Insights on the Use of Pesticides in Two Main Food-Supplier Coastal Valleys of Lima City, Peru

: The food security of Lima—Peru’s capital city, which shelters over 30% of the total country’s population—depends on the food production of its nearest agricultural areas, the Chancay-Huaral and Chill ó n valleys, wherein agrochemicals are widely used. This study primarily aimed to determine the characteristics of pesticide use in these two valleys, located 83 and 30 km north of Lima City, respectively. A second aim was to assess whether proximity to Lima provides access to technical assistance regarding agricultural activities. A questionnaire-based survey assessing socioeconomic aspects, occupational exposure, and agrochemical-related knowledge was conducted on a sample of 102 participants (farmers and fieldworkers). The results revealed that the average age for starting to handle pesticides was 15 years, while life-long occupational-exposure averaged 30 years. Most pesticides used were organophosphates and carbamates. Personal protective equipment was not used and, therefore, dermal exposure and inhalation were major routes of intoxication. Despite their proximity to Lima, both valleys lack an official agronomic advisory agency, and this void has been occupied by agrochemical manufacturing companies and trading houses focused on increasing their sales. Based on the results, it is urgent to implement an official technical advisory service and a capacity-building program on pesticide use in Peru, as well as the implementation of measures for improved control, trade, and storage of pesticides. Simultaneously, a permanent epidemiological surveillance at the country level is needed to improve public health and to contribute to achieving the Sustainable Development Goals of the United Nations’ 2030 Agenda in Peru.


Introduction
Located in the Andean region in South America, Peru is one of the five most biodiverse countries in the world.It is home to the Amazon forest, the world's largest rainforest, which represents 60.3% of the Peruvian territory.Peru's coastal region is a desert bounded by the Pacific Ocean and represents 11.6% of Peru's territory, while the mountain area, i.e., the Andes highlands, represents 28.1% of Peru's territory [1,2].According to the IV National Agrarian Census of Peru, 30.1% of the total area of the Peruvian territory is dedicated to agriculture, from which, 57.5% is located in mountain areas, 31.1% is located in rainforests, and 11.5% in coastal areas [3].The agricultural sector contributes to approximately 7% of the national gross domestic product (GDP) of Peru [4].
Lima City, the capital of Peru, is the second largest city in South America with a population of above 10.2 million inhabitants, corresponding to 30.2% of the total population of Peru [5,6].The city of Lima initially developed in the Peruvian coastal area, on lands deposited by the Rímac River, and gradually expanded into two nearby valleys, the Chillón (northern) and Lurín (southern) valleys.With continuous urban growth, agriculture disappeared from the Rímac valley and was drastically reduced in the Chillón and Lurín valleys.Currently, the food supply and food security of Peru's capital city largely depends on the agricultural products from the Chancay-Huaral valley located 83 km north of Lima City and, complementarily, the Chillón and Lurin valleys and other agricultural areas of the country.
In Peru, small-scale farming (<5 ha surface area) constitutes 80.5% of the total agricultural units in the country and supplies most food markets in Peru [7].Consequently, small-scale farmers (SSFs) are the strategic actors in food supply chains and play a key role in the national food security [7][8][9][10][11][12].However, despite their central importance in food production, up to the year 2022 only 3.8% of SSFs have received some technical assistance or advice from official agricultural agencies [7].Furthermore, SSFs lack capital and financial resources to procure the relevant training and technical information for improving agricultural practices and enhancing their agronomic management skills, particularly in crop protection aspects such as pest control and reducing the environmental and public health hazards related to pesticide use.The absence of official agro-advisory services has allowed sales agents from agrochemical manufacturing companies and agrochemical trading houses to assume this role.Naturally, these agents are focused on maximizing the sales of their agro-related products rather than providing sound technical assistance to farmers [11].
The most commonly used pesticides in Peruvian agriculture are organophosphate and carbamate compounds [13].Remnants of persistent organic pollutants (POPs) are still used, mainly in the mountain areas, despite the ban on POPs (organochlorines) imposed by the Servicio Nacional de Sanidad Agraria (National Service of Agricultural Sanitation of Peru-SENASA) in 2006 [13][14][15].Unfortunately, there is little statistical information regarding the amount and value of pesticides used in agriculture in Peru.The available information based on data from the Ministry of Agriculture of Peru (MINAG), revealed that the amount of formulated pesticides imported annually displayed a sudden decrease from 2959 to 1727 metric tons between 1981 and 1985 [16].From 2012 to 2016, a sudden increase occurred in the annual import of pesticides, increasing from 19,209 to 26,061 metric tons per year, which represented an increase of 26.3% in the amount of pesticides imported in just one lustrum [17].Information regarding the value of pesticides imports is available as the CIF price-the actual value of goods (pesticides) delivered at the frontier (ports, harbors) of the importing country, i.e., Peru.As expected, the CIF value of pesticide imports showed a trend similar to the trend of their imported amount, with a sudden increase from USD 165,573 to 199,559 million from 2012 to 2016 [17].Recent information based on official data from the National Customes Agency (Aduanas) of Peru and the Superintendencia Nacional de Administración Tributaria of Peru (National Superintendency of Tax Administration-SUNAT) revealed that the increasing trend of imported pesticides has been maintained in the most recent years with the CIF value of imported pesticides growing from USD 260 million in 2020 [18] to USD 310 million in 2022 [19].Although these records might be incomplete, they clearly indicate an intensive usage of pesticides in the agriculture of Peru in recent years, as 69.9% of SSFs commonly used these agrochemical products in food production [7].
In addition, according to the Ministry of Health of Peru (Ministerio de Salud-MINSA), since 2002, there has been an increasing incidence of poisoning by pesticides in the country.The causes for this have been attributed to the improper handling of agrochemicals, use of unsafe methods in their application, inadequate crop management practices, and careless disposal of pesticide-contaminated packaging, among other factors [13,20].
In recent decades, several reports pointed out to human health detriment around the world due to pesticide exposure [21][22][23][24][25][26].This seems to be part of a global issue with pesticides [27,28].Exposure to pesticides can lead to short-and long-term health issues, but the clinical symptoms are heterogenous and depend on the specific pesticide class.In general, short-term effects require the absorption of higher doses and manifest as acute intoxication, in which case, the pesticide use and the appearance of clinical symptoms are close in time and this relationship can be easily recognized by the fieldworker.For example, acute intoxication with organophosphates blocks the enzyme acetylcholinesterase, provoking a cholinergic crisis with symptoms such as nausea, diarrhea, and respiratory distress, the latter potentially leading to death after high exposure.However, more problematic is a prolonged, low-level pesticide exposure, whose detrimental long-term health risks are asymptomatic at the beginning and, hence, difficult to identify.For example, chronic exposure to the widely used organophosphates and carbamates has been associated with an elevated risk for non-Hodgkin lymphoma, a type of leukemia, whereas for other classes of pesticides, such as organochlorines and pyrethroids, an increase regarding this pathology could not be demonstrated [29].In Peru, malformations of the mouth and palate, cardiovascular system, extremities, genitourinary system, central nervous system, and others have been observed and reported for children whose mothers manipulated pesticides or lived by pesticide-fumigated fields during pregnancy [30].The high exposure to pesticides in Peru has been evidenced through analyses of hair samples from people living in the Central Andean highlands, where, on average, human hairs were contaminated with 12 pesticides in concentration levels approximately 10 times higher than the pesticide concentrations in hair samples from people living in rural areas of France.This contamination of human hair with pesticides reported in Peru highlighted the exposure to pesticides in agricultural fields but also alerted us to the consumption of foods contaminated with pesticide residues [31].Such impacts of agrochemicals and their residues on human and environmental health requires attention as they may collide with several Sustainable Development Goals, especially with the third one, i.e., the right to good health and well-being [32][33][34].The application method also influences the degree of pesticide exposure and their related health risks [35].Although relative secure techniques such as foliar and drench application as well as soil injection exist, spraying remains by far the most used method in developing countries, including Peru, and can lead to pesticide uptake via all three routes, i.e., via oral, inhalation, and dermal routes.It has been demonstrated that dermal exposure is the usual and most efficient uptake route for professional high-risk groups directly exposed to pesticides, such as fieldworkers.Importantly, not only the pesticide application itself (crop spraying), but also the necessary mixing and handling procedures must be considered because they are equally able to provoke excessive dermal exposure levels [36].
In the absence of accurate statistics on pesticide use, the absence of close monitoring of pesticide usage and the lack of measurements of pesticide residues in foods and the environment, the direct contact with farmers and rural workers was used as a method for gathering insights on the exposure to agrochemicals.
The present study was designed to identify exposure factors in the use of pesticides in Peru.The Chancay-Huaral and Chillón valleys were selected as a representative sample of the agricultural areas of the whole country.A secondary aim of this study was to determine whether the proximity of the agricultural areas to Lima City has facilitated better access to advisory services (technical information, training, health control, etc.) for farmers compared to other agricultural regions of the country.

Study Areas
This study was conducted during the austral spring of 2011 in two coastal valleys of Peru, both located north of Lima City:  The agricultural importance of both valleys started from the pre-Inca period (about 10,000 years BC) and continued during the Hispanic colonization.At present, the The agricultural importance of both valleys started from the pre-Inca period (about 10,000 years BC) and continued during the Hispanic colonization.At present, the Chancay-Huaral valley excels in agricultural production (potato, garlic, maize, cotton, vegetables, strawberries, and other fruits, mainly citrus fruits such as tangerines and oranges, but also avocadoes, peaches, and mangos, among others) destined for local markets (Lima City) and external markets (mainly the United States, United Kingdom, and European Union).Contrasting with this, the production from Chillón valley (mainly vegetables, maize, cotton, and potato) are destined almost entirely for the local market, i.e., Lima City.

Data Collection
An observational transversal descriptive study, supported by questionnaire-based interviews, was carried out in the Chancay-Huaral and Chillón valleys and comprised farmers (landowners) and fieldworkers (pesticide applicators).Before the data collection, all participants were informed about the objectives of the study and they provided informed consent for their voluntary participation.The survey was conducted through visits to the agricultural fields in the early morning (from 7 to 10 a.m.) to interview the participants during their activities.This timeframe was selected based on the knowledge that in the central coastal area in early morning, mostly between 6 and 11 h, the weather is neither too hot nor windy, thus allowing 'good' application conditions, as stated by the farmers.Indeed, in Chillón valley, in the winter season, a dense fog extends until 10 a.m., so the time for application is generally extended to midday.
Data collection was carried out using a questionnaire that was previously reviewed and approved by the Ethics Committee of the Universidad Nacional Agraria La Molina (La Molina National Agrarian University-UNALM, Peru).The questionnaire comprised a total of 25 questions (Table S1).The questions were organized into three main sections: Socioeconomic aspects, which included questions on the age, gender, level of education, size of the property, landownership, availability of capital, and membership to an agriculture association.

2.
Occupational aspects, which included questions on crop and pest management, and information about pesticides used and practices in pesticide application.The participants were asked questions about the commercial name of the chemicals they use, on the dose of pesticides applied on crops, on the storage of such products, and on waste disposal.Additionally, questions about pesticide application methods, maintenance of the equipment used in the applications (leaks, repairs, etc.), and the use of personal protective equipment (PPE) (overall work clothing, gloves, and masks) were included.
A sub-section on health was also included, with questions on a self-evaluation of health status, and on the number of years they were in contact with pesticides.

3.
Knowledge aspects, which included questions on the sources of information about pesticides, technical assistance and guidance for pesticide use, modality of access to such information, and knowledge on the meaning of the colors and symbols on pesticide labels.
In the field, the data collection was performed by applying a mixed method, as the questionnaire was used during the interviews.The personal contact increased the response rate to the questionnaire and enhanced the potential to obtain data of the highest quality [37,38].The interviews were conducted in a friendly manner based on a strong relationship that was carefully built up between the surveyor and the participant.

Statistical Analysis
The minimum sample size was calculated according to the proportion method proposed by Corbetta [39] for social research.Based on the number of farmers in the Chancay-Huaral valley according to the last agricultural census [12], the minimum sample size should be 73 participants (n = 73) and 92 were interviewed.For the Chillón valley, the minimum sample size should be 14 (n = 14) participants, but the actual number of interviewed participants was 10 (n = 10) due to the scarcity of agricultural areas (and therefore of farmers/fieldworkers) within the Lima City Metropolitan area.Thus, the total sample size was 102 participants, comprising 92 from the Chancay-Huaral valley (90.2%) and 10 from the Chillón valley (9.8%).
The results from the questionnaire were analyzed using the mean and standard deviation (quantitative variables) and frequencies (categorical variables).The statistical significance of the results was set at an alpha value (α value) of 5%, i.e., corresponding to 95% confidence intervals.Duncan's test was used for the statistical assessment of categorical variables.All of the data were stored and processed using SPSS Statistics 19.0 (IBM, Chicago, IL, USA).The data regarding the self-evaluation of health for both valleys were processed together in order to allow for the calculation of epidemiological parameters, such as the odds ratio.The odds ratio (OR), a statistic parameter commonly used in epidemiology, allows for a comparison of two population groups with similar living conditions, one exposed to a risk factor (m i ) and the other not exposed to the risk factor (m o ), and quantifying the probability that a health detriment or disease will occur in the group exposed to the m i risk factor.The OR was calculated for two m i variables: (1) average age of initiation in the usage of pesticides (determined to be 15 years old) and (2) average lifelong exposure (average number of years using pesticides, determined to be 30 years).

Socioeconomic Aspects
The results from the socioeconomic section of the questionnaire-based interviews are illustrated in Figure 2.
Gender: A small percentage (4.3%) of the interviewed participants in the Chancay-Huaral valley were female farmers (i.e., landowners), while in the Chillón valley, all of the participants (100%) were male farmers.In total, despite the male predominance among the farmers in the study areas, 10% of agricultural properties were managed by women, who carry out agricultural activities in addition to their household and family-caring activities (Figure 2a).
Age: In both valleys, the age of the surveyed participants averaged 46.5 years old.Regarding the participant's age, the largest groups were in the age intervals of 35-45 and 46-65 years old.The youngest age group was from 15 to 25 years old (Figure 2b).
Origin and provenance: In both valleys, most of participants originated from rural areas (97.8% Chancay-Huaral valley, 90% Chillón valley), while a minority originated from urban areas (2.2% Chancay-Huaral valley, 10% Chillón valley).Regarding the place of origin, the percentage of participants that reported being native to the valley was variable (46.7% in the Chancay-Huaral valley, 30% in the Chillón valley), while more than 50% of participants were native to the mountain rural areas (highlands) (53.3% in the Chancay-Huaral valley, 70% in the Chillón valley) (Figure 2c,d).
Educational/instruction level: In the Chancay-Huaral valley, most participants reported to receiving basic education (19.6% completed and 23.9% did not complete primary school), secondary-level education (44.6% completed and 6.5% did not complete high school), and higher education (but not completed (2.2%)), while 3.3% reported to be illiterate.The participants from the Chillón valley were all literate, having received primary school (30% completed, 10% not completed), high school (40% completed, 10% not completed), and even higher education (but not completed (10%)) (Figure 2e).
Living conditions: In both valleys, 100% of participants reported living in houses with electricity and basic amenities, such as a tap water supply and wastewater/sanitary drainage (Figure 2f).
Occupational activities and landownership: In both valleys, the professional activities of the participants were linked to agricultural production and, in the case of the female farmers from the Chancay-Huaral valley, additional household and children caring tasks.In this valley, 46.7% of the participants were land-owning farmers, who considered themselves as small-scale farmers and medium-scale farmers according to the popular criteria described in Figure 3, while 53.3% were hired as temporary fieldworkers.In the Chillón valley, 30% of the respondents were farmers, while 70% were temporary fieldworkers.The farmers from both valleys indicated that more than 60% of the family income originates from the sales of their agricultural products.In contrast, fieldworkers indicated that they usually have to undertake two jobs, e.g., agricultural activities in morning and non-agricultural activities during the afternoon.Their salary from agricultural jobs contributed to 22% to 42% of the family income, while working in non-agricultural activities (trading, fishery-related activities, etc.) provided less than 20% to the household income (Figure 2g,h).Therefore, other members of the fieldworkers' families perform economical non-agricultural activities to help cover their basic household expenses.
In this valley, 46.7% of the participants were land-owning farmers, who considered themselves as small-scale farmers and medium-scale farmers according to the popular criteria described in Figure 3, while 53.3% were hired as temporary fieldworkers.In the Chillón valley, 30% of the respondents were farmers, while 70% were temporary fieldworkers.The farmers from both valleys indicated that more than 60% of the family income originates from the sales of their agricultural products.In contrast, fieldworkers indicated that they usually have to undertake two jobs, e.g., agricultural activities in morning and nonagricultural activities during the afternoon.Their salary from agricultural jobs contributed to 22% to 42% of the family income, while working in non-agricultural activities (trading, fishery-related activities, etc.) provided less than 20% to the household income (Figure 2g,h).Therefore, other members of the fieldworkers' families perform economical nonagricultural activities to help cover their basic household expenses.

Occupational Exposure Aspects
The results from the occupational exposure section of the questionnaire-based interviews are illustrated in Figure 4.
Crop and pest management: In both valleys, the farmers grow a wide range of cultivars (potato, maize, tomato, and other horticultural crops, and fruit crops such as apple, citrus, mango, and strawberry), whose production is mainly destined for the Lima City fresh market.According to responses obtained from the SSFs, the main insect pests affecting their crops occur in potato and horticultural crops and are the mining fly (Liriomyza huidobrensis), the "whitefly" complex (Bemisia tabaci and Trialeurodes vaporariorum, among others), and the bud-midge (Prodiplosis longifila); in maize crops, the main pests are the earthworm (Helicoverpa armigera), and in fruit crops and strawberry, the "scale" insects (from the Coccidae and Pseudococcidae families) and mites (the red mite Panonychus sp. and the hyaline mite Polyphagotarsonemus sp., among others).The most frequent crop disease mentioned by farmers was the "rancha" or "chilling fungus" (Phytophthora infestans) which occurs mostly in potato and tomato plantations.In terms of weeds, a large number of annual species of broad-and narrow-leaved weeds were mentioned.
Use of pesticides: The farmers stated that the application of pesticides is a common practice in the Chancay-Huaral and Chillón valleys because of the continuous pest pressure.For pesticide application, they follow the recommendations from visiting experts from agrochemical manufacturing companies and agrochemical shops (Figure 4a,b).The farmers concurred that a few decades ago, "there were less pests than today", and they did not know any other pest control method as efficient as the chemicals.From the commercial names of the pesticides declared by participants as being the commonly used, 36 active ingredients (AIs) were identified in both valleys (Table 1).The most widely used

Occupational Exposure Aspects
The results from the occupational exposure section of the questionnaire-based interviews are illustrated in Figure 4.
Agrochemicals 2024, 3, FOR PEER REVIEW 9 AIs were chlorpyriphos and metamidophos, which are organophosphate compounds, followed by methomyl, a carbamate compound.Less frequently used AIs were acetamiprid (a neonicotinoid compound), fosetyl aluminum (a phosphonate compound), kresoximmethyl (a strobilurin compound), and metalaxil-m (a phenylamide compound).Formulations with mixed compounds were also reported to be used, such as the pyraclostrobin + boscalid (strobilurin and carboxamide compounds) and paraquat (a bipyridyl compound) (Table 1).The organochlorine compound dicofol was also mentioned.Overall, for both valleys, the average number of pesticide applications per crop season was 6.1 (Figure 4d).Crop and pest management: In both valleys, the farmers grow a wide range of cultivars (potato, maize, tomato, and other horticultural crops, and fruit crops such as apple, citrus, mango, and strawberry), whose production is mainly destined for the Lima City fresh market.According to responses obtained from the SSFs, the main insect pests affecting their crops occur in potato and horticultural crops and are the mining fly (Liriomyza huidobrensis), the "whitefly" complex (Bemisia tabaci and Trialeurodes vaporariorum, among others), and the bud-midge (Prodiplosis longifila); in maize crops, the main pests are the earthworm (Helicoverpa armigera), and in fruit crops and strawberry, the "scale" insects (from the Coccidae and Pseudococcidae families) and mites (the red mite Panonychus sp. and the hyaline mite Polyphagotarsonemus sp., among others).The most frequent crop disease mentioned by farmers was the "rancha" or "chilling fungus" (Phytophthora infestans) which occurs mostly in potato and tomato plantations.In terms of weeds, a large number of annual species of broad-and narrow-leaved weeds were mentioned.
Use of pesticides: The farmers stated that the application of pesticides is a common practice in the Chancay-Huaral and Chillón valleys because of the continuous pest pressure.For pesticide application, they follow the recommendations from visiting experts from agrochemical manufacturing companies and agrochemical shops (Figure 4a,b).The farmers concurred that a few decades ago, "there were less pests than today", and they did not know any other pest control method as efficient as the chemicals.From the commercial names of the pesticides declared by participants as being the commonly used, 36 active ingredients (AIs) were identified in both valleys (Table 1).The most widely used AIs were chlorpyriphos and metamidophos, which are organophosphate compounds, followed by methomyl, a carbamate compound.Less frequently used AIs were acetamiprid (a neonicotinoid compound), fosetyl aluminum (a phosphonate compound), kresoxim-methyl (a strobilurin compound), and metalaxil-m (a phenylamide compound).Formulations with mixed compounds were also reported to be used, such as the pyraclostrobin + boscalid (strobilurin and carboxamide compounds) and paraquat (a bipyridyl compound) (Table 1).The organochlorine compound dicofol was also mentioned.Overall, for both valleys, the average number of pesticide applications per crop season was 6.1 (Figure 4d).
Pesticide storage: Most participants indicated that they store the pesticides and pesticide application equipment in specific rooms located away from their household and, more frequently, in the crop field (65.2% and 80% for the Chancay-Huaral and Chillón valleys, respectively).The storage room in the field is usually open, but when they finish their work day or leave, they usually lock the access to this room.A minority of responders indicated that they keep these products in a locked room inside the household (34.8% and 20% for the Chancay-Huaral and Chillón valleys, respectively) as a precaution against possible theft of their application equipment and pesticide reserves (Figure 4c).
Application of pesticides: The frequency and dose of pesticide application were very variable in both valleys.Approximately 50% (Chancay-Huaral) and 40% (Chillón) of the surveyed participants stated that they apply the dose recommended in the pesticide product label.However, around 50% of the respondents in both valleys increased the pesticide dose because "the recommended one is too low".Pesticide applications were made according to the schedule suggested by the farmer's advisors, as indicated above (item 3.2.2).Only 2.2% and 10% of the participants from the Chancay-Huaral and Chillón valleys, respectively, indicated that they use less pesticide than the recommended dose and apply pesticides only when the pest pressure and damage are evident, and this was because of economic reasons.In both valleys, vegetable crops received the highest rates of pesticide applications, while the fruit crops received pesticide applications less frequently.The highest frequency of pesticide application was every 4-5 days for vegetable crops (14.1% and 20% in Chancay-Huaral and Chillón valleys, respectively), while the lowest pesticide application frequency was two or three times for fruit crops per crop season (1.1% in Chancay valley) (Figure 4d,e).
Preparation of pesticides' solution: The participants from both valleys stated that the pesticide solution (pesticide compound + adherent + pH stabilizer) is prepared by farmers or by the leader of the applicator team (to avoid robbery of agrochemical products by fieldworkers).The respondents also mix different active ingredients to achieve "better controlling results" over the pests (Figure 4f).In all cases, the respondents did not wearing basic personal protective equipment (PPE), such as gloves and facial masks, but often used a wood stick or a PVC tube to mix the ingredients with water in a pail to avoid direct contact with the chemicals (Figures 4, 5 and 7).Several farmers (landowners) mentioned that they occasionally mix the pesticides with their own hands "when the product is not so strong".The farmers believe that the degree of poisoning (toxicity) of a pesticide can be inferred from the smell of the product: the product with the strongest the odor has the highest the toxicity.The pesticide mixture is commonly prepared in 200 L plastic tanks and the water used in the preparation is taken from the ditches that are usually available around the fields (Figure 5).During pesticide application campaigns, to refill the spraying equipment, workers bend into the 200 L tank, with their head and half of their body entering to reach the solution and, thus, they inhale vapors and contaminate their hands and chest (Figure 7).after having prepared the pesticide mix to be applied with a (non-portable) motor pump to fruit tree crops by fieldworkers (as shown in Figure 7c); (c) fieldworkers preparing the pesticide broth to be applied to a potato crop field, while the landowner, a medium-scale farmer, supervises; (d) a (smallscale) farmer refilling his manual backpack sprayer pump.In all cases, the farmhouse was located at the edge of the field where pesticide was applied, as can be noticed in (b,d).In all cases, the subjects were not using any personal protective equipment.
Pesticide application equipment: Most participants reported using 20 L spraying backpack drums, operated either manually (73.9% in the Chancay-Huaral valley, 60% in the Chillón valley) or with a motor pump (19.6% and 40% for the Chancay-Huaral and Chillón valleys, respectively) (Figure 4i).These 200 L tanks with a motor pump sprayer installed on a vehicle are used by 5.4% of the fruit-crop growers in the Chancay-Huaral valley.A minority (6.5%) indicated that they use 5 L manual spraying bottle pumps.The users of spraying pumps reported that their equipment is in acceptable functioning conditions (87% and 60% in the Chancay-Huaral and Chillón valleys, respectively) (Figure 4j), while a minority reported serious leaks in their equipment that usually wets their backs, legs, and feet during the application (12% in Chancay-Huaral and 40% in Chillón) (Figure 7).after having prepared the pesticide mix to be applied with a (non-portable) motor pump to fruit tree crops by fieldworkers (as shown in Figure 6c); (c) fieldworkers preparing the pesticide broth to be applied to a potato crop field, while the landowner, a medium-scale farmer, supervises; (d) a (small-scale) farmer refilling his manual backpack sprayer pump.In all cases, the farmhouse was located at the edge of the field where pesticide was applied, as can be noticed in (b,d).In all cases, the subjects were not using any personal protective equipment.In all cases, the subjects were not using any personal protective equipment, and the preparation of the pesticide mix was performed close to the irrigation ditches.The ditches around the field were used to provide water for the pesticide mix, and to discard the remainders of the pesticide mix.
Exposure of family members during pesticide application: Family members often help during the application, especially children and adolescents and preferably males (Figures 4k and 8b).In the Chancay-Huaral valley, 95.7% of the participants indicated that their family is frequently in the field during the pesticide application, and in the Chillón valley, this was confirmed by 80% of participants (Figure 4k).
Disposal of pesticide residues and pesticide containers: All participants mentioned that the solution remnants or excesses (usually a quarter of liter, approximately) are disposed of by tossing them into the water stream ditches, while empty pesticide containers are usually thrown onto the ground by the edge of crop fields or into the nearest irrigation ditch (Figure 6).
Workers' hygiene after the application: Most participants reported taking a shower and changing their clothes immediately after pesticide application (85.9% and 80% in the Chancay-Huaral and Chillón valleys, respectively).There were participants that reported that they wash their hands only (5.4% in Chancay-Huaral valley) and drink milk as a health protector (3.3% and 10% in the Chancay-Huaral and Chillón valleys, respectively), while some participants reported not taking a shower but changing clothes if they were wetted by the pesticide solution during the application (3.3% and 10% in Chancay-Huaral and Chillón valleys, respectively).The details are shown in Figure 4l.In all cases, the subjects were not using any personal protective equipment, and the preparation of the pesticide mix was performed close to the irrigation ditches.The ditches around the field were used to provide water for the pesticide mix, and to discard the remainders of the pesticide mix.
Protective measures: Approximately 73.9% and 70% of the participants in the Chancay-Huaral and Chillón valleys, respectively, reported not using PPE (Figure 4h).A minority of participants wear boots and plastic aprons improvised with empty fertilizer plastic bags and dust-protective masks to cover the mouth and nose as their usual protection during pesticide application (Figures 5-7).All participants reported receiving pesticide sprays on their faces, hands, legs, feet, and even their backs-this latter exposure was due to leaks in the spraying equipment-during the application of pesticides.Their lower limbs and feet were mostly contaminated when the crop plants are tall (potato crop, for example), and especially during winter because of the presence of mist and/or dew in the mornings, which makes water condensation slip from the plant leaves to their legs and enter their boots.All the participants pointed out that PPE is a missing item in the agrochemical trade houses and stores and, when in stock, the price is not affordable.Additionally, they indicated that PPE is uncomfortable, making them to sweat significantly more than when working without PPE.
Pesticide application equipment: Most participants reported using 20 L spraying backpack drums, operated either manually (73.9% in the Chancay-Huaral valley, 60% in the Chillón valley) or with a motor pump (19.6% and 40% for the Chancay-Huaral and Chillón valleys, respectively) (Figure 4i).These 200 L tanks with a motor pump sprayer installed on a vehicle are used by 5.4% of the fruit-crop growers in the Chancay-Huaral valley.A minority (6.5%) indicated that they use 5 L manual spraying bottle pumps.The users of spraying pumps reported that their equipment is in acceptable functioning conditions (87% and 60% in the Chancay-Huaral and Chillón valleys, respectively) (Figure 4j), while a minority reported serious leaks in their equipment that usually wets their backs, legs, and feet during the application (12% in Chancay-Huaral and 40% in Chillón) (Figure 6).
Exposure of family members during pesticide application: Family members often help during the application, especially children and adolescents and preferably males (Figures 4k and 8b).In the Chancay-Huaral valley, 95.7% of the participants indicated that their family is frequently in the field during the pesticide application, and in the Chillón valley, this was confirmed by 80% of participants (Figure 4k).Disposal of pesticide residues and pesticide containers: All participants mentioned that the solution remnants or excesses (usually a quarter of liter, approximately) are disposed of by tossing them into the water stream ditches, while empty pesticide containers are usually thrown onto the ground by the edge of crop fields or into the nearest irrigation ditch (Figure 7).
Workers' hygiene after the application: Most participants reported taking a shower and changing their clothes immediately after pesticide application (85.9% and 80% in the Chancay-Huaral and Chillón valleys, respectively).There were participants that reported that they wash their hands only (5.4% in Chancay-Huaral valley) and drink milk as a health protector (3.3% and 10% in the Chancay-Huaral and Chillón valleys, respectively), while some participants reported not taking a shower but changing clothes if they were wetted by the pesticide solution during the application (3.3% and 10% in Chancay-Huaral and Chillón valleys, respectively).The details are shown in Figure 4l.
Lifelong exposure to pesticides: All participants indicated having been involved in handling and/or application of pesticides since early ages.In landowner families, the age of initiating exposure to pesticides was 5 or 6 years old, generally helping the father to manipulate the spraying equipment and chemical products during the preparation of pesticide solutions (Figure 9a).A period of (probable) non-contact to pesticides was observed for the medium-scale farmers, as after the high school, children usually leave the parent's house and move to Lima City to pursue their higher education (university).In some cases, they return home approximately 10 years later to take the lead in managing the family farm.In the case of fieldworkers, they start handling pesticides around 14-16 years old, mostly working as pesticide applicators, which was mentioned to be the most common task for temporary workers.
for the medium-scale farmers, as after the high school, children usually leave the parent's house and move to Lima City to pursue their higher education (university).In some cases, they return home approximately 10 years later to take the lead in managing the family farm.In the case of fieldworkers, they start handling pesticides around 14-16 years old, mostly working as pesticide applicators, which was mentioned to be the most common task for temporary workers.Self-evaluation of health condition: All of the respondents from the two valleys reported having suffered from illnesses which they believe to be linked to pesticide use.In both valleys, the participants reported skin allergies (11%), frequent headaches (17.4%), stomach pain (13%), respiratory distress (16.3%), and visual illnesses (43.5%), among others (more details shown in Table 2).Only 4% of the participants from the Chancay-Huaral valley asked for medical assistance, while 40% from the Chillón valley did so.Additionally, 3.3% from the Chancay-Huaral valley mentioned having suffered from acute organophosphate poisoning at least once.
Table 2. Health issues or illnesses related to the usage of pesticides according to the participants from the Chancay-Huaral and Chillón valleys in Peru.The second column refers to the number of times the illness was mentioned by participants, i.e., the relevance or prevalence of the illness in direct users of pesticides.The third and fourth columns show the odds ratios (ORs) for these illnesses according to the age of initiation in the usage of pesticides (average of 15 years old) and the lifetime exposure to pesticides (number of years using pesticides; average: 30), respectively.The results are based on the total number of participants from the two valleys (n = 102) (* = statistically significant).Self-evaluation of health condition: All of the respondents from the two valleys reported having suffered from illnesses which they believe to be linked to pesticide use.In both valleys, the participants reported skin allergies (11%), frequent headaches (17.4%), stomach pain (13%), respiratory distress (16.3%), and visual illnesses (43.5%), among others (more details shown in Table 2).Only 4% of the participants from the Chancay-Huaral valley asked for medical assistance, while 40% from the Chillón valley did so.Additionally, 3.3% from the Chancay-Huaral valley mentioned having suffered from acute organophosphate poisoning at least once.

Health Issue or
Table 2. Health issues or illnesses related to the usage of pesticides according to the participants from the Chancay-Huaral and Chillón valleys in Peru.The second column refers to the number of times the illness was mentioned by participants, i.e., the relevance or prevalence of the illness in direct users of pesticides.The third and fourth columns show the odds ratios (ORs) for these illnesses according to the age of initiation in the usage of pesticides (average of 15 years old) and the lifetime exposure to pesticides (number of years using pesticides; average: 30), respectively.The results are based on the total number of participants from the two valleys (n = 102) (* = statistically significant).

Knowledge Aspects
The results from the knowledge (information) section of the questionnaire-based interviews are illustrated in Figure 10.

Discussion
Our results are in agreement with those of recent studies carried out in Peru regarding the use of pesticides in food production [40,41].Therefore, according to these research works and the successive monitoring visits of our team to the study area during recent years, it can be stated that, despite the time that elapsed, they still reflect the current situation in the Chancay-Huaral and Chillón valleys.

Gender, Educational Level, Provenance, and Land Ownership
In both valleys, the vast majority of participants were male, which is in agreement with results of the IV National Agricultural Census carried out in Peru in 2012 [4].The 2012 census revealed that men contribute to 69.2% of the agricultural workforce, while women only represented 30.8%.This conspicuous male status in agricultural activities has been described earlier in Latin America countries by Mera-Orces [42].
Land-owner farmers native to the valleys under study have the highest educational level.In particular, the medium-scale farmers had completed secondary education, while small-scale farmers had not complete primary and/or incomplete secondary education.In contrast with this, the fieldworkers native to the highlands (immigrants in coastal valleys) had the lowest education level with either a complete or incomplete primary school education and even illiteracy.These fieldworkers are hired to spray pesticides without any previous training, and are therefore being especially vulnerable to intoxication.Their illiteracy complicates the knowledge transfer process and, thus, illiterate fieldworkers need a special training program for information on pesticide use and safety.
Land ownership in the investigated valleys can be classified on the basis of land area and financial resources using the criteria followed by the National Institute of Statistics and Informatics of Peru [6], reducing the farmer categories from six to three categories (Figure 3): Technical assistance: In the Chancay-Huaral valley, only 4.3% of the participants reported not receiving any technical assistance or training (Figure 10a).They stated that they know what pesticide to buy based on their previous experience, but they also expressed interest in receiving technical assistance from sources not connected to commercial houses and agrochemical manufacturing companies.In both valleys, many participants mentioned that they are frequently visited by engineers from agrochemical companies who provided technical advice at no charge (Chancay-Huaral: 56.8%; Chillón: 30%).Similarly, sales agents based in local agrochemical trading houses also assume the role of technical advisors (Chancay-Huaral: 26.1%; Chillón: 40%) (Figure 10b).The participants stated that they buy the products recommended by these two types of technical advisors, who commonly recommend buying a list of products, either for controlling the pest/disease or for pest/disease prevention.
Knowledge on the risk of exposure to pesticides: Regarding the knowledge on the toxicity level of pesticides, 41.3% and 50% of the respondents from the Chancay-Huaral and Chillón valleys, respectively, stated that they are aware of the meaning of the color of labels on pesticides.Nevertheless, very few were able to explain the meanings without confusion.The other 58.7% and 50% (from Chancay-Huaral and Chillón valleys, respectively) indicated that they are unaware of the relationship between the color of labels and pesticide toxicity.Similar percentages were obtained by asking about the meaning of the symbols on the labels of chemical products.Most of the respondents said they knew their meaning, but, similarly, only very few were able to explain them in a clear manner (Figure 10c,d).

Discussion
Our results are in agreement with those of recent studies carried out in Peru regarding the use of pesticides in food production [40,41].Therefore, according to these research works and the successive monitoring visits of our team to the study area during recent years, it can be stated that, despite the time that elapsed, they still reflect the current situation in the Chancay-Huaral and Chillón valleys.

Gender, Educational Level, Provenance, and Land Ownership
In both valleys, the vast majority of participants were male, which is in agreement with results of the IV National Agricultural Census carried out in Peru in 2012 [4].The 2012 census revealed that men contribute to 69.2% of the agricultural workforce, while women only represented 30.8%.This conspicuous male status in agricultural activities has been described earlier in Latin America countries by Mera-Orces [42].
Land-owner farmers native to the valleys under study have the highest educational level.In particular, the medium-scale farmers had completed secondary education, while small-scale farmers had not complete primary and/or incomplete secondary education.In contrast with this, the fieldworkers native to the highlands (immigrants in coastal valleys) had the lowest education level with either a complete or incomplete primary school education and even illiteracy.These fieldworkers are hired to spray pesticides without any previous training, and are therefore being especially vulnerable to intoxication.Their illiteracy complicates the knowledge transfer process and, thus, illiterate fieldworkers need a special training program for information on pesticide use and safety.
Land ownership in the investigated valleys can be classified on the basis of land area and financial resources using the criteria followed by the National Institute of Statistics and Informatics of Peru [6], reducing the farmer categories from six to three categories (Figure 3): (1) Large-scale farmers, owning more than 20 hectares.They make large capital investments in crops and technology, hire a significant workforce, and produce for export.(2) Medium-scale farmers, owning more than 5 and up to 20 hectares.They also make significant capital investments, but their families work in the field as well.Their products are mostly intended for the local market, mainly Lima city, but occasionally could be exported as well.
(3) Small-scale farmers, owning up to 5 hectares of land.They lack financial resources to invest, and their families work in field and provide most of the labor.Often, these SSFs do not own land, but they lease it from third parties and they live on the land while performing their agricultural and complementary activities.

Socioeconomic and Educational Aspects and Risk of Exposure to Pesticides
Unsafe pesticide management practices with a high risk of exposure were observed in both the Chancay-Huaral and Chillón valleys.Compared to landowner farmers, the hired fieldworkers are the most exposed ones because the application of pesticides is their main activity, and it is performed several times a day.Getting their clothes and body wet with the pesticide solution was frequently reported in both valleys, and this was related to application equipment (sprayers) with leaks and the lack of proper PPE, which in turn was associated with a scarcity of economic resources for farmers to invest in the equipment and their adequate maintenance.
It was observed that the scarce education and lack of training are directly linked to unsafe practices in pesticide handling and application.The most hazardous practice described by the fieldworkers occurs when the nozzles are obstructed during pesticide application.To overcome this problem, workers place the nozzle on their mouth and blow strongly to clean it.It was also noticed that fieldworkers often spray the pesticide against the wind, which further increases the risk of intoxication through pesticide inhalation and dermal absorption.
The exposure to pesticides may occur for all members of the family, especially among the SSFs, because women, children, and pets are often present at the field during pesticide applications, thus inhaling the pesticide solution mist dispensed by the sprayer (Figure 8).Furthermore, all family members can come into direct contact with the crops a few hours after the application, and children are allowed to play with the wood sticks used to mix the pesticide solution.Additionally, as stated by fieldworkers' spouses, the fieldworkers' clothes used during the application of pesticides are washed together with the family's clothes, which can lead to an additional dermal exposure for all the family members to pesticides.
In both the Chancay-Huaral and Chillón valleys, less than 50% of the respondents reported taking into account the safety warnings displayed on the pesticide containers through the color of labels and symbols.The majority of them reported ignoring the instructions provided on the labels and the instructions for the application of the chemical.No respondent was aware of the potential development of pest resistance and emergence of new pests as a consequence of the incorrect use of pesticides.These results coincide with those from a study carried out in Ecuador, where the surveyed farmers reported that "new pests" have appeared, but without associating their emergence with pesticide use [43][44][45].This convergence of results at the regional level revealed a lack of technical knowledge on pest management, on the risk of exposure to pesticides, and on pesticides' effects on human health and the environment.Clearly, socioeconomic and educational factors are intimately connected to the actual exposure to pesticides.
During the last twenty years, several institutions have trained thousands of smallscale farmers in pest management strategies and attempted to implement integrated pest management (IPM) programs as an alternative to the use of synthetic pesticides.Nevertheless, after the project conclusion, the farmers returned to the conventional use of pesticides [46,47].To successfully counteract such a relapse requires a strong permanent framework by SENASA and INIA, together with non-governmental institutions and the private sector.It must be highlighted that the information provided by commercial speeches cannot replace the settlement of an official body providing independent information and accurate scientific advice on the existing and emerging risks associated with the food chain in Peru.

Pesticide Residues, Farmers' Education Level, and Waste Management Policy
The disposal of empty pesticide containers and remaining pesticide solutions into ditches around crop fields, into water ways, and onto the soil is a common practice and represents a serious environmental concern in the Chancay-Huaral and Chillón valleys.Due to the close proximity of the agricultural valleys to the coast, these residues could reach the Pacific Ocean (Figure 8a).
According to the General Law of Solid Waste of Peru, pesticide containers are classified as hazardous waste and should not be disposed of with common household and agricultural waste.However, there is no country-wide policy and no system for collecting pesticide containers in rural areas of Peru [47].Some local initiatives from the private sector, local authorities, and civil society emerged during the last few decades, such as "Campo Limpio" that was introduced in 2006, which collects empty pesticide containers, but not in a sufficient amount [47,48].
The results revealed that environmental pollution due to the pesticides used in agriculture is triggered by the low educational level of farmers and by the absence of policies for the correct disposal of pesticide residues and contaminated waste.

Informal and Biased Agrochemical Advice to Farmers
Small-scale farmers from both valleys stated in the interviews that they prefer using pesticides to fight pests due to their effectiveness-which is interpreted by SSFs as a rapid mortality of the target pest, their easy usage, and the little physical effort required for application.
The absence of an official advisory service in agriculture favors informal advisory services to farmers that is provided by agrochemical producers and agrochemical salespersons.These, instead of providing a real help to farmers, primarily focus on increasing sales and for this goal, they offer a number of 'presents' (e.g., t-shirts, cups, and items publicizing their agrochemicals) in order to generate 'confidence' and to facilitate acceptance of their suggestions on agrochemical selection and application rates.These findings are in agreement with those reported by Beyer et al. [11] and Cruz-Escalon [45].The latter also reported that small-scale farmers with limited economic resources commonly buy the cheapest pesticide (also recommended by salespersons), which usually contains the more toxic AIs and displays the widest target effectiveness [47].
Therefore, an official agrochemical/agricultural advisory service is needed to eradicate informal and commercially biased advisory services offered to farmers.

Role of Official Agencies in Establishing Guidelines on Agrochemicals
According to the list published by the National Service of Agrarian Sanity of Peru [49], aldicarb and methamidophos, two pesticides that were banned and/or are under restricted use, are widely used in the Chancay-Huaral and Chillón valleys.Paraquat, another banned herbicide, was listed as commonly used by farmers (Table 1).These findings show either a deficient supervision or lack of regulation enforcement by competent authorities, as was already identified by several authors [11,13,14,25,50,51].
The organochlorine pesticide dicofol was reported to be used by the farmers participating in this study.This is particularly worrisome because dicofol is extremely toxic to mammals, birds, and aquatic organisms, causing chronic effects above the no observed effect concentration (NOEC) values of 4.4-125 µg/L [52,53].Dicofol is on the banned/restricteduse pesticide list of many countries, particularly in the signatories to the Stockholm and Rotterdam Conventions.Peru is a party of these conventions [52,[54][55][56][57]. Nevertheless, up to 2023, SENASA-Peru did not include dicofol in the list of banned pesticides, although the AI chlorpyriphos, one of the most commonly used pesticides according to our data, had been included in the list of banned pesticides in 2023 [58].
In the Chancay-Huaral and Chillón valleys, the pesticide sale centers (trading houses) are located side by side with places that sell food such as restaurants and grocery stores, both in rural and central urban areas.In fact, this occurs across the country, especially in the highlands [13].This proximity represents a serious potential health hazard due to the frequent inadequate storage of agrochemicals and exposure of foods to these chemicals.In the case of an explosion, fire, or a spill involving such agrochemical stocks, the surrounding population and places selling food can be affected [13,49].Therefore, safety rules and the intervention of local and national authorities in these matters seem crucial to improve safety measures in order to avoid any potential disaster with implications on public health [49].
The current and deficient role of official agencies in enforcing the current norms on the safe storage and use of agrochemicals actually contributes to the incorrect and unsafe storage, handling, and application of pesticides.

Lifelong Exposure to Pesticides and Workers' Health
According to the questionnaire results obtained in both valleys, the average age of starting to manipulate pesticides was 15 years.As the average age of the participants was 47.6 years, at the time of the interview, most participants had already endured a long-term exposure to pesticides averaging 30 years.The lack of personal protective equipment, combined with the use of deficient spraying equipment, certainly exacerbated the risk of acute and chronic intoxication during this long-term exposure and, consequently, may have affect the workers' health condition and life span (Table 2).Indeed, health issues that were frequently reported by the participants could be related to the improper handling of pesticides.
The data available from the hospital of Chancay district for the 1992 to 1997 period recorded acute intoxication episodes of unintentional poisoning by agrochemicals in the Chancay-Huaral valley [50].These episodes matched with the farmer interview results in the valley.Furthermore, the results of Sarabia-Nuñez et al. [14] demonstrated decreased levels of the liver enzyme plasmatic cholinesterase (BchE) and leucopenia in adult individuals from Huando, a fruit-grower village in the Chancay-Huaral valley, after applying methomyl.These results were in agreement with those of a study in the Chancay-Huaral valley in 2005, which suggested that the chronic pesticide poisoning in small-scale farmers in the Huaral district was due to an extended exposure time over the many years in which they applied pesticides [53].
Therefore, although pesticides allow for a public benefit by increasing agricultural productivity, they pose a health risk to users, consumers, and the environment (fauna, flora, water, and soil).

Conclusions
Taking the main food supplier agricultural valleys located near Lima City as a pilot study area, the present work gathered key information on the agricultural practices in Peru regarding the use of agrochemicals.
The results, from both among landowners and fieldworkers, revealed a widespread lack of training and lack of sound knowledge on pesticide toxicity and occupational exposure hazards since the agricultural practices were mainly oriented by the biased advice offered by agrochemical producers and salespersons.
The results of the survey demonstrated that despite the proximity of these agricultural areas to Lima City, it did not ensure better access to technical information, training, and trusted advisory services on agrochemicals for farmers.Nevertheless, the proximity to Lima City still ensured better access to education and health services, as participants from the Chillón valley were all literate and had better access to medical services when compared to those from the Chancay-Huaral valley.
This work also demonstrated that socio-economical, occupational, and informative aspects are linked with the risk of exposure to pesticides.A low education/instruction level or no education (illiteracy) was strongly associated with a higher exposure to pesticides and, consequently, was associated with a higher risk of self-intoxication, intoxication of family members, and enhanced environmental contamination by pesticides.This relationship may explain the increasing number of intoxication cases caused by agrochemicals that have been observed over the last two decades in Peru.
An important additional finding was the acknowledgement of the role of women in coastal farming as field managers, which they performed with taking care of the household.Therefore, women may potentially play a key role in the whole family's safety and this should be encouraged.
The low number of participants (n = 10) from the Chillón valley, below the recommended minimum sample size (n = 14), might have introduced bias into the results, but the key findings likely would remain unchanged.
In general, the results from this survey point out an urgent need for implementing a capacity-building program on the safe use of pesticides, along with an integrated pest management program in the studied areas in order to alleviate pesticide usage and to abate the noxious effects of pesticides on human health and the environment.Some ongoing programs can be taken as a model as a foundation (such as the US Environmental Protection Agency's Agricultural Worker Protection Standard, the Pesticide Risk Assessment Procedure and Solutions of the European Food Safety Authority, and the Code of Practice for Using Plant Protection Products of the United Kingdom, among others), with adaptation to the characteristics of the agricultural systems in Peru.
Competent official agencies in the implicated sectors, such as SENASA and the relevant ministries (e.g., agriculture, health, education), should launch a program for epidemiological surveillance of the population that is at risk.This could be part of a permanent pesticide management system including the control of the pesticide trade and storage, both in the Chancay-Huaral and Chillón valleys and at a country-wide level.Such a policy could greatly contribute to decreasing the environmental contamination by pesticide residues and reducing the number of intoxication cases.Furthermore, it would contribute to achieving the Sustainable Development Goals of the United Nations 2030 Agenda in Peru.

1 .
The valley of the Chancay-Huaral, which was shaped by the Chancay River originating in the western Andes of Raura (Canta province, Lima region).The Chancay River extends for approximately 120 km and has a watershed area of 3200 km 2 .This river discharges into the Pacific Ocean 77 km north of Lima City and 6 km south of the district of Chancay.The areas of the Chancay-Huaral valley under study were Retes, extends for approximately 120 km and has a watershed area of 3200 km 2 .This river discharges into the Pacific Ocean 77 km north of Lima City and 6 km south of the district of Chancay.The areas of the Chancay-Huaral valley under study were Retes, La Esperanza (Alta and Baja), Huayán, Jesús del Valle, La Huaca, Aucallama, Esquivel, Torre Blanca, Laure, and Chancayllo, as indicated in Figure1.2.The valley of the Chillón River, which is located 20 km north of the center of LimaCity.The Chillón River originates in the Chonta lagoon of the Andean mountains, province of Canta, and flows through the districts of Carabayllo, Puente Piedra, Ventanilla, and part of Comas, Los Olivos, and San Martín de Porras, all integrated in metropolitan Lima (Lima City).The river has a length of 126 km, a watershed area of 2444 km 2 , and discharges into the Pacific Ocean.The areas of the Chillón valley investigated were the current agricultural areas in the districts of Los Olivos, Comas, and Carabayllo (Figure1).

Figure 1 .
Figure 1.Location of the study area.Notice the proximity of the Chancay-Huaral and Chillón valleys-both highlighted in red circles-to the Lima City center (Lima, Rímac River basin).The map shows the three rivers-Rímac, Lurín, and Chillón-as light-blue solid lines.Currently, these rivers flow through the Lima Metropolitan Area, shown as dashed dark-blue lines (Source: Google Maps 2024).

Figure 1 .
Figure 1.Location of the study area.Notice the proximity of the Chancay-Huaral and Chillón valleys-both highlighted in red circles-to the Lima City center (Lima, Rímac River basin).The map shows the three rivers-Rímac, Lurín, and Chillón-as light-blue solid lines.Currently, these rivers flow through the Lima Metropolitan Area, shown as dashed dark-blue lines (Source: Google Maps 2024).

Figure 3 .
Figure 3. Differences between popular (widely used by farmers) and official (used by official Governmental agencies) criteria for classification of farmers based on the size of their agricultural land property.

Figure 3 .
Figure 3. Differences between popular (widely used by farmers) and official (used by official Governmental agencies) criteria for classification of farmers based on the size of their agricultural land property.

Figure 4 .
Figure 4. Results for occupational exposure from the questionnaire-based survey in the Chancay-Huaral and Chillon valleys.Total sample size = 102 respondents (Chancay-Huaral valley n = 92; Chillon valley n = 10).AI = active ingredient; PPE* = personal protection equipment as understood by farmers and fieldworkers, i.e., a piece of plastic bag on the front body to avoid becoming wet through contact with the plants where the pesticide solution was already applied (A clear example of this sort of PPE can be seen further in Figure 7a).

Figure 4 .
Figure 4. Results for occupational exposure from the questionnaire-based survey in the Chancay-Huaral and Chillon valleys.Total sample size = 102 respondents (Chancay-Huaral valley n = 92; Chillon valley n = 10).AI = active ingredient; PPE* = personal protection equipment as understood by farmers and fieldworkers, i.e., a piece of plastic bag on the front body to avoid becoming wet through contact with the plants where the pesticide solution was already applied (A clear example of this sort of PPE can be seen further in Figure7a).

Figure 5 .
Figure 5. Preparation of the pesticide mix in the Chancay-Huaral and Chillon valleys.(a) A smallscale farmer using a 200 L plastic cylinder and a wood stick for mixing; (b) a medium-scale farmerafter having prepared the pesticide mix to be applied with a (non-portable) motor pump to fruit tree crops by fieldworkers (as shown in Figure7c); (c) fieldworkers preparing the pesticide broth to be applied to a potato crop field, while the landowner, a medium-scale farmer, supervises; (d) a (smallscale) farmer refilling his manual backpack sprayer pump.In all cases, the farmhouse was located at the edge of the field where pesticide was applied, as can be noticed in (b,d).In all cases, the subjects were not using any personal protective equipment.

Figure 5 .
Figure 5. Preparation of the pesticide mix in the Chancay-Huaral and Chillon valleys.(a) A smallscale farmer using a 200 L plastic cylinder and a wood stick for mixing; (b) a medium-scale farmerafter having prepared the pesticide mix to be applied with a (non-portable) motor pump to fruit tree crops by fieldworkers (as shown in Figure6c); (c) fieldworkers preparing the pesticide broth to be applied to a potato crop field, while the landowner, a medium-scale farmer, supervises; (d) a (small-scale) farmer refilling his manual backpack sprayer pump.In all cases, the farmhouse was located at the edge of the field where pesticide was applied, as can be noticed in (b,d).In all cases, the subjects were not using any personal protective equipment.

Figure 7 .
Figure 7. Pesticide applicators in the Chancay and Chillon valleys, Peru.(a) Application of pesticides to potato crop using a motor pump.The worker uses an apron made of a plastic fertilizer bag as a sort of personal protection equipment (PPE); (b) application using a manual sprayer pump without PPE in a strawberry plantation; (c) application to avocado trees using a high-pressure pump, commonly used for fruit tree crops, without PPE; and (d) application of pesticides using a 20 L sprayer motor pump to lettuce, a field crop located behind a primary school.In all cases, non-proper or no PPE was used by the farmers (b) nor by the fieldworkers (a,c,d).

Figure 6 .
Figure 6.Pesticide applicators in the Chancay and Chillon valleys, Peru.(a) Application of pesticides to potato crop using a motor pump.The worker uses an apron made of a plastic fertilizer bag as a sort of personal protection equipment (PPE); (b) application using a manual sprayer pump without PPE in a strawberry plantation; (c) application to avocado trees using a high-pressure pump, commonly used for fruit tree crops, without PPE; and (d) application of pesticides using a 20 L sprayer motor pump to lettuce, a field crop located behind a primary school.In all cases, non-proper or no PPE was used by the farmers (b) nor by the fieldworkers (a,c,d).

Figure 6 .
Figure 6.Materials and tools used to refill the sprayer-pump container during pesticide application in the Chancay-Huaral and Chillon valleys.(a) A 200 L cylinder with a wood stick used for stirring the pesticide mix, and the pail used for refilling the pump tanks; (b) the person who prepares the pesticide mix is in charge of refilling the sprayer tank of the applicators using a pail; (c) a fieldworker mixing and preparing a refilling bucket; (d) a farmer refilling his 20 L manual sprayer backpack using a pail.In all cases, the subjects were not using any personal protective equipment, and the preparation of the pesticide mix was performed close to the irrigation ditches.The ditches around the field were used to provide water for the pesticide mix, and to discard the remainders of the pesticide mix.

Figure 7 .
Figure 7. Materials and tools used to refill the sprayer-pump container during pesticide application in the Chancay-Huaral and Chillon valleys.(a) A 200 L cylinder with a wood stick used for stirring the pesticide mix, and the pail used for refilling the pump tanks; (b) the person who prepares the pesticide mix is in charge of refilling the sprayer tank of the applicators using a pail; (c) a fieldworker mixing and preparing a refilling bucket; (d) a farmer refilling his 20 L manual sprayer backpack using a pail.In all cases, the subjects were not using any personal protective equipment, and the preparation of the pesticide mix was performed close to the irrigation ditches.The ditches around the field were used to provide water for the pesticide mix, and to discard the remainders of the pesticide mix.

Figure 7 .
Figure 7. Pesticide applicators in the Chancay and Chillon valleys, Peru.(a)Application of pesticides to potato crop using a motor pump.The worker uses an apron made of a plastic fertilizer bag as a sort of personal protection equipment (PPE); (b) application using a manual sprayer pump without PPE in a strawberry plantation; (c) application to avocado trees using a high-pressure pump, commonly used for fruit tree crops, without PPE; and (d) application of pesticides using a 20 L sprayer motor pump to lettuce, a field crop located behind a primary school.In all cases, non-proper or no PPE was used by the farmers (b) nor by the fieldworkers (a,c,d).

Figure 8 .
Figure 8. Presence of family (women and children) at the field during and after the application of pesticides to crops.(a) A family member checking whether the application reached the target pest a few hours after it was carried out; (b) family members (mother and children) covering seedlings with plastic to protect them from the herbicide that the father is applying beside them; (c) women at the edge of the fields waiting their partners to finish the application of pesticides; (d) a boy carrying his pet while his father performs an application of pesticide in the same field.

Figure 8 .
Figure 8. Presence of family (women and children) at the field during and after the application of pesticides to crops.(a) A family member checking whether the application reached the target pest a few hours after it was carried out; (b) family members (mother and children) covering seedlings with plastic to protect them from the herbicide that the father is applying beside them; (c) women at the edge of the fields waiting their partners to finish the application of pesticides; (d) a boy carrying his pet while his father performs an application of pesticide in the same field.

Table 1 .
Pesticides per active ingredient (AI) used by participants from the Chancay and Chillón valleys (n = 102) according to the interviews carried out in 2011.N • = AI rank number based on the number of participants reporting its use in responses to the questionnaire.The results sum up more than 100% because each participant could mention more than one pesticide (AI).OP = organophosphorous compounds.Degree of statistical significance according to the Duncan test is indicated by asterisks.Data regarding environmental fate, ecotoxicity fate, and human health have been gathered from the Pesticide Properties Data Base (PPDB) of the University of Hertfordshire, and from the website chemicalbook.com.High alert Bird acute LD 50 : 24.02 mg kg −1 .Honeybee contact acute LD 50 : 0.16 µg bee −1 .Acute and chronic toxicity for fauna.High alert Bird acute LD 50 : 10 mg kg −1 .Honeybee oral acute LD 50 : >0.22 µg bee −1 .Acute contact and oral toxicity for fauna.