الفهرس 
INTRODUCTION AND AIM OF THE WORKOnly 14 pages are availabe for public view
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Abstract
Fruits and vegetables make up, on average, 30% (based on mass) of the food consumed, according to the World Health Organization. These items are likely to have greater pesticide residue levels than other food categories of plant origin, such as foods based on processing, since they are often ingested semi-processed or raw.
In Palestine, the use of pesticides has greatly increased to enhance agricultural productivity, which is one of the primary economic and food-producing sectors for Palestinians, contributing 5.6% of gro ss domestic product (GDP) and 21% of exports . According to the Palestine Economic Policy Research Institute-MAS, chemical pesticides are the primary method used to manage pests and diseases on crops on around 57% of the total agricultural area in Palestine, primarily in irrigated and intensive cultures.
The aim of this study is to assess the risk of pesticide residues in some fresh vegetables in Tulkarm, Palestine.
To fulfill this aim, the study was conducted at three central vegetable markets and households of different locations in the Tulkarm Governorate: Tulkarm City, Tulkarm Camp, and Anabta Village. A cross-sectional study design including social survey and laboratory analysis were performed. A total of 384 Participants included adults, households’ subjects living in the selected three areas of Tulkarm Governorate were selected. Six types of fresh vegetables, including tomato, cucumbers, green onion, thyme, parsley, and lettuce were included. Pesticides were extracted from the samples using the QuEChERS technique, which allows different chemical groups of pesticides to be determined. selection of pesticides residues was based on the most probable chemical groups including organophosphates, carbamates, and organochlorines that are used in fruits and vegetables.
The risk assessment is computed by comparing the actual acceptable daily intake (ADI) with the applicable estimated acceptable daily intake (EDI), which is dependent on pesticide residue concentrations and food consumption. Only pesticide residues that exceeded the maximum residual limits were subject to risk assessment.
The results of the present study revealed that:
1- Consumer’s consumption and practices during purchasing fresh vegetables.
• Most of the study subjects (96.7%) consumed fresh vegetables, while only 3.3% did not.
• Vegetables were consumed by nearly half of the participants (48.1%) at 2-3 times per day, and by 32.5% once daily.
• Vegetables were purchased from grocers by 59.2% of the participants, from hesba by 40.4%, and from street sellers by 25.4% of the participants.
• Most respondents (86.3%) washed their vegetables before using it, 92.1% kept their vegetables in the refrigerator, 24.6% consumed it the same day, and 11.9% frozen it.
2- Pesticide residues in vegetables
• Pesticide residues were detected in 34 samples out of 36 tested samples of vegetables representing 94.4% contamination. Only 2 samples (6.6%) had no pesticide residues.
• The number of detected pesticides in all vegetable samples were 33 compounds.
• The number of detected pesticides in cucumber samples was 16 compounds, while it was 13 in each of lettuce and onion, 3 compounds in parsley, 5 in thyme, and 15 in tomatoes.
• The most frequently detected pesticides were difenoconazole (22 samples) and imidaclopride (21 samples) followed by chlorpyrifos (12 samples) and boscalid (9 samples) and 7 samples had acetamipride, fenazauin, lambdacyhalothrin, oxyfluorofen, and cypermethrin., and 6 samples had chlorfenapyr, metaloxyl, and pendimethalin
• The samples with the highest level of contamination were lettuce, onions, parsley, and tomatoes (100% each), followed by cucumber and thyme, (83.33% each).
• The highest percentage of contamination with pesticide (13.02%) was imidaclopride in cucumber, lettuce, onion, thyme and tomato. Also, difenaconazole was found in lettuce, onion, parsley, thyme, and tomato at a percentage of 12.43%
• Imidaclopride, Difenoconazole, and Chlorpyrifos were the pesticides with the greatest rate of violations.
• Imidaclopride was the most often found pesticide residues in cucumber samples (in 4 samples, 16%), followed by boscalid and metalaxyl (in 3 samples, 12%) each.
• Bifenthrin and imidaclopride were the pesticides that were found most frequently lettuce samples (in 6 samples, 16.67%) each, followed by acetamipride, lambdacyhalothrin, oxyfluoren, dimethomorph, and pendimethalin (8.33%) each
• Bifenthrin, imidaclopride, and cypermethrin residues were the most often found in onion samples, each being found in 6 samples (13.04%).
• Chlorpyrifos (detected in 6 samples, 60%) and Difenoconazole (detected in 3 samples, 30%) were the two pesticides whose residues were found in parsley samples the most often
• Difenoconazole (detected in 6 samples, 42.85%) and pendimethalin (detected in 3 samples, 21.43%) were the two pesticides whose residues were found in Thyme samples the most often.
• Chlorphenapyr (detected in 6 samples, 15.79%), Difenoconazole and Fenazaquin (detected in 5 samples, 13.16% each) were the three pesticides whose residues were most commonly found in tomato samples.
• Insecticides were the most prevalent category (47%), followed by Fungicides at 44%. and only 6% were herbicides
• Lambdacyhalothrin, Penconazole, Fenamiphos, Propamcarb pesticide residue from cucumber were not approved by the Agricultural Pesticide Committee (APC) for use on these commodities. Also, Lambdacyhalothrin,and Ethiofencarb), (Flusilazole, and Penconazole) pesticide residues from onion, and tomato respectively were not approved.
• The most contaminated cucumber, lettuce, onion and tomatoes samples were found in the Anabta village market. While the lowest contaminated cucumber, lettuce, onion, and tomatoes samples were found in the Tulkarm city market. Regarding parsley, and thyme, the most contaminated samples were from Tulkarm camp market.
• Types of detected pesticides residues in terms of its function, the most frequent types of pesticide residues were insecticides (47%) and fungicides (44%), and only 6% were herbicides. In addition, 3% not listed.
• 75% of detected pesticide residues were contaminated at levels higher than the MRLs set by the EU Pesticides Database and 24.78%, were higher than the MRL set by Codex Alimentarius.
3- (ADI), and Hazard risk index (HRI)
• The consumption of pesticide residues in cucumber, parsley, thyme and tomato samples did not surpass the ADI. Intake of Lambdacyhalothrin pesticide residue exceeded the ADI in lettuce sample, the hazard index for Lambdacyhalothrin was 8.24 of the ADI. The Intake of difenoconazole and imidaclopride pesticides residues exceeded the ADI in onion sample. The hazard index for difenoconazole was 3.825 of the ADI, whereas the index for imidaclopride was 9.967 of the ADI.
6.2. Conclusions:
• Pesticide residues were detected in 94.4% of the vegetable samples.
• The most highly contaminated commodities were found to be lettuce, onions, parsley, and tomatoes (100%), followed by cucumber and thyme, (83.33% each).
• The number of detected pesticides in all vegetable samples were 33 compounds.
• The most common pesticide was imidaclopride in cucumber, lettuce, onion, thyme and tomato. Also, difenaconazole was found in lettuce, onion, parsley, thyme, and tomato
• Imidaclopride, Difenoconazole, and Chlorpyrifos were the pesticides with the greatest rate of violations.
• Lambdacyhalothrin, Penconazole, Fenamiphos, Propamcarb detected pesticide residue from cucumber and Lambdacyhalothrin, and Ethiofencarb), (Flusilazole, and Penconazole) pesticide residues from onion, and tomato respectively were not approved by the Agricultural Pesticide Committee (APC) for use on these commodities.
• The most frequent types of pesticide residues were insecticides followed by fungicides and to a less extent herbicides.
• 75% of the detectable pesticide residues, were at levels higher than the MRLs set by the EU Pesticides Database, and 24.78%, were higher than the MRL set by Codex Alimentarius.
• The consumption of pesticide residues in cucumber, parsley, thyme and tomato samples did not surpass the ADI.
• Intake of Lambdacyhalothrin pesticide residue exceeded the ADI in lettuce sample, and its hazard index was 8.24 of the ADI. Also, the Intake of difenoconazole and imidaclopride pesticides residues in onion sample exceeded the ADI with a hazard index 3.825 of the ADI, and 9.967 of the ADI. This indicate that, there is a potential risk of the consumption of such contaminated vegetables on human’s health.
• The determination of pesticide residue in ‘food’ is important in environmental monitoring for the prevention, control and reduction of pollution as well as for occupational health, legal decisions and epidemiological studies.
6.3. Recommendation:
• To create and update a data base by which the future plans for pest management and consumer safety against indiscriminate pesticide-related exposure may be adopted, monitoring programs for pesticide residues in all food items should be maintained.
• Corrective action must be taken in the Good Agricultural Practice for vegetables, to maintain residues below the permissible limits.
• Educating farmers on safe and responsible pesticide usage and promoting the use of non-chemical pest control methods like biological control.
• It is important to ensure that pesticide application guidelines are followed.
• To alleviate the frightening situation in Palestine, several pesticide classes such as insecticides, fungicides, and preservatives should be thoroughly researched. Furthermore, the unauthorized use of restricted compounds, as well as their persistent nature, is a big problem that should be addressed and treated with caution.
• There is a need to raise awareness among the public so that customers are aware of the scientific methods being used to decrease the contamination of agricultural goods with potentially ingestible fresh pesticides. For instance, it has been shown that (washing, boiling, and peeling) minimize pesticide residues.
• As most of these vegetables are consumed raw, household processing, including washing, peeling, and cooking, is necessary to reduce the amount of pesticide residues in them.
• Further research on the pesticide residues in other food categories, is required.