The cashew tree (Anacardium occidentale L.) is a tree native to tropical regions [1] . It is a plant species of significant economic importance worldwide, due to its natural products: the cashew nut (botanically, the fruit) and the pseudofruit (which is actually an extended, fleshy stalk), the cashew apple. Since 2015, Côte d’Ivoire has become the world’s biggest producer and exporter of raw cashew nuts. And since then, production volumes have increased considerably year after year, reaching a record production of 900,000 tonnes in the recent 2018-2019 season, which represents almost 24% of world production [2] [3] . Cashew nut cultivation is mainly concentrated in three major regions of the country, namely the Poro, Hambol and Gontougo regions, where it has now become the main cash crop to diversify farmers’ incomes [4] .

However, because of pests [5] , large orchard areas and insufficient labour, producers are increasingly resorting to phytosanitary treatments to take care of their different cashew plantations [6] . According to [7] , the majority of phytosanitary interventions in cashew cultivation in the main production areas are to control weeds and plant pathogens in the crops. However, despite the efficacy of pesticides on pests and their positive effect on the yield increase, their bad use is not without consequences for the health of farmers, consumers or for the environment [8] [9] . At the level of farmers, acute or chronic pesticide intoxications are increasing very considerably worldwide [10] [11] [12] . The situation is most dramatic in African countries, which use only 10% of the world’s pesticides but have over 75% of fatal intoxications [13] [14] . One of the main reasons for this dramatic situation is related to the poor conditions of pesticide use by African farmers [15] [16] [17] . Moreover, in Africa, data on pesticide poisoning cases are very partial. Most of them come from the Pesticide Action Network (PAN). The data published in 2011 for countries such as South Africa, Senegal, Benin and Mali clearly show that the health consequences of the manipulation of pesticides constitute a real health problem in developing countries [18] . Since then, the links between pesticide use in agriculture in developing countries and producers’ health problems have been increasingly studied [16] [17] [19] . And the results are alarming. Indeed, the results show that the exposure levels of producers under real working conditions are extremely high following their phytosanitary practices.

Unfortunately in Côte d’Ivoire, in most agricultural tasks, data on pesticide exposures of producers in real working conditions are scarce, and no agency is responsible for producing them. However, without sufficient knowledge on pesticide exposures in real working conditions, there is no sound risk assessment, either before or after product approval [19] [20] . These unknowns hinder the generalisation of measures to reduce exposures which pose a risk to the health of agricultural workers [20] . Thus, farmers continue to be dangerously exposed, in unknown proportions, in terms of the number of exposed workers and the quantity of exposure. According to the mapping of cashew nut production areas, cashew nut producers represent more than almost all Ivorian farmers [2] [4] [6] . The assessment of health risks for these producers, and consequently the adaptation of appropriate protective measures, is therefore necessary to preserve the health of farmers.

It is in this context that this study was conducted in the three major cashew production areas of Côte d’Ivoire. The objective of this work was not only to better characterize the phytosanitary practices of producers, but also to assess the potential risk of phytosanitary practices on their health and the possible exposures to pesticides in real conditions of use.

In our previous study focused on study of pesticides use conditions in cashew production in Côte d’Ivoire, we revealed veritable disparities in pesticides use with poor applicators protection in the three main of cashew nuts production areas namely Bondoukou, Mankono and Dabakala [7] . Several cases of acute intoxication (headache, nausea, etc.) have been reported in 37.6% of producers who applied pesticides twice in every agricultural year for 2 to 4 h and in some cases (26%) within 1 and 4 pm without efficient protection [7] . The present

RD: Recommended dose; AOEL: Acceptable Operator Exposure Level; LD₅₀: is the amount of a single-dose administered at one time that causes the death of 50% (half) of a group of test animals.; (-) = not available; mg/kg bw/day: milligrams per kilogram of body weight per day.

RD: Recommended dose; AOEL: Acceptable Operator Exposure Level; LD₅₀: is the amount of a single-dose administered at one time that causes the death of 50% (half) of a group of test animals.; (-) = not available; mg/kg bw/day: milligrams per kilogram of body weight per day.

study, by quantitative analysis of toxicological risk linked to pesticides used in cashew production in Côte d’Ivoire provided data in order to a better understanding or assessment the real exposure levels and consequently the impact of pesticides on the health of farmers. Two models of predictive of toxicological impact of pesticides namely the Quebec-IRPeQ pesticides risk indicator and the UK Predictive Operator Exposure Model (UK-POEM) were used to follow 76 applicators about their pesticide’s practices. Theses predictive models were efficient, reliable and largely used in several studies [16] [17] [23] [24] [25] [26] . In parallel, toxicological characteristics of pesticides ingredients or active substances have been collected such as dermal LD50, AOEL and toxicological properties data according to CLP system.

As results, critical exposure of applicators by pesticides has been found at Mankono and Dabakala areas. Indeed, the highest predictive exposure values during mixing/loading and spraying operations were observed in these regions Mankono with values ranged from 7.5079 (glyphosate) to 17.5529 (2.4 D amine salt) mg/kg bw/day without PPE and from 3.08 (glyphosate) to 8.5941 (2.4 D amine salt) mg/kg bw/day with PPE worn. Despite the decreasing of exposure level when applicators were protected, it remained high. Similary, such findings were observed with some incecticides namely acetamiprid, cypermethrin, imidacloprid and metalaxyl. Predictive exposure of applicators was obtained on the basis of only 10% of dermal absorption from product, the minimal of dermal absorption of pesticide ingredients [26] despite the high relative values of their octanol-water partition coefficient (Kow). The values of logKow of active substances identified in our study were ranged from −3.2 (glyphosate) to 7 (lambdacyhalothrine). However, the lack of safe or protective equipment enhanced to pesticides potential exposure level for cashew producers. For example, with the insecticide Lambda-cyhalothrin, the potential exposure in cashew producers without PPE increased until at 1000%. Similarly, without protection for applicators, the exposure level of the fungicide mancozeb increased namely 21 times higher (0.752 mg/kg bw/day) than the acceptable threshold limit which is 0.035 mg/kg bw/day. Thus, it is very imperious for cashew farmers in Côte d’Ivoire to use pesticides in safe conditions. Indeed, our previous study had been revealed that only 0.4% of producer applicators were eligible for complete protection [7] . It is also imperious for Ivorian regulatory organism to reconsider the recommended doses of pesticides which remained very high despite the protection of farmers. For example, glyphosate and 1431.6 presented a percentage of AOL of 1431.6 and 6564.5 respectively despite the recommended doses and the complete protection (PPE) of farmers. Those findings supported the previous studies revealing herbicide glyphosate was toxic for the farmers [27] [28] . The insecticides acetamiprid, cypermethrin and imidacloprid were also concerned by similar situation. That supported findings previously reported in Niger and Burkina Faso for tomato producers [16] [17] . It is also important to take a look at the duration of applicators exposure which was long namely ranged from 2 to 6 hours by day during several days according to plantations size, for example, 7 days for a plantation of 10 hectars [7] . However, pesticides exposure could be enhanced in cashew farmers since they used often pesticides packages as gourds and kitchen utensils such as containing salt, milk or oil [7] . Such situation could conduce to a long exposure and consequently chronic intoxication in farmers and their families. Concerning the predictive impact on farmers health, our findings demonstrated by the high TRI (Toxicological Risk Index), the real probability for some actives substances to cause acute toxicity and chronic toxicity such as cancer and reproduction toxicity as previously reported [9] [29] [30] . These actives substances namely Mancozeb, Lambda-cyhalothrin mancozeb Profenofos and herbicide 2,4-D must be removed in the list of regsitered pesticides in Côte d’Ivoire or in default, Ivorian regulatory organism must be reinforce their safety requirements. Those requirements should be concerned the trade formulations of pesticides used in cashew production in Côte d’Ivoire. Indeed, despite the same composition of active substances, some formulations have been found more hazardous. Thus, while the formulation Lambdacal P 318 EC presented the highest risk to human health with an index (HRI) of 1189.81, the one named Decis 12.5 EC presented the lowest risk of impact on human health with an HRI of 56.7. Similarly, herbicides (Glyphader®, Kalach® and Ladaba®) generally presented low levels of HRI even though a high HRI of 432.98 was recorded for the formulations Herbextra®.

In conclusion, the present study on the quantitative human exposure of pesticides in cashew production in Côte d’Ivoire revealed that the use of pesticides dramatically poses some concerns in Mankono and Dabakala. The recommended doses of actives substances should be reconsidered following by more exigences on pesticides applicators protection. In addition, there is a lack of culture of risk prevention in the production of cashew nuts in Côte d’Ivoire. Intensive training on safe pesticide use should be performed for producers of cashew nuts in Côte d’Ivoire.

Yao Stéphane KOFFI: Methodology, Supervision, Software, Formal Analysis, Resources, Data Retention and Analyses, Research and Acquisition of funding. James Halbin KOUADIO: Project Administration, Conceptualization, Methodology, Resources, Data Retention, Supervision, Writing Original Project, Research and Acquisition of funding. Diakiali SON: Contributed to the analysis of the data.

Institutional Review Board Statement: Ethical review and approval were waived for this first part of the study in lieu of verbal consent of producers. For this study, we used an anonymous questionnaire to ensure the confidentiality of the information collected. However, a dossier has been prepared for the ethics committee for further work. Indeed, we envisage testing biomarkers of exposure and screening pathologies with a medical team.

This first part of the study was realized with our personal funds.

The authors declare no conflicts of interest regarding the publication of this paper.

Koffi, Y.S., Kouadio, J.H. and Son, D. (2022) Pesticide Exposure Levels and Risk Assessment in Operators Involved in the Cashew Production in Côte d’Ivoire. Agricultural Sciences, 13, 86-104. https://doi.org/10.4236/as.2022.131008