# Sensory Perception Systems and Machine Learning Methods for Pesticide Detection in Fruits
## 1 Introduction  
Agriculture is the pillar of human and economic development worldwide [1]. Throughout history, agriculture has been a primary source of food supply for humanity since all countries depend on it for their food. Therefore, as the population increases, the demand for nonwishment continues to grow exponentially, which generates a request for land to develop food products and thus meet the food needs worldwide [2, 3]. The above allows for us to accomplish the second sustainable development goal (SGD2), which consists of ending hunger, achieving food security and improving nutrition, and promoting sustainable agriculture [4, 5, 6]. According to Food and Agriculture Organization of the United Nations (FAO) data, global food production must increase by 70% to feed the world population by 2050 [7]. Nowadays, rising crop production often requires external inputs, such as pesticides, which have been widely applied to protect foods against pests to improve their quality production and increase crop efficiency [8]. According to estimates by FAO, approximately 45% of annual food production is lost due to pest infestation, threatening food security and causing economic losses due to the resources used to produce these foods (i.e., water, land, energy, labor, and capital) [9, 10]. Therefore, effective pest management through a wide range of pesticides is required to confront them and enhance crop production, as mentioned earlier [11]. Currently, in the world, three billion kilograms of pesticides are consumed yearly, of which 47.5% are herbicides, 29.5% insecticides, 17.5% fungicides, and 5.5% other pesticides [12; 13]. However, only 1% of total pesticides are used effectively to control pests on target plants [14]. Additionally, 99% of the pesticides used are lost through spray drift, off-target deposition, runoff, and photodegradation, resulting in pesticides entering the environment, where they negatively affect the environment. Soil, water, and vegetation can remain in crops and finally enter the food chain, posing a threat to humans [15; 16]. Human beings are exposed to pesticides directly in the workplace or indirectly through environmental media. When handling and using pesticides to irrigate and fumigate crops, farmers are in direct contact with them through inhalation, ingestion, and dermal contact, which causes damage to the skin, eyes, mouth, and respiratory tract [17; 18], having to deal with reactions such as headache, irritation, vomiting, sneezing, skin rashes, dizziness, difficulty breathing, neurotoxicity, and chronic diseases such as cancer, with breast cancer being the most common of all and it is associated with organophosphates (malathion and parathion) that affect cell growth and proliferation and incidences of death [19]. It is essential to highlight that the intensity of the effects of pesticides on humans depends on the exposure time, toxicity, and concentration [15]. According to the World Health Organization (WHO), cases of pesticide poisoning have been identified, generating an actual public health problem in the world, especially in developing countries, where the most significant number of cases occur [20; 21]. In Colombia, according to the National Institute of Health and the National Public Health Surveillance System (SIVIGILA), in 2020, 17,270 poisonings were reported, mainly due to psychoactive substances, medications, and, thirdly, pesticides, where 37.7% occurred accidentally, and 26.7% with psychoactive intentionally. Colombia also has no exact data on mortality due to pesticide poisoning [22]. Another way of exposure to pesticides is indirectly through environmental media, such as air, water, soil, and the food chain, which can be contaminated with pesticides [18; 23]. Undesirable substances such as pesticides in foods are a critical indicator of food quality and safety [14]. We know that fruits and vegetables are vital elements of a healthy human diet due to their high proportion of fiber, vitamins, and minerals.