Papers by Somporn Chantara
Chiang Mai Journal of Science
ABSTRACT
Comparative studies on polycyclic aromatic hydrocarbon (PAH) pollution in residential air of Hang... more Comparative studies on polycyclic aromatic hydrocarbon (PAH) pollution in residential air of Hangzhou (China) and Shizuoka (Japan) were conducted in summer (August, 2006) and winter (January, 2007). Total concentrations of 8 PAHs ranged from 7.1 to 320 ng/m 3 and 0.15 to 35 ng/m 3 in residential air of Hangzhou and Shizuoka, respectively. Air PAH concentrations in smoking houses were higher than that in nonsmoking houses. In nonsmoking houses, mothball emission and cooking practice were the emission sources of 2-and 3-ring PAHs in Hangzhou, respectively. The 2-and 3-ring PAHs were from use of insect repellent, kerosene heating and outdoor environment in nonsmoking houses in Shizuoka. The 5-and 6-ring PAHs in residential air were mainly from outdoor environment in both cities. Toxicity potencies of PAHs in residential air of Hangzhou were much higher than that in Shizuoka.
Chiang Mai Journal of Science
In seasonal northeast monsoon, heavy rainfalls caused many natural disasters in the southern east... more In seasonal northeast monsoon, heavy rainfalls caused many natural disasters in the southern east-coast of Thailand. A thorough study of simulations of heavy precipitation phenomena could provide a better understanding of their nature, inducing the better forecasting of similar cases. The cumulus parameterization technique was used to determine the appropriate cumulus physics for a model. Three cumulus parameterization schemes, such as, the Kain-Frisch (KF), the Grill-Devenyi (GD), and the Betts-Miller-Janjic (BMJ) schemes were applied for the Weather Research and Forecasting (WRF-ARW version) modeling system. Their performances were evaluated by validation of the simulated rainfall by mean of calculating the categorical skill scores, such as, frequency bias (BIAS), critical success index (CSI), and equitable threat scores (ETS). The rainfall data observed from the Tropical Rainfall Measuring Mission (TRMM), and the Thai Metrological Department (TMD) were used to verify the rainfall simulation results. During the heavy rainfall events in this study, the maximum rainfalls simulated by KF, GD and BMJ schemes were recorded 146, 120, and 38 mm, respectively, while TRMM showed 187 mm of the maximum rainfall. The specific location of the intense rainfalls and their magnitude were excellently simulated in KF scheme. The positions of the maximum rainfall simulated by KF and GD schemes were also more accurate than the positions simulated by BMJ scheme.. The categorical skill scores evaluation revealed that the KF scheme outperforms the GD and BMJ schemes if heavy precipitation is used as the threshold.
Chiang Mai Journal of Science
The simulation of a severe weather phenomenon, in this case the unprecedented heavy rainfall over... more The simulation of a severe weather phenomenon, in this case the unprecedented heavy rainfall over Mumbai in India on July 26, 2005, was selected for this study. The mesoscale numerical weather prediction model used here utilized the Advanced Research Weather Research Forecast model (version 3.0.1), as developed at the National Center for Atmospheric Research (NCAR) in the USA. The study used the Kian-Fritsch (KF), Betts-Miller-Janjic (BMJ) and Grell-Devenyi ensemble (GD) cumulus parameterization schemes across three nested domain configurations. The precipitation simulation results were compared with rainfall observation data from the Tropical Rainfall Measuring Mission. The NCEP analyses, with a 1 1 degree resolution and 26 levels, were utilized to verify the simulation's resulting large-scale circulation pattern, moisture content and relative humidity fields. The 24-hour simulated cumulative rainfall data was created from the different measurements taken at 0300 UTC on July 27, 2005 over Mumbai. It can be observed that the maximum rainfall simulated from the KF, BMJ and GD schemes at 0000 UTC on July 25, 2005, under the initial conditions, was 48, 64 and 32 cm respectively, while the TRMM shows a maximum rainfall of 32 cm at that time. The centre of maximum rainfall was reduced drastically for all 0000 UTC measurements taken on July 26 (the following day), where the initial condition experiments simulated a rainfall amount of only 16 cm. The specific location of the intense rainfall around Mumbai was very-well simulated in the BMJ for 0000 UTC July 25 initial conditions.
International Journal of Environmental Science and Development, 2016
Open burning is an important source of atmospheric particulate matter (PM) emissions in the South... more Open burning is an important source of atmospheric particulate matter (PM) emissions in the South East Asian Region. PM2.5 samples were collected in dry season (March 2013) at two sampling locations in Chiang Mai Province, Thailand. Doi Ang Khang (DAK) site is located uphill near the Myanmar border representing a near source site and Chiang Mai University (CMU) is located downhill in the city of Chiang
International Journal of Environmental Science and Development, 2014
This research simulated tropospheric ozone in Southeast Asia in dry season (November 2006 – April... more This research simulated tropospheric ozone in Southeast Asia in dry season (November 2006 – April 2007) by WRF-Chem model. NCEP/NCAR Reanalysis and the Model for Ozone and Related chemical Tracers, version 4 (MOZART4) were used as atmospheric and chemical boundary and initial conditions, re-spectively. The Fire INventory from NCAR (FINN) data and the Reanalysis and the TROpospheric chemical composition (RETRO) data were used as Biomass burning emission and anthropogenic emission data, respectively. The model results indicate that ozone concentrations in the cool dry season (November – February) are lower than the warm dry season (March-April).
Analytical methods
The aim of this study was to identify a plasma biomarker of exposure to pyrethroid insecticides. ... more The aim of this study was to identify a plasma biomarker of exposure to pyrethroid insecticides. A major metabolite, 3-phenoxybenzoic acid (3-PBA), can be detected in urine but urinary 3-PBA cannot be used to assess the active dose. The 3-PBA-adduct represents a much more persistent class of biomarkers than metabolites excreted into urine, having half lives up to several weeks or months. We developed an enzyme-linked immunosorbent assay (ELISA) for total 3-PBA including adduct formed after alkaline hydrolysis, liquid-liquid extraction (LLE) and solid phase extraction (SPE) of the sample. The developed ELISA had an IC50 value of 26.7 ng/mL. The intra- and inter-assay coefficients of variation (%CV) were lower than 5% and were within the optimum condition variance (OCV) range. The LLE cleanup technique satisfactorily eliminated the matrix effect from plasma samples before SPE and ELISA analysis yielding good recoveries (85.9-99.4%) with a limit of quantitation (LOQ, 5 ng/mL) that was ...
Advances in Environmental Biology
Environmental Research, 2015
Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse ... more Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse birth outcomes and neurodevelopment. However, the mechanisms of toxicity of OP pesticides on human fetal development have not yet been elucidated. Our pilot study birth cohort, the Study of Asian Women and Offspring's Development and Environmental Exposures (SAWASDEE cohort) aimed to evaluate environmental chemical exposures and their relation to birth outcomes and infant neurodevelopment in 52 pregnant farmworkers in Fang district, Chiang Mai province, Thailand. A large array of data was collected multiple times during pregnancy including approximately monthly urine samples for evaluation of pesticide exposure, three blood samples for pesticide-related enzyme measurements and questionnaire data. This study investigated the changes in maternal acetylcholinesterase (AChE) and paraoxonase 1 (PON1) activities and their relation to urinary diakylphosphates (DAPs), class-related metabolites of OP pesticides, during pregnancy. Maternal AChE, butyrylcholinesterase (BChE) and PON1 activities were measured three times during pregnancy and urinary DAP concentrations were measured, on average, 8 times from enrollment during pregnancy until delivery. Among the individuals in the group with low maternal PON1 activity (n=23), newborn head circumference was negatively correlated with log10 maternal ∑DEAP and ∑DAP at enrollment (gestational age=12±3 weeks; β=-1.0cm, p=0.03 and β=-1.8cm, p<0.01, respectively) and at 32 weeks pregnancy (β=-1.1cm, p=0.04 and β=-2.6cm, p=0.01, respectively). Furthermore, among these mothers, newborn birthweight was also negatively associated with log10 maternal ∑DEAP and ∑DAP at enrollment (β=-219.7g, p=0.05 and β=-371.3g, p=0.02, respectively). Associations between maternal DAP levels and newborn outcomes were not observed in the group of participants with high maternal PON1 activity. Our results support previous findings from US birth cohort studies. This is the first study to report the associations between prenatal OP pesticide exposure and birth outcomes in Thailand.
This study surveyed the exposure to pesticides among farmers in Chiang Mai's highland agricul... more This study surveyed the exposure to pesticides among farmers in Chiang Mai's highland agricultural area. Ethnic Hmong farmers, living in Baan Buak Jan, Mae Rim District, Chiang Mai Province were selected as the study population. Pesticide-specific urinary metabolites were used as biomarkers of exposure to a variety of pesticides, including organophosphorus pesticides, synthetic pyrethroids and selected herbicides. Our method employed
The Science of the total environment, Jan 15, 2008
Our research goal was to assess exposure to currently used pesticides among small-scale male farm... more Our research goal was to assess exposure to currently used pesticides among small-scale male farmers residing in two topographically different areas in Chiang Mai Province, Thailand. Farmers (N=136) were recruited from Pong Yaeng subdistrict (N=67) and Inthakhin subdistrict (N=69). Each farmer provided a morning urine void for the analysis of 30 urinary metabolites of insecticides, herbicides, and fungicides. Farmers in Pong Yaeng had significantly higher urinary concentrations of metabolites of organophosphorus insecticides and ethylene bisdithiocarbamates, while farmers from Inthakhin had significantly higher concentrations of malathion, 2,4-D, alachlor, and parathion or EPN metabolites. Based upon the metabolites measured in the urine of the farmers, chlorpyrifos and pyrethroid insecticides seemed to be commonly used across both communities; no significant differences in metabolite concentrations of these insecticides were observed between the two farmer groups. The presence of m...
Sustainability Today, 2011
ABSTRACT This study was conducted in four intensive agricultural areas of the Fang district, Chia... more ABSTRACT This study was conducted in four intensive agricultural areas of the Fang district, Chiang Mai, northern Thailand. The objective of this study was to determine synthetic pyrethroid residues in vegetable, fruit, sediment, and surface water samples. Fruit and vegetables were purchased from local markets in the study areas. The vegetables in this study included cabbage, kale, water spinach, cauliflower, Chinese cabbage, Chinese mustard, yard long bean, cucumber, and sugar pea, while the fresh fruit included tangerine, guava, apple, dragon fruit, mango, sand pear, rose apple, lychee and grape. Sediment and surface water samples were collected from main streams of the four studied areas. The pyrethroid residues in vegetables, fruit, and sediment samples were extracted with dichloromethane in an ultrasonic bath and cleaned up on a graphite carbon cartridge. Liquid – liquid extraction technique was used to prepare pyrethroid compounds from surface water samples. The extracted samples were determined by using gas chromatography – electron capture detection (GC-ECD). Six synthetic pyrethriod pesticides in this study consist of lambda cyhalothrin, permethrin, cyfluthrin, cypermethrin, fenvalerate, and deltamethrin.
Chiang Mai Journal of Science
Concentrations of airborne particulate matters with diameter less than 10 μm (PM 10) were measure... more Concentrations of airborne particulate matters with diameter less than 10 μm (PM 10) were measured for 24 hours every 3 days at four sampling stations located in Chiang Mai and Lamphun Provinces, Thailand. The sampling scheme was conducted during June 2005 to June 2006. The result revealed the same pattern for all stations, in which the PM 10 concentration increased at the beginning of dry season (December) and reached its peak in March before decreasing by the end of April. The mean PM 10 concentrations were in the range from 33.17 21.39 μg/m 3 in rainy season to 73.64 25.34 μg/m 3 in dry season. The analysis for air pollutants in particulate matters was carried out in order to determine polycyclic aromatic hydrocarbons (PAHs) by GC-MS, major dissolved ions by IC, some metals and elements by ICP-OES and total carbon by CHN/S/O analyzer. Mean concentration of total PAHs was in a range from 1.7 – 12.2 ng/m 3 . Ratio of non-carcinogenic and carcinogenic PAHs found was about 1:3 and 1:...
Atmospheric Environment, 2015
A PTV GC high resolution mass spectrometry method was developed for oxy-PAHs and PAHs. Accelerate... more A PTV GC high resolution mass spectrometry method was developed for oxy-PAHs and PAHs. Accelerated solvent extraction was evaluated as an extraction technique. Recoveries and matrix effects were evaluated for both oxy-PAHs and PAHs. First concentration data for oxy-PAHs on PM10 in Chiang Mai, Thailand. The level of P oxy-PAHs (1.1 ng/m 3 ) is significant when compared to P PAHs (3.4 ng/m 3 ).
Chiang Mai University Journal of Natural Sciences, 2014
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Papers by Somporn Chantara