants to rectify land-cover classification. Therefore, UAV images are a very useful tool to fill the gap between remote sensing information and expensive ground field campaigns.

Analysis of Covering Problem Models for Setting the Location of a Ready-Mixed Concrete Plant: Case Study of the Rayong Province, Thailand

Decision makers must prepare good plans when developing large-scale projects. The Thai government has been increasing economic growth in three provinces under the Eastern Economic Corridor Development Program (EEC). The project includes reconstruction and new construction. This paper aims to find locations for several ready-mixed concrete plants to cover all ready-mixed concrete needs in the Rayong province. The plant location problem could be solved using optimization modelling for a set covering location problem (SCLP) and a maximal covering location problem (MCLP). The results show that two ready-mixed concrete plants location in the Mueang Rayong district and Klaeng district could meet the problem solution.