Montree Ponsin

Bio: Montree Ponsin is an academic researcher from Chulalongkorn University. The author has contributed to research in topics: Environmental chemistry & Contamination. The author has an hindex of 2, co-authored 2 publications receiving 18 citations.

Risk assessment of bioaccessible arsenic and cadmium exposure through rice consumption in local residents of the Mae Tao Sub-district, Northwestern Thailand

Abstract: Consumption of contaminated rice is a toxin exposure route in Asian populations. Since total concentrations generally overestimate health risks, the objectives of this study were to determine the levels of bioaccessible As and Cd in rice cultivated in the Mae Tao, Tak Province and evaluate their potential health impacts in local adults. In total, 59 locally grown rice samples were analyzed for their total and bioaccessible concentrations. Bioaccessible concentrations were obtained from an in vitro digestion process. Inorganic As concentrations were estimated assuming that 63.2-63.5% of the total As is inorganic As. Rice contained inorganic As (45.2% of white rice and 57.1% of sticky rice) and Cd (51.6% of white rice and 32.1% of sticky rice) levels exceeding the Codex standards. The bioaccessibilities of As (16.3-70.0%) and Cd (Null to 83.7%) in rice varied widely. The concentrations of bioaccessible As, which were 1-1.2 times greater than those of bioaccessible Cd, indicate a higher possibility of As absorption into the human body. Positive significant relationships were found between total and bioaccessible As (R2 = 0.568 for white rice and R2 = 0.704 for sticky rice) and Cd (R2 = 0.874 for white rice and R2 = 0.862 for sticky rice). The hazard quotient (HQ) of inorganic As exposure accounted for approximately 93.4% of hazard index (HI). Approximately 2-6 in 10,000 residents over a lifetime of 75 years could suffer from cancer as a result of daily rice consumption. Therefore, the consumption of the home-grown rice in this study should be limited.

Sustainable solutions to arsenic accumulation in rice grown in south and south-east Asia

Abstract: Widespread distribution, toxicity and exposure through rice and rice-based food products make arsenic (As) contamination of environment a serious issue. This review discusses various strategies that can be utilised to tackle the As problem in rice, and the socioeconomic impacts of the As problem. The countries of south and south-east Asia are renowned as hotspots of As contamination owing to occurrence and enrichment of As in soil and groundwater via natural biogeochemical weathering of rocks and As-enriched sediment. The irrigation of rice is mostly applied through the use of contaminated groundwater leading to high As accumulation in rice grains. The intensification of research to address the problem of As in rice has been seen in the past two decades. It has been realised that appropriate irrigation water management, which acts as a major driver of As chemistry in soil and As uptake and transport in plants, can be an easy and affordable solution. Further, balanced supplement of various nutrient elements like selenium (Se), silicon (Si), sulfur (S), nitrogen (N), iron (Fe) and zinc (Zn) has been found to impart dual benefits in terms of reduced As toxicity as well as enhance the nutritional quality of rice grains. Several other agronomic and biotechnological approaches, processing, and cooking methods of rice were found to have profound impacts on rice As and its speciation from farms to table.

A Comprehensive Review of Arsenic Exposure and Risk from Rice and a Risk Assessment among a Cohort of Adolescents in Kunming, China

Abstract: Inorganic arsenic (iAs) is carcinogenic and highly concentrated in rice. Dietary exposure to iAs is concerning among adolescents due to their developmental stage and iAs's long-latency effects. This paper aimed to assess iAs exposure from rice and related lifetime cancer risks (LCR) among adolescents in Kunming, China. A comprehensive literature review of iAs levels in rice and LCR in humans was also conducted. Average daily consumption of rice (ADC) was estimated from 267 adolescents (15⁻18 years). Rice samples obtained from 6 markets were analyzed for iAs concentration (AC). Estimated daily intake (EDI) of iAs was calculated using ADC, AC, and average body weight (BW). Lifetime Cancer Risk (LCR) was calculated using EDI and U.S. EPA derived iAs oral slope factor. The AC was 0.058 mg/kg and the average BW and ADC were 67.5 kg and 410 g/day for males and 55.5 kg and 337 g/day for females. The EDI and LCR were 3.52 × 10-4 mg/kg-BW/day and 5.28 × 10-4 for both males and females, with LCR 5 times above the U.S. LCR upper limit of 1.0 × 10-4. While the AC was below the Chinese maximum contaminant level of 0.2 mg/kg, study results indicated that Kunming adolescents may be at increased risk for iAs-related cancers.

Modified heavy metal Pollution index (m-HPI) for surface water Quality in river basins, India

Abstract: India is bestowed with huge amount of surface water resources. However, India lacks the quality monitoring of surface water and comprehensive management for sustainable surface water development. A new approach for indexing has been proposed to represent pollution due to heavy metals in surface water. Heavy metal pollution indices (m-HPI) for 60 surface water samples in the peninsular stretch were evaluated during pre-drought, drought and post-drought condition. The Index will be represented by a Positive Index (PI) and a Negative Index (NI), where PI represents the level pollution exceeding the maximum desirable limit and NI reflects the index within the required limit. The PI is assigned as 0 when indicators are present below the detection limit or equal to the maximum required limit. However, the value calculated for NI could be 0 to -1 when the indicators are equal to or less than the suggested maximum desirable limit, and the value could be -1 when the indicators are present below the suggested detection limit. The spatiotemporal variation of water quality pattern was studied by the interpolation maps extracted from ArcGIS. The results are compared with WHO standard to validate the drinking water quality. The calculated indices indicated the suitability of water for domestic and irrigation purposes. The developed indexing system is user friendly, robust, flexible and may evaluate the index considering any water quality standard.