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{kumari2022investigation,

title = {Investigation of toxic metals contamination status in red raw rice (Bg 350) grown in North Central province in Sri Lanka},

author = {MKJK Kumari and WAPJ Premaratne and PLRA Perera and WPRT Perera and JA Liyanage},

url = {https://www.researchgate.net/publication/367091781_Investigation_of_toxic_metals_contamination_status_in_red_raw_rice_Bg_350_grown_in_North_Central_Province_in_Sri_Lanka},

year  = {2022},

date = {2022-12-01},

urldate = {2022-01-01},

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

pages = {87},

publisher = {Faculty of Graduate Studies, University of Kelaniya Sri Lanka},

abstract = {Red raw rice consumption is high due to its nutritional properties. The chemical components of food

are correlated with their ability to sustain better human health. Rice is the staple food of Sri Lanka.

Although it is a good source of nutrients in a diet, its consumption can also lead to exposure to toxic

metals due to environmental pollution. Rice is grown extensively in the North Central Province (NCP)

where the prevalence of chronic kidney disease of unknown origin (CKDu) is high. This study was

aimed to determine the toxic metal content such as Arsenic (As), Cadmium (Cd), and Lead (Pb) in

domestically grown red raw rice in NCP and assess the risk of these values to human health. A total of

35 samples Of red raw rice were obtained from farmers in NCP during Yala growing cycle in 2021 based

on the eight sampling sites. As, Cd and Pb levels were analyzed by Inductively Coupled Plasma-Mass

Spectrometry (l •Ille potential health risk was estimated by Estimated Daily Intake (EDI). The mean Pb levels

in red raw rice were higher than the FAO/WHO allowable limits (Pb-200 gg/kg) in all the selected areas

except the Rambewa area. The highest mean pb concentration was recorded in the Horowpathana area

as 429.93±100.93 pg/kg. As and Cd values were within FAO/WHO allowable limits (As-200 pg/kg, Cd-

400 gg/kg). The highest mean value of as was recorded in the Medirigiriya area, and it was 97.72±18.19

gg/kg. The highest Cd level was recorded in the Horowpathana area as 60.70±24.39 gg/kg The

estimated daily intake (EDI) values are also significantly lower than the Tolerable Daily Intake (TDI)

(Pb-250 gg/day, Cd-62 gg/day. As-3 gg/day). Dietary exposure is the most common route through

which these toxic metals enter the human body. Long term consumption of red raw rice causes to

accumulate the toxic metals in body tissues and generates adverse health effects of residents in selected

CKDu prevalent areas in NCP. It is suggested that further studies are needed to get a more

comprehensive idea on the public health concerns of toxic metals due to red raw rice consumption in

Sri Lanka.},

keywords = {CKDu, Contamination, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Kumari2022,

title = {Investigation of Toxic Metals in Parboiled Rice Grown in Anuradhapura District},

author = {MKJK Kumari and WAPJ Premaratne and PLRA Perera and WPRT Perera and JA Liyanage},

url = {https://www.researchgate.net/publication/366701095_Investigation_of_Toxic_Metals_in_Parboiled_Rice_Grown_in_Anuradhapura_District},

year  = {2022},

date = {2022-11-10},

urldate = {2022-11-10},

booktitle = {International Conference on Innovation and Emerging Technologies (ICIET)},

volume = {2022},

pages = {122},

address = {Sri Lanka},

organization = {University of Sri Jayewardenepura},

abstract = {Parboiling is the most common processing method used in the rice industry, which affects on quality of rice. This study was designed to determine the levels of toxic metals such as arsenic (As), cadmium (Cd), and lead (Pb) in rice grown in Anuradhapura district (AD) which was identified as one of the high chronic kidney diseases of unknown etiology (CKDu) prevalent areas in North Central province, Sri Lanka. A total of 70 parboiled rice samples were obtained from six areas in AD. The levels of As, Cd, and Pb were determined using inductively coupled plasma-mass spectrometry (ICP-MS) followed by microwave acid digestion. Except for Pb, levels of As, and Cd in all rice samples were lower than the maximum permissible limits (As-200 µg/kg and Cd-400 µg/kg) given by the FAO/WHO. The mean Pb level of rice samples collected from some areas exceeded the FAO/WHO allowable limits (Pb-200 µg/kg). Rambewa area has reported 1122 µg/kg mean Pb content in the rice samples. The highest mean value for As was recorded as 95 µg/kg in Kahatagasdigiliya area. The highest Cd level was recorded in Rambewa area as 65 µg/kg. The highest estimated weekly Pb intake was recorded as 39 µg/kg body weight. The highest estimated weekly As and Cd intakes were recorded as 3 µg/kg body weight and 2 µg/kg body weight. The estimated weekly metal intake values are also significantly lower than the provisional tolerable weekly intake (PTWI) (Pb-5 µg/kg body weight, Cd-7 µg/kg body weight, and As-15µg/kg body weight) except for Pb in Rambewa area. Contamination of the Pb, As, and Cd in rice grains may occur via transfer from the paddy soil. Therefore, the parboiled rice may contribute to generating adverse health risks via metal toxicity of the residents in selected CKDu prevalent areas.},

keywords = {CKDu, Parbolic Rice, Toxic Metals},

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}

}

@inproceedings{mkjk2022bioaccumulation,

title = {Bioaccumulation of toxic metals in Oryza sativa grown in North Central Province in Sri Lanka},

author = {MKJK Kumari and WAPJ Premaratne and PLRA Perera and WPRT Perera and JA Liyanage},

url = {https://www.researchgate.net/publication/361999369_Bioaccumulation_of_toxic_metals_in_Oryza_sativa_grown_in_North_Central_Province_in_Sri_Lanka},

year  = {2022},

date = {2022-06-01},

urldate = {2022-01-01},

booktitle = {International Symposium on Agriculture and Environment(ISAE)},

volume = {2022},

pages = {32},

publisher = {University of Ruhuna, Sri Lanka},

abstract = {This study was carried out to assess the levels of heavy metals such as Arsenic (As), Cadmium (Cd), and Lead (Pb) in domestically grown rice sold in North Central Province (NCP) which is identified as a high CKDu prevalent area in Sri Lanka. Based on eight paddy areas, thirty Oryza sativa composite samples were collected in each selected Divisional Secretariat (DS) area in NCP. Samples were subjected to microwave digestion process and As, Cd and Pb analysis were carried out by the ICP-MS. The mean Pb levels in domestically grown rice were significantly higher than the FAO/WHO allowable limits (Pb-200 µg/kg) in most of the DS areas. Among selected DS areas, the Padaviya DS area has highlighted reporting 2815 µg/kg mean Pb content in the rice samples. However, none of the mean values of As and Cd in rice samples in selected areas have exceeded the FAO/WHO allowable limits (As-200 µg/kg, Cd-400 µg/kg). The Highest Cd contamination was reported in Higurakgoda and Padaviya DS areas and the values were 106.69 µg/kg, 105.69 µg/kg, respectively. The highest mean value of as was reported in the Kebithigollewa DS area and it was 49.75 µg/kg. The values of estimated daily intake (EDI) of the analyzed metals were also very far below than the Tolerable Daily Intake (TDI) (Pb-250 µg/day, Cd-62 µg/day, As-3 µg/day). Owing to high Pb content in domestically grown rice samples in selected areas, long term consumption of rice causes to accumulate the Pb in body tissues and generates a health risk of residents in selected CKDu affected areas in NCP.},

keywords = {CKDu, Contamination, Parbolic Rice, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{perera2021risk,

title = {Risk Assessment of Bioaccumulation of Toxic Metals in Rice Grains (Oryza sativa) in a CKDu Endemic Area; A Study in Mihintale Division, Sri Lanka},

author = {PLRA Perera and WPRT Perera and JA Liyanage},

url = {https://www.researchgate.net/publication/354193460_Risk_assessment_of_bioaccumulation_of_toxic_metals_in_rice_grains_Oryza_sativa_in_a_CKDu_endemic_area_A_study_in_Mihintale_division_Sri_Lanka},

year  = {2021},

date = {2021-08-01},

urldate = {2021-01-01},

booktitle = {Research Symposium of the Faculty of Allied Health Sciences - RuFARS},

publisher = {Faculty of Allied Health Sciences, University of Ruhuna, Galle, Sri Lanka},

abstract = {Background: Chronic Kidney Disease of unknown etiology (CKDu) is a heterogeneous disorder affecting kidney structure and its functions. CKDu has rapidly spread throughout Sri Lanka in the past two decades and has become predominant in the North Central Region. Food or water borne diseases are one of the key issues in food safety assurance in Sri Lanka. Pesticides and heavy metals play an important role in modern agriculture and food safety. Objective: To evaluate the toxic metal contamination status in the polished rice samples (BG 300) grown in the Maradankulama area. Methods: Maradankulama GN Division was selected based on the available information on medical/hospital records, which has the highest number of CKDu patients in the Mihintale Division as the sampling area. A survey protocol was also developed. Thirty polished rice samples (BG 300) were collected from the households subject to three paddy areas in the Maradankulama GN area according to the random stratified sampling method and heavy metal concentrations of rice samples (Chromium, Lead, Arsenic and Cadmium) were analyzed by ICP-MS. Results: The male CKDu patients were higher than females (Male, 57.15%; Female, 42.85%). All the CKDu patients subjected to the survey in the area belong to the farming community within the age group of 60-70 years. In Maradankulama Cr(7.268±0.046), Pb(1.923±0.209), As(0.064±0.009) and Cd(0.026±0.003) were detected in mg/kg levels. Among the analyzed metals in the rice samples, mean Cr and Pb contents have exceeded the maximum permissible level (MPL) according to the Codex Alimentarius commission guidelines. Conclusion: Arsenic and Cadmium contents in the rice samples were well below the Codex standard. However, rice samples have been contaminated with some nephrotoxic metals such as Chromium and Lead. Hence, long term exposure to the toxic metals may generate a risk for kidney damage in people.},

keywords = {CKDu, CODEX, Contamination, Oryza sativa, Toxic Metals},

pubstate = {published},

tppubtype = {inproceedings}

}