Pesticides In Rice Research Articles

A Study on the Safety of Residual Pesticides in Cereal Grains and Pulses Agricultural Products Excluding Rice

A Study on the Safety of Residual Pesticides in Cereal Grains and Pulses Agricultural Products Excluding Rice

Handheld SERS coupled with QuEChERs for the sensitive analysis of multiple pesticides in basmati rice

Pesticides are a safety issue globally and cause serious concerns for the environment, wildlife and human health. The handheld detection of four pesticide residues widely used in Basmati rice production using surface-enhanced Raman spectroscopy (SERS) is reported. Different SERS substrates were synthesised and their plasmonic and Raman scattering properties evaluated. Using this approach, detection limits for pesticide residues were achieved within the range of 5 ppb-75 ppb, in solvent. Various extraction techniques were assessed to recover pesticide residues from spiked Basmati rice. Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERs) acetate extraction was applied and characteristic spectral data for each pesticide was obtained from the spiked matrix and analysed using handheld-SERS. This approach allowed detection limits within the matrix conditions to be markedly improved, due to the rapid aggregation of nanogold caused by the extraction medium. Thus, detection limits for three out of four pesticides were detectable below the Maximum Residue Limits (MRLs) of 10 ppb in Basmati rice. Furthermore, the multiplexing performance of handheld-SERS was assessed in solvent and matrix conditions. This study highlights the great potential of handheld-SERS for the rapid on-site detection of pesticide residues in rice and other commodities.

Analysis of Pesticide Residues in Water, Rice, Fruits and Vegetables

Pesticides have played a major role in increasing agricultural output by pest control and eliminating insect driven illnesses. Kerala’s tragedy on endosulfan exposure made us to study pesticides in water, rice, fruits and vegetables from Thiruvananthapuram location. Rice (the main cereal consumed in Kerala), fruits, and vegetables, as well as water samples from wells and streams in the Thiruvananthapuram districts, were collected for analysis of residue levels in major food items consumed by people in Kerala. The research was carried out to measure the concentration of organochlorine, organophosphorus, and synthetic pyrethroid pesticides using gas chromatography. The water and food samples collected were analysed for pesticide residues and the quantities were estimated using GC-ECD/NPD. A standard mixture containing Pesticides (OCs, OPs, Pyrethroids, and carbamates) was run before the actual samples. The detection was used to estimate the residues of fifteen commonly used pesticides, namely organochlorine pesticides (endosulfan, dieldrin, aldrin, lindane, DDT), organophosphorus pesticides (chlorpyrifos, profenophos, quinalphos, dimethoate, phorate) and synthetic pyrethroid pesticides (cypermethrin, fenvalerate, deltamethrin, carbofuran). The study concluded that food exposure to pesticides would result in unacceptable health hazards and awareness of pesticide residues in foodstuffs, as well as to quantify the possible health. Hence, necessary to maintain the survey of pesticide residues in all food commodities in order to safeguard the consumers.

Simultaneous determination of eight carbamate pesticide residues in tomato, rice, and cabbage by online solid phase extraction/purification-high performance liquid chromatography-tandem mass spectrometry

建立了在线固相萃取/净化-高效液相色谱-串联质谱(online SPE-HPLC-MS/MS)同时测定番茄、大米和圆白菜中8种氨基甲酸酯类农药的分析方法。将番茄5.0 g(不加水)、圆白菜和大米各2.0 g(各加3 mL水),以1000 r/min旋涡1 min,加入2 g氯化钠和10 mL 0.5%(v/v)甲酸乙腈溶液,旋涡均匀后离心,上清液氮吹后用10%(v/v)乙腈水溶液复溶,复溶液使用CAPCELL PAK C18净化柱(50 mm×2.0 mm, 15 μm)进行在线净化,当流动相0.1%(v/v)甲酸水溶液和乙腈的体积比分别为90:10和35:65时,可实现氨基甲酸酯农药的吸附和洗脱。以ACQUITY UPLC CSH C18色谱柱(100 mm×2.1 mm, 1.7 μm)为分析柱,实现8种氨基甲酸酯类农药的分离,以0.1%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,在12.0 min内即可完成分析。在优化条件下,8种氨基甲酸酯类农药在各自线性范围内线性良好,相关系数均大于0.995, LOD和LOQ分别为0.01~0.3 ng/mL和0.05~1.0 ng/mL;在3个加标水平下,8种氨基甲酸酯类农药的加标回收率为73.76%~112.32%,相对标准偏差为1.28%~13.14%(n=6)。通过在线净化的方式,大大提高了前处理效率,只需12 min即可完成净化上样,不需氮吹复溶等步骤,提高了处理效率。该法回收率高,重复性好,具有准确、快速、灵敏、环保等优点,可用于植物性食品中8种氨基甲酸酯类农药的检测。

Uptake, translocation, and subcellular distribution of three triazole pesticides in rice.

Triazole pesticides are widely used for the control of pathogenic fungi in crops, which were frequently detected in edible parts. Its extensive use has caused many environmental pollution and food safety problems. In this study, the uptake, translocation, and subcellular distribution of three triazole pesticides (triadimefon, tebuconazole, and epoxiconazole) in rice were investigated. The results showed that the three triazole pesticides could be taken up by rice roots, but their distribution in plant tissues were different. The accumulation of the three pesticides in rice root followed the order of epoxiconazole (4.26mg/kg, 24h) > tebuconazole (2.63mg/kg, 24h) > triadimefon (1.37mg/kg, 24h), while a reversed order was observed in rice shoots, triadimefon (0.48mg/kg, 24h) > tebuconazole (0.40mg/kg, 24h) > epoxiconazole (0.21mg/kg, 24h). The translocation of triazole pesticides within rice tissues involved both symplast and apoplast pathways, with triadimefon preferentially through by the apoplast pathway and epoxiconazole through by the symplast pathway. The proportions of triadimefon, tebuconazole, and epoxiconazole in the symplast and apoplast of rice plants were 15-33%, 6-31%, 7-37%, and 67-85%, 69-94%, 63-93%, respectively. The subcellular distribution revealed that all pesticides have a higher proportion in cell walls than in cell organelles and soluble components. Epoxiconazole has the highest accumulated capacity in the cell wall (45-67%) and triadimefon was more concentrated in the soluble components (24-29%). However, there were no significant differences in the amount of three pesticides in cell organelles. The distribution of the three pesticides in aboveground and underground parts of rice plant, uptake and transportation in symplast and apoplast pathways, and distribution in the subcellular tissue are all related to their hydrophobicity.

Drone simulation for agriculture and LoRa based approach

Spraying appropriately and regularly will help develop rice plants' growth and development to produce superior rice. These pesticides' spraying is sometimes uneven because of the vast land, limited human labor, and several other factors. that appropriate technology is needed that helps in the process of spraying rice pesticides using drones. Drones are deemed appropriate in spraying its advantages, among others, more effective, reducing the involvement of humans in work. Drones help track consistently and in detail the part of agricultural land that will be sprayed with pesticides, unlike humans. It is more automatic in monitoring, with the camera used on the drone can see the growth of rice plants directly and do recording or real-time connecting to the application server or IoT. Besides spraying pesticides, regular monitoring of plants can be done with drones. This study uses a UAV simulation for mapping the location of pesticide spraying, the results of contributions to large areas, and analysis of drone power consumption, which means allocating Drones to the area of land being managed.

Bio-efficacy of Unmanned Aerial Vehicle based spraying to manage pests

An agricultural spraying system for UAV platform was developed at the Department of Farm Machinery and Power Engineering, Punjab Agricultural University, Ludhiana during 2019 to spray pesticides in cotton, rice and moong crops for the control of pests. The developed aerial spraying system was operated at three flying speeds, i.e. S1 (2.0 m/s), S2 (3.0 m/s) and S3 (4.0 m/s) and at three flying heights, i.e. H1 (0.50 m), H2 (0.75 m) and H3 (1.0 m). Whitefly and brown plant hopper (BPH) were the targeted pest and its bio-efficacy data were collected after spray application. Results indicated that flying height and forward speed had significant effect on bio-efficacy in all the three crops. In cotton, whitefly populations varied between 19.00-21.40 per three leaves. The maximum percent, i.e. 84.85% reduction in white fly population was observed at 7 DAS in H1S1 treatment. In rice, BPH population was varied between 6.60-9.47 per hill followed by control 17.20 per hill. Maximum percent reduction in BPH population was observed 67.42% at 7 DAS in H3S1 treatment. In moong, reduction in whitefly population was varied between 4.87-5.80 per plant followed by control (7.00 per plant). After three days of spray, combination of flying heights (H1, H2 and H3) and forward speeds (S1, S2 and S3) were found to be significantly effective in dropping whitefly and BPH population. Increase in flying height and forward speed reduced percentage reduction of pests. Combination of flying heights H1 and H2 and forward speeds S1 and S2 treatments were found significantly effective in controlling pests in all three crops.

Evaluation of the automated micro-solid phase extraction clean-up system for the analysis of pesticide residues in cereals by gas chromatography-Orbitrap mass spectrometry

Food analysis is a tremendously broad field that is constantly evolving. New methods have emerged to increase productivity, such as modern miniaturized and robotic analytical techniques. In this paper, a micro-solid-phase extraction system (µ-SPE) for clean-up was combined with a robotic autosampler to yield ready-to-analyze extracts. The system was evaluated for its applicability in routine laboratories. The new, automated, high-throughput µ-SPE clean-up method was applied to acetonitrile extracts and was developed for the analysis of pesticide residues in cereals by gas chromatography-Orbitrap mass spectrometry (GC-Orbitrap-MS). The µ-SPE clean-up efficiency was demonstrated in the removal of matrix-interfering components and in the recovery of pesticides. The sorbent bed mixture consisted of magnesium sulfate, primary-secondary amine, C18, and CarbonX, and effectively retained matrix components without loss of target analytes. Analysis of five types of cereals (barley, oat, rice, rye, and wheat) by GC-Orbitrap-MS showed that the method removed more than 70% of matrix components. The clean-up method was validated for 170 pesticides in rye, 159 pesticides in wheat, 142 pesticides in barley, 130 pesticides in oat, and 127 pesticides in rice. Spike recovery values were 70–120% for all pesticides and the repeatability, calculated as the relative standard deviation, was less than 20%. The limits of quantitation achieved were 0.005 mg kg−1 for almost all analytes, ensuring compliance with the maximum residue limits.

Determination of inorganic arsenic, heavy metals, pesticides and mycotoxins in Indian rice (Oryza sativa) and a probabilistic dietary risk assessment for the population of Saudi Arabia

In this study, total arsenic (As), inorganic arsenic (iAs), cadmium (Cd), lead (Pb), mercury (Hg), pesticides, and aflatoxins (B1, B2, G1, G2) in Indian rice (Oryza sativa) and their dietary exposure risks for the general Saudi population were evaluated. A total of 483 samples were acquired from various ports and supermarkets throughout the country. Average elemental concentrations were found to be in the following order: As (0.1 ± 0.024)>iAs (0.038 ± 0.015)>Pb (0.023 ± 0.008)>Cd (0.019 ± 0.005)>Hg (0.002 ± 0.0004), and results did not exceed maximum residue limits (MRLs). Out of the 294 analyzed pesticides, 15 were detected in rice, of which six were fungicides, and nine were insecticides with a detection frequency of 22% and 26%, respectively. Eight of the detected pesticides were non-approved by the European Union (EU) commission, but their detection frequencies were low. Surprisingly, rice samples analyzed for aflatoxins were below the limit of quantification (LOQ). Risk assessment coupled with Monte Carlo simulation based on the hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) approaches revealed that exposure to metal(loid)s and pesticides in rice were below levels that might pose a health risk.

Determination of 72 Chemical Pesticides and Estimation of Measurement of Uncertainty in Rice Using LC-MS/MS and GC-MS/MS

A multi-residue method was developed and validated for the simultaneous determination of 39 and 33 chemical pesticides in rice using LC-MS/MS and GC-MS/MS, respectively. The coefficient of determination was 0.994 to 0.999 over the linear concentration range of 0.01 to 0.1 μg mL-1. The LOD and LOQ were in the range of 0.31 to 3.35 and 1.04 to 10.06 μgkg-1, repsectively. The mean recoveries at 0.01, 0.05, and 0.1 mgkg-1 were found within the range 70 to 120% with satisfactory precision (RSD < 15%). Measurement uncertainty (Uexp) values estimated at 0.05 mgkg-1 spiking level were found lower than 20 μgkg-1 for all tested pesticides. A rice and wheat powder check samples under the proficiency test were analyzed using a standardized method, and the Z score recorded within the acceptable range of −2 to +2. The proposed method was applied to analyze the pesticides in real samples collected from the market and quantified the residues. The developed method could be useful for monitoring 72 chemical pesticides in rice matrices and can be adopted for the pesticide monitoring program.

Fate and health risks assessment of some pesticides residues during industrial rice processing in Argentina

The residues of deltamethrin, penconazole, kresoxim-methyl, cyproconazole, epoxiconazole and azoxystrobin were determined in husk rice, brown rice, husk and bran, fifty samples of each matrix, obtained from industrial rice facilities, to estimate the distribution of contamination levels during industrial rice processing; and to estimate the exposure to these pesticides through rice intake. The analytical methodologies required were validated. QuEChERS extraction and gas chromatography-mass spectrometry were used. All methods showed good linearity (r2 > 0.9996), adequate recoveries (between 80.0–102.0%) and relative standard deviations lower than 9.9 %. A total of 250 samples were analyzed, finding that the polishing stage reached the greatest pesticide reduction. Considering the overall process, the initial concentration of pesticides in husk rice was reduced in the range of 66.1–74.7%. Process factors were lower than 0.69 and 0.36 for brown and polished rice, respectively. Estimated Dietary Intake were below 0.83 %, 2.34 % and 3.70 % of ADI, for men, women, and children, respectively. Hazard quotient was estimated, and it was lower than 1 in all cases, showing a low potential risk for human health in terms of residue ingestion.

Evaluation of thiobencarb runoff from rice farming practices in a California watershed using an integrated RiceWQ-AnnAGNPS system

The development of modeling technology to adequately simulate water and pesticide movement within the rice paddy environment faces several challenges. These include: (1) adequately representing ponded conditions; (2) the collection/implementation of temporal/spatial pesticide application data at field scales; (3) the integration of various mixed-landuses simulation schemes. Currently available models do not fully consider these challenges and results may not be sufficiently accurate to represent fate and transport of rice pesticides at watershed scales. Therefore, in this study, an integrated simulation system, “RiceWQ-AnnAGNPS”, was developed to fully address these challenges and is illustrated in a California watershed with rice farming practices. The integrated system successfully extends field level simulations to watershed scales while considering the impact of mixed landuses on downstream loadings. Moreover, the system maintains the application information at fine spatial scales and handles varying treated paddy areas via the “split and adjust” approach. The new system was evaluated by investigating the fate and transport of thiobencarb residues in the Colusa Basin, California as a case study. Thiobencarb concentrations in both water and sediment phases were accurately captured by the calibrated RiceWQ model at the edge of field. After spatial upscaling, the integrated system successfully reflected both the seasonal pattern of surface runoff and the timing of monthly thiobencarb loadings. Incorporating future enhancements can further improve model performance by including more detailed water drainage schedules and management practices, improving the accuracy of summer runoff estimations, and incorporating a more sophisticated in-stream process module. This integrated system provides a framework for evaluating rice pesticide impacts as part of a basin level management approach to improve water quality, which can be extended to other rice agrochemicals, or other areas with fine-scale spatial information of pesticide applications.

Quantitative and Confirmatory Analysis of Pesticide Residues in Cereal Grains and Legumes by Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry.

For controlling pesticide residues in food and ensuring food safety, multiresidue methods that can monitor a wide range of pesticides in various types of foods are required for regulatory monitoring. In this study, to demonstrate the applicability of liquid chromatography–quadrupole time-of-flight mass spectrometry (LC–QTOF-MS) for quantitative and confirmatory analysis of pesticide residues in cereal grains and legumes, the LC–QTOF-MS method using full-scan acquisition was validated for 151 pesticides in brown rice, soybeans, and peanuts at a spiked level of 0.01 mg/kg. With the exception of 5 out of 151 target pesticides, sufficiently high signal intensities were obtained at 0.005 μg/mL (corresponding to 0.01 mg/kg). Trueness was in the range 70–95%, with intra- and inter-day precisions below 16% and 24%, respectively, with the exception of 7 pesticides in brown rice, 10 pesticides in soybeans, and 9 pesticides in peanuts. No interfering peaks were observed near the retention times of the target pesticides. Furthermore, information on accurate fragment-ion masses obtained by a data-independent acquisition enabled unambiguous confirmation. The results suggest that the LC-QTOF-MS method is suitable for pesticide residues’ analysis of cereal grains and legumes, and can be utilized for regulatory routine analysis.

A paper-based colorimetric sensor array for discrimination and simultaneous determination of organophosphate and carbamate pesticides in tap water, apple juice, and rice.

A colorimetric paper-based sensor is proposed for the rapid monitoring of six major organophosphate and carbamate pesticides. The assay was constructed by dropping gold and silver nanoparticles on the hydrophilic zones of a paper substrate. The nanoparticles were modified by L-arginine, quercetin, and polyglutamic acid. The mechanism of sensing is based on the interaction between the pesticide and the nanoparticles. The color of nanoparticles changed during the interactions. A digital camera recorded these changes. The assay provided a unique response for each studied pesticide. This method can determine six individual pesticides including carbaryl, paraoxon, parathion, malathion, diazinon, and chlorpyrifos. The limit of detection for these pesticideswere 29.0, 22.0, 32.0, 17.0, 45.0, and 36.0ngmL-1, respectively. The assay was applied to simultaneously determine thesix studied pesticides in a mixture using the partial least square method (PLS). The root mean square errors of prediction were 11, 8.7, 9.2, 10, 12, and 11 for carbaryl, paraoxon, parathion, malathion, diazinon, and chlorpyrifos, respectively. The paper-based device can differentiate two types of studied pesticide (organophosphate and carbamate) as well as two types of organophosphate structures (oxon and thion). Furthermore, this sensor showed high selectivity to the pesticides in the presence of other potential species (e.g., metal ions, anions, amino acids, sugar, and vitamins). This assay is capable of determining the pesticide compounds in tap water, apple juice, and rice samples.Graphical abstract.

Pesticide selectivity to the parasitoid Trichogramma pretiosum: A pattern 10-year database and its implications for Integrated Pest Management

Trichogramma pretiosum is one of the main egg parasitoids used in the control of lepidopteran pests in Brazil. This natural enemy can be negatively affected by the use of insecticides, herbicides, and fungicides. The present work used a systematic review and meta-analysis to group information from multiple studies on the selectivity of pesticides (279 commercial products) in rice, corn, soybean, apple and peach crops for immature stages (egg-larva, pre-pupa, and pupa) and adult parasitoids. The selected studies used the International Organization for Biological and Integrated Control (IOBC) methodology with the same adaptations for T. pretiosum. The meta-analysis found that corn crops had the highest frequency of tests (2 0 7). The most frequently tested active ingredients (a.i.) were glyphosate, glyphosate isopropylamine salt, and sulfur at frequencies of 41, 32 and 24 tests, respectively. The pesticides registered for rice crops showed the greatest sublethal effects on T. pretiosum, with an approximately 47% reduction in parasitism (RP) or emergence (RE). The adult stage of the parasitoid showed greater sensitivity to the tested pesticides (65% RP), in comparison to the immature stages. In general, insecticides showed superior toxicity for all development stages of T. pretiosum, compared to herbicides and fungicides, regardless of the recommended dosage for the crop. The present study aggregates information related to selectivity for the four life stages of T. pretiosum, contributing significantly to the integration of biological control and chemical control in rice, corn, soybean, apple and peach crops in Brazil.

Evaluation of LC-MS/MS methodology for determination of 179 multi-class pesticides in cabbage and rice by modified QuEChERS extraction

A method using modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) without clean-up step based on the sample dilution approach followed by the liquid chromatography coupled with the tandem mass spectrometry (LC-MS/MS) has been established for determination of 179 pesticide residues in cabbage and rice samples. Two different LC columns were used and their sensitivity was investigated regarding the sample volume. Evaluation of the matrix effect in context of sample dilution and applied extraction solvents was investigated. The method was validated according to Document SANTE/12682/2019. For cabbage samples, recoveries were 70–120% for concentration level of 5 μg/kg; and 70–115% for concentration level of 50 μg/kg; precision RSDr <17%; limits of detection and quantification were in the ranges of 0.4–5.5 and 1.2–16.7 μg/kg, respectively. For rice samples, recoveries were 70–109% for 10 μg/kg concentration; 70–115% for 100 μg/kg concentration; precision RSDr <14%, while limits of detection and quantification were in the ranges of 0.5–4.2 and 1.5–12.7 μg/kg, respectively.

Predicting rice pesticide fate and transport following foliage application by an updated PCPF-1 model

The Pesticide Concentration in Paddy Field (PCPF-1) model has been successfully used to predict the fate and transport of granular pesticides applied to the paddy fields. However, it is not applicable for pesticides in foliar formulation while previous studies have reported that foliar application may increase the risks of rice pesticide contamination to the aquatic environment due to pesticide wash-off from rice foliage. In this study, we developed and added a foliar application module into the PCPF-1 model to improve its versatility regarding pesticide application methods. In addition, some processes of the original model such as photodegradation were simplified. The updated model was then validated with data from previous studies. Critical parameters of the model were calibrated using the Sequential Uncertainty Fitting version 2 (SUFI-2) algorithm. The calibrated model simulated pesticide dissipation trend and concentrations with moderate accuracy in the two paddy compartments including rice foliage and paddy water. The accuracy of the predicted soil concentrations could not be evaluated since no observed data were available. Although the p-factor and r-factor obtained using the SUFI2 algorithm indicated that the uncertainty encompassed in the predicted concentrations was rather high, the daily predicted pesticide concentrations in rice foliage and paddy water were satisfactory based on the NSE values (0.36–0.89). The updated PCPF-1 model is a flexible tool for the environmental risk assessment of pesticide losses and the evaluation of agricultural management practices for mitigating pesticide pollution associated with rice production.

Determination of Organophosphate Pesticide Residues in Rice by Multiresidue Analysis

An analytical method was developed for determination of 47 organophosphate pesticides in rice by using solid-phase extraction for clean up. Pesticides in rice samples were extracted with acetone. The extract was cleaned up with 1 g C18 solid-phase extraction (SPE) cartridges and the pesticides were determined using a gas chromatography-flame photometric detector (GC-FPD).The recoveries of 47 pesticides ranged from 74%-126% and the detection limits were 0.005 - 0.04 μg/g. Several pre-treatment methods are compared for the simultaneous analysis of organophosphorus pesticides in rice. Cleanup with SPE showed results comparable to or better than those obtained by liquid-liquid extraction. The SPE method enhances the effect and reduces analytical cost and time.

Determination of butachlor and pencycuron residues in vegetables and rice: Application of the Macroporous Diatomaceous Earth Column

Butachlor and pencycuron are commonly used pesticides in Taiwan, but still lack official methods for determining butachlor and pencycuron residues in agricultural products. An analytical method using a macroporous diatomaceous earth (MDE) column and florisil cartridge for cleanup procedure was developed for determination of butachlor and pencycuron in vegetables and rice. Butachlor and pencycuron were extracted from crops with acetone and the concentrated extract was transferred into the MDE column, eluted with n-hexane. The eluate was concentrated and applied on a florisil cartridge. The cartridge was washed with 5% diethyl ether in n-hexane (E/H), and then eluted with 15% E/H (fraction I) and 15% ethyl acetate in n-hexane (EA/H) (fraction II). Butachlor residue in fraction I was determined by GC-ECD. Pencycuron residue in fraction II was determined by HPLC-UV at 248 nm. Chinese mustard and rice samples were fortified with butachlor and pencycuron at levels of 0.25∼0.75 ppm and analyzed. The recoveries of butachlor and pencycuron were between 84.9∼94.9% and 88.3∼94.8%, respectively. The detection limits of both pesticides in Chinese mustard and rice were 0.05 ppm. MDE liquid/liquid extraction cartridges provide a means of simplifying and speeding up multiple liquid/liquid extractions.

Presence and Health Risks of Obsolete and Emerging Pesticides in Paddy Rice and Soil from Thailand and China.

Organochlorine (OCPs) and organophosphorus pesticides (OPPs) have been intensively applied in rice paddy field farming to control pest infestation and increase the yield. In this study, we investigated the presence of organochlorine and organophosphorus pesticides in paddy rice and soil from rice plantations in Thailand and China. According to concentration and distribution of OCPs, the most abundant OCPs residues in rice and soil from Thailand and China were dichlorodiphenyltrichloroethane and hexachlorocyclohexanes. The OPPs of methidathion, carbophenothion, chlorpyrifos, and diazinon were common to Thailand and China in both types of samples. The detection frequency of multiple types of these pesticides was greater than 50% of total samples. The relative concentration of some OPPs residues in rice and soil from Thailand and China were significantly different from each other (p < 0.0083), whereas, no significant difference was observed for the relative concentration of OCPs residues in rice and soil from both countries, except for HCHs (p < 0.05). Bioaccumulation factors of OCPs between rice and soil samples indicated that OCPs and OPPs in soil could accumulate in rice. The carcinogenic and non- carcinogenic risks of OCPs and OPPs seem to be in the safe range as recommended by the European Union.