الفهرس 
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Abstract
The current study was accomplished to provide strong pattern of information on the contamination levels of pesticide residues, calculated exposure, and the potential health risks in orange, banana, and guava samples collected from five markets in Assiut Governorate in Egypt, i.e. El Badari, Assiut city, Manfalut, El Qusiya, and Dairut in December 2019 using QuEChERS method and LC-MS/MS instrument. Results procured throughout this work could be summarized as follows:
I. Monitoring of pesticide residues in orange samples
1- The most frequent pesticides are pyridaben (Assiut city, Manfalut and Dairut markets), acetamiprid (El Badari and Manfalut), flusilazole (El Badari and El Qusiya), and fenamiphos (Assiut city and Manfalut).
2- Flusilazole is considered the only pesticide residue that exceeded the MRL level in two cities (El Badari and El Qusiya) (0.03 and 0.02 mg/kg, respectively, whereas the MRL is 0.01 mg/kg).
3- Based on the HRI values, none of the pesticide residues found in the selected markets is considered health risk issue in orange samples.
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II. Monitoring of pesticide residues in banana samples
1- The most frequent pesticides are oxamyl (El Badari, Assiut city, Manfalut, El Qusiya and Dairut markets), fosthiazate (El Badari, Manfalut and Dairut markets), azoxystrobin (Assiut city, El Qusiya, and Dairut markets), ethoprofos (Assiut city, El Qusiya and Dairut markets) and cadusafos (El Badari and El Qusiya markets).
2- Four pesticides exceeded the MRLs (cadusafos, ethoprofos, tetraconazole and carbendazim) in El Badari and Assiut city (0.03, 0.1, 0.04 and 0.54 mg/kg, respectively, whereas the MRLs were 0.01, 0.02, 0.02 and 0.1 mg/kg). Cadusafos and ethoprofos belong to organophosphorus pesticides, tetraconazole belongs to triazoles and carbendazim belongs to benzimidazoles.
3- None of HRI values were found to be greater than one. Thus, none of the pesticide residues found in selected markets are considered health risk issue in banana samples.
III. Monitoring of pesticide residues in guava samples
1- The Most frequent pesticides are oxamyl (El Badari, Assiut city, Manfalut, and El Qusiya markets), followed by dimethoate (El Badari, Manfalut, and El Qusiya markets), and difenoconazole (Assiut city and Manfalut markets).
2- Dimethoate is considered the pesticide residue that surpassed the MRL level in guava samples found in El Qusiya market.
3- According to HRI values, none of the pesticide residues observed in selected markets is considered health risk issue in guava samples.
Totally, 29 pesticide residues were found in 5 markets in Assiut Governorate (11 fungicides, 7 insecticides, 6 acaricides, and 5 nematicides). The most frequent one is oxamyl (9 times) in the five studied cities, followed by fenamiphos, dimethoate, fenpyroximate and azoxystrobin (4 times for each pesticide), then imidacloprid, pyridaben, difenoconazole, ethoprofos, fosthiazate and tetraconazole (three times for each pesticide). However, organophosphorus pesticides were the most prevalent, they are represented in 6 pesticides, followed by triazoles (4 pesticides), three neonicotinoids and only 2 organochlorine pesticides, two of strobilurins, one of pyrethroids, and 11 other pesticides belong to different chemical classes.
In conclusion, pesticide residues were found in the collected samples from the selected locations in Assiut Governorate. However, certain pesticide residues exceeded the MRL levels. Thus, the application of pesticides in fields and greenhouses must be controlled and their residue levels must be analyzed using the multi-residue method before distribution and consumption of such fruits using highly regulated pesticide residue control programs. With this regard, our findings, revealed that the multi-residue method with LC-MS/MS might perfectly detect a large number of pesticide residues simultaneously with high accuracy. Furthermore, it is recommended that this method be generalized for all fruits in order to assess pesticide residue levels before reaching the markets. Consequently, regular pesticide residue analysis program is recommended to monitor pesticide residues in fruit samples to retain the food safety especially in Upper Egypt.