Rajith Perera

@inproceedings{Sakunthala2024,

title = {Statistical Assessment of Toxic Metal Concentrations and its Correlations in Paddy Soils: Comparing the Impact of Chemical and Organic Agricultural Practices in Sri Lanka},

author = {KADD Sakunthala and PLRA Perera and WPRT Perera and JA Liyanage and WAPJ Premaratne},

url = {https://www.researchgate.net/publication/379311099_Statistical_Assessment_of_Toxic_Metal_Concentrations_and_its_Correlations_in_Paddy_Soils_Comparing_the_Impact_of_Chemical_and_Organic_Agricultural_Practices_in_Sri_Lanka



},

year  = {2024},

date = {2024-03-01},

volume = {2},

issue = {2024},

pages = {61},

publisher = {International Research Symposium on Multidisciplinary Approaches in Indigenous Knowledge Systems - IRSIKS },

address = {Gampaha Wickramarachchi University of Indigenous Medicine, Sri Lanka},

organization = {Gampaha Wickramarachchi University of Indigenous Medicine},

abstract = {Background / Originality Evaluating the impact of chemical and organic farming practices on soil toxic metal concentrations is crucial for soil profiling in agroecosystems. Objective This study analyzed heavy metal concentrations within soil samples obtained from paddy fields in the Anamaduwa Divisional Secretariat region. Methodology Paddy soil samples were collected from a chemically fertilized field and an organically cultivated field. Employing a random stratified sampling methodology, twenty composite topsoil specimens were gathered from each paddy field. Toxic heavy metal (Cr, Ni, Pb, As, Cd) concentrations were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The resultant data were further analyzed using the ANOVA test followed by Tukey's pairwise comparison to determine statistically significant variations among the parameters. Furthermore, Pearson correlation analysis was applied. Findings Soil samples from chemically fertilized fields exhibited notably elevated concentrations of Cr (20.09±4.91 mg/kg), Ni (8.58±2.51 mg/kg), Pb (7.15±1.57 mg/kg), and As (0.87±0.17 mg/kg). In contrast, the soil samples from fields that were organically farmed revealed significantly lower mean concentrations of Cr (12.19±3.72 mg/kg), Ni (2.72±1.58 mg/kg), Pb (2.84±1.06 mg/kg), and As (0.49±0.18 mg/kg). The ANOVA test revealed significant differences in pH, conductivity, ammonium nitrogen, potassium, and ash content, and a notable variance in the mean concentrations of Ni, As, and Cr in organic versus chemically fertilized soils (p<0.05) while organic matter and phosphate content showed no significant differences. In the chemically fertilized field, Pearson correlations indicated a strong positive correlation between potassium and heavy metals (Pb, Cr, As, Ni) (r>0.5, p<0.05). Particularly, As showed strong correlation with Cr (r=0.912, p<0.01) and Ni (r=0.862, p<0.01), while the organic field displayed moderate correlations between As and both Cr (r=0.703, p<0.05) and Ni (r=0.779, p<0.01). Cr and Ni showed significant positive correlations (r=0.911, p<0.01) in both fields. Conclusions This suggests that organic farming practices significantly affect soil heavy metal content, leading to reduced levels of these metals. Furthermore, the positive correlations observed between potassium and heavy metals as well as among heavy metals itself emphasize a common origin among them.},

keywords = {Fertilizer, Organic Farming, paddy soil, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Sakunthala2023,

title = {Impact of organic farming practices on toxic metal accumulation in topsoil in paddy areas: A comparative study in Sri Lanka},

author = {KADD Sakunthala and PLRA Perera and WPRT Perera and JA Liyanage and WAPJ Premaratne},

url = {https://www.researchgate.net/publication/377599811_Impact_of_organic_farming_practices_on_toxic_metal_accumulation_in_topsoil_in_paddy_areas_A_comparative_study_in_Sri_Lanka



https://conf.kln.ac.lk/iprc/media/attachments/2024/01/23/abstract-volume-2023.pdf},

year  = {2023},

date = {2023-11-24},

volume = {23},

issue = {2023},

pages = {32},

publisher = {International Postgraduate Research Conference (IPRC)},

address = {Department of Chemistry, Faculty of Science, University of Kelaniya, Sri Lanka},

organization = {University of Kelaniya, Sri Lanka},

abstract = {Given the increasing importance of sustainability in agriculture, this study investigateshow organic farming influences soil toxicity, specifically the accumulation of toxic metalsin paddy fields within the Anamaduwa Divisional Secretariat area. Collections of paddysoil samples were made both from an organically cultivated field and a chemicallyfertilized field. Twenty composite topsoil samples were collected from each paddy fieldaccording to the random sampling method. Soil quality parameters such as soil pH,conductivity, organic matter, total phosphate, potassium, ammonium nitrogen, and ashcontent were analyzed and toxic metal concentrations(Pb, Cd, As, Ni, and Cr) wereanalyzed by Inductively Coupled Plasma–Mass Spectrometry(ICP-MS). Results indicatethe soil collected from paddy areas treated with chemical fertilizers has high average pH,conductivity, total phosphate content, and potassium content. The ammonium nitrogenand ash content were enhanced in the soil collected from organic land and organiccontent fluctuated slightly between the two areas(p>0.05). Soil samples from the fieldusing chemical fertilizers displayed higher average concentrations of Pb(7.15±1.57mg/kg), As(0.87±0.17 mg/kg), Cr(20.09±4.91 mg/kg), Ni(8.58±2.51 mg/kg) compared tothe organically farmed paddy field. The mean concentrations of the Pb, As, Cr, and Ni inthe soil samples of the organically cultivated field were reported as 2.84±1.06 mg/kg,0.49±0.18 mg/kg, 12.19±3.72 mg/kg, 2.72±1.58 mg/kg respectively. Statistical analysisindicates a significant difference in mean heavy metal concentrations(As, Ni, Cr) betweenorganic and chemically fertilized soil samples(p<0.05). The concentration of Cd in thepaddy soil has not been reported in either of the selected paddy areas. In conclusion, thesustained reduction of chemical fertilizer application over a long-term period maycontribute to the decrease in toxic metal contamination observed in the paddy soil withinorganically cultivated areas. This reduction in contamination subsequently mitigates therisk of the transfer of these toxic metals to the paddy root and grain. },

keywords = {Bioaccumulation, Organic Farming, paddy soil, Sri Lanka, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Gunathilka2023,

title = {Toxic metal contamination in food chains via paddy plant; A study in CKDu endemic area in North Western Province, Sri Lanka},

author = {VHNM Gunathilka and WPRT Perera and PLRA Perera and CC Kadigamuwa and JA Liyanage and WAPJ Premaratne},

url = {https://www.researchgate.net/publication/377600053_Toxic_metal_contamination_in_food_chains_via_paddy_plant_A_study_in_CKDu_endemic_area_in_North_Western_Province_Sri_Lanka



https://conf.kln.ac.lk/iprc/media/attachments/2024/01/23/abstract-volume-2023.pdf},

year  = {2023},

date = {2023-11-24},

volume = {23},

number = {22},

issue = {2023},

pages = {31},

publisher = {International Postgraduate Research Conference (IPRC)},

address = {Department of Chemistry, Faculty of Science, University of Kelaniya, Sri Lanka},

organization = {University of Kelaniya, Sri Lanka},

abstract = {This study addresses the urgent need for a comprehensive risk assessment of toxic metal contamination in the food chain via paddy plants in CKDu-affected areas emphasizing the health hazards associated with the transfer of toxic metals from soil to paddy grains and evaluating the health risk of consuming rice through different risk indices. Twenty composite paddy soil samples and twenty paddy plant samples with rice grains in the exact locations were collected from paddy areas in Nikawewa Grama Niladhari division during the Maha growing cycle in 2023. The analysis of Cr, Pb, As, Cd, Ni, and Cu was conducted using inductively coupled plasma-mass spectrometry (ICP-MS). Descriptive statistics revealed the average metal concentrations in rice grains as: Cr(637.42±157.44 µg/Kg), Pb(262 ±62.35 µg/Kg), As(39.29±11.97 µg/Kg), Cd(1836±192 µg/Kg), and Cu(1567 ±466 µg/Kg). Cr, As, and Cu levels in rice grains remained within WHO/FAO and codex limits. However, average Pb and Cd levels surpassed permissible limits (Pb-200 µg/Kg, Cd-50 µg/Kg; WHO). Nevertheless, the Target hazard quotient(THQ) values of Cr and Cd were greater than 1. The estimated Daily Intake(EDI) values of Cr(3.15 µg/Kg/Day) and Cd(9.15 µg/Kg/Day) are higher than Tolerable Daily Intake(TDI) values. The transfer factors(TF) for toxic metals in the soil-root system were determined as follows: Cr-0.069, Pb-0.30, As-0.67, Cd-0.49, Ni-0.10, Cu-0.23. Toxic metal transfer factors in the soil-root system were evaluated, indicating greater uptake by plant roots. When considering a metal transfer from roots to rice grains, Cd had a transfer factor greater than 1, indicating potential accumulation in grains, while Cr exhibited a notable increase in transfer factor compared to the soil-root system. The risk of toxic metal transfer from soil to paddy grains warrants concern due to potential human exposure and related health risks, including Chronic Kidney Disease, from the consumption of contaminated rice grains.},

keywords = {Contamination, Food Chain, Heavy metals, paddy soil, Risk assessment},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{ranasinghe2022risk,

title = {Risk assessment of toxic metal contamination in groundwater and paddy soil; A study in CKDu affected Maradankulama area in Anuradhapura, Sri Lanka},

author = {RAHB Ranasinghe and WAPJ Premaratne and PLRA Perera and WPRT Perera and JA Liyanage},

url = {https://www.researchgate.net/publication/364716756_Risk_assessment_of_toxic_metal_contamination_in_groundwater_and_paddy_soil_A_study_in_CKDu_affected_Maradankulama_area_in_Anuradhapura_Sri_Lanka},

year  = {2022},

date = {2022-10-01},

urldate = {2022-01-01},

booktitle = {International Conference on Applied and Pure Sciences},

publisher = {Faculty of Science, University of Kelaniya Sri Lanka},

organization = {Faculty of Science, University of Kelaniya, Sri Lanka},

abstract = {Chronic Kidney Disease of Unknown Etiology (CKDu) has emerged as a serious public health concern in Sri Lanka. The North Central Region (NCR) has the highest CKDu prevalence in the country, and the disease is more prevalent among farming communities and people who rely on groundwater as their primary source of drinking water. Meanwhile, heavy metal/metalloids exposure and accumulation are recognized as the causative agent of many acute and chronic diseases in certain vulnerable human tissues, including the kidneys. This study assesses the level of contamination of heavy metals/metalloids in drinking water and agricultural soil in a CKDu endemic area in NCR, Sri Lanka. Fifteen groundwater samples collected from wells were analyzed for pH, EC, hardness, heavy metals, and anion concentration using potentiometric, conductometric, titrimetric, inductively coupled plasma mass spectrometric, and ion chromatographic methods, respectively. From six sampling sites in a paddy field, composite soil samples were collected from the surface, and two depths (30 cm and 60 cm). Soil samples were analyzed for pH, EC, organic matter, potassium, phosphate, and heavy metals using potentiometric, conductometric, titrimetric, flame photometric, colorimetric, and inductively coupled plasma mass spectrometric methods respectively. Accordingly, the mean pH of groundwater is 7.25 and this lies within the guideline values. Mean EC is 662.4 µS/cm and mean hardness is 287.0 mg CaCO3/L. Among fifteen samples, four and five water samples have exceeded the health guideline values for EC and hardness, respectively. Metal content varies in the following order, Cd < As < Cr < Cu < Co < Fe < Ni < Mn < Zn. Pb was not detected in any of the water samples and other metals were found in concentrations well below the standard guideline values. Only one sample and three samples exceeded the guideline value for fluoride and nitrite, respectively. Mean pH, EC, organic matter, potassium, and phosphate in paddy soil is 7.57, 101.8 µS/cm, 1.34%, 148.9 mg/kg, and 24.05 mg/kg respectively. Heavy metal content in soil varies in the following order, Cd < As < Pb < Co < Ni < Cu < Zn < Cr < Mn < Fe. Paddy soil from the very bottom showed the highest pH, Pb, Cd, As, Zn, Ni, Mn, Cr, and Fe content while the highest EC, organic matter and potassium content was detected in topsoil. EC, organic matter, and potassium content decreased with the depth of the soil, and the concentration of Pb, As, Zn, Mn, and Fe increased with the depth. This study reveals the dependence of some soil quality parameters on the depth of the soil profile. Monitoring the soil quality is important to minimize the possibility of heavy metal uptake by rice plants. Low heavy metal concentration in groundwater may not have an acute health effect on humans. But long-term chronic exposure to toxic heavy metals together with high EC, hardness, and fluoride would be a reason to trigger the prevalence of CKDu in Maradankulama area.},

keywords = {CKDu, Drinking water, paddy soil, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}