# Metal and Pesticide Assessments of Imported and Locally Cultivated Rice (_Oryza sativa_) in Senegal
###### Abstract  
Identifying heavy metal and pesticide contaminants is an essential step in assessing the health indicators of rice cultivation and consumption in Africa. Information on the contaminant levels of the imported and cultivated rice consumed in Senegal seems lacking. In this study, we assessed heavy metals, pesticides, ash, and protein in rice using rice samples from India, Thailand, South America, Vietnam, and China. Arsenic, Pb, Cd, Ni, Cu, Mo, Co, Cr, and Al are usually found in the soils used for rice cultivation in northern Senegal. While the heavy metal levels measured in soils were above the threshold limit, only Pb, Cd, and Al were found in cultivated rice. In all the analyzed rice samples from each country, there were certain amounts of Pb, As Al, and Cd. The concentration ranges in the six countries were as follows: 0.635-1.165 mg kg\({}^{-1}\) for Pb, 0.047-0.438 mg kg\({}^{-1}\) for As, 2.22-95.54 mg kg\({}^{-1}\) for Al, and 0.002-0.082 mg kg\({}^{-1}\) for Cd. The protein content in cultivated rice in Senegal was 7.31 mg kg\({}^{-1}\), while the average from the imported rice ranged between 6.42% and 7.32%. The humidity levels in imported rice ranged between 11.12% and 12.95%. The fat content for the rice from six countries ranged between 0.22% and 0.67%, and the ash content ranged between 0.23% and 0.48%. These results allowed for the determination of the carbohydrate concentration, which varied between 79.18% and 80.82%. Indeed, freshly harvested rice grains typically contain around 80% carbohydrates. We noticed the presence of pesticides in all rice samples. The levels of three pesticides (total Pyrethrin, Bensulfuron-methyl, Propanyl, and 2,4D) were found to be beyond their maximum residue limits (MRLs) from the Codex Alimentarius, whereas deltamethrin was found to be below its MRL. This study indicates the presence of heavy metals carcinogenic to humans (Al, As, Cd, and Pb). Additionally, this study reveals the presence of deltamethrin, which is classified as probably carcinogenic to humans (Group 1), and 2,4-dichlorophenoxyacyacetic acid, which is classified as possibly carcinogenic to humans (Group 2B). t 20 January 202425 February 202425 February 202426 February 202(Group 2A), possibly carcinogenic to humans (Group 2B), and not classifiable as to their carcinogenicity to humans (Group 3). Lead (Pb) is classified as probably carcinogenic to humans (group 2A) and Cadmium (Cd), aluminum (Al), and arsenic (As) are classified as carcinogenic to humans (group 1). Deltamethrin is probably carcinogenic to humans (group 1) and 2,4-dichlorophenoxyacetic acid is possibly carcinogenic to humans (group 2B). Senegal is one of the West African countries where rice constitutes its main cereal food source. The average consumption of milled rice per capita per year is approximately 75 kg, while it is around 52 kg in Asia [8]. In 2009, rice consumption amounted to 1.1 million tonnes; only 45% of what was consumed was produced locally, and 55% was imported from India, Thailand, and Vietnam. On average, the national rice production covers around 20 and not more than 30% of the country's rice demand [9]. The Senegalese government has prioritized rice self-sufficiency and embarked on massive investments to enhance productivity within Africa [9]. The total production of local paddy rice was estimated at one million tonnes in 2018 compared with 559 tonnes in 2015, which demonstrates an increase of 102% in the past five years. Rice is the main food product consumed in Senegal and has been an important source of heavy metals through absorption effects [10]. Although numerous studies have shown the heavy metal contamination of rice in different countries [11], information is lacking regarding heavy metal contaminants in the rice consumed in Africa [12]. Being exposed to heavy metals is a human health concern. Effective agricultural soil management reduces soil contaminations and heavy metal accumulations in plants like rice [13; 14].