Monitoring and Minimizing Pollutants of Some Certain Vegetables by Using Different Methods of Cooking

Abstract

In Egypt, exportation of fruits and vegetables was affected with the level of contamination by pesticides residues .Organochlorine, orgnophosphrous and organonitrogen pesticides were the main contaminants found in these commodities. According, monitoring programs of pesticide residues in the fruits and vegetables in the governorates in which these commodities are cultivated and at exportation ports are required to generate a flow of data that serves in following up the regulation of pesticides use and evaluates the situation of fruits and vegetables contamination with pesticides residues in order to compare them with the corresponding FAO/WHO acceptable daily intake for risk assessment purposes and enabling the decision –makers to take the convenient corrective actions to minimize health hazards and adverse impact of pesticide use.Oraganophosphorus compounds are among the most acute toxic pesticides on the market worldwide, and their registration is being phased out or has been canceled in many countries. On the other hand agriculture products such vegetables and fruits are important components of the human diet as these are sources of vitamins and minerals. But, these commodities could also be a potential source of harmful and toxic pesticides. Thus, food safety has become a major public concern worldwide. Heavy metals may contaminate different plants causing serious health hazards such as injury of kidney, symptoms of chronic toxicity, renal failure and liver damage. The source of environmental pollution with toxic metals are quite varied, ranging from industrial and traffic emissions to the use of purification mud and agricultural expedients, such as cadmium-containing dung, organic mercury fungicides and the insecticide lead arsenate. Therefore, the aim of this study was to monitor the residue levels of pesticides and heavy metals in some products (such as strawberry and green beans. A total number 4079 samples of green beans (i.e.2542) and strawberry (i.e. 1537) were collected from local markets in Egyptian governorates (i.e., Cairo, Giza, Kalyobiya, Gharbiya, Sharkiya, Fayoum, Minufiya and Ismailia) during the period from 2008 to 2010. So, the objective of the present study was to find out the extent and magnitude of certain group of pesticides residues in strawberry and green beans. Also, to obtain data on how typical home-processing practices affect pesticide residues in the commodities under the investigation. The data would help in assessing the risk of human exposure to pesticides. A multi residue method based on the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) sample preparation method and gas chromatography coupled to mass spectrometry (GC-MS/MS) and liquid chromatography coupled to mass spectrometry (LC-MS/MS) were adopted for the analysis of pesticides and the microwave digestion is especially recommended for determination of heavy metals in samples by using atomic absorption spectrometry. The potential health risk associated with intakes of each violated pesticide residue on each crop was estimated as well. The results obtained can be summarized as follows: 1. Monitoring of pesticides residues in green beans, and strawberry 1.1. Monitoring of pesticide residues in the Green beans: The results indicated that 60.4% of the total number of all green beans samples collected during the period from 2008 to 2010 analyzed was free from any detectable pesticide residues. However, 39.6% contained detectable residues, of which 4.1% contained residues that exceeded maximum residue limits (MRLs), which could pose adverse effects on health of consumers. The highest contamination percentage (i.e. 44.1%) was recorded in the samples collected during the year 2010, followed by that collected during the year 2008 (i.e. 42.2%). However, the lowest contamination % (i.e. 31.4%) was recorded in the year 2009. While, the highest violation percentage (4.3%) recorded in the contaminated samples collected during 2008, followed by that collected during the year 2009 (4.2%). While, the lowest violation percentage (i.e. 3.8%) was recorded in the year 2010. The percentage no. of samples contained 2 and 3 or more pesticide residues elevated from year 2008 to year 2010, where the percentage numbers are 11.5%, 13.3%, and 24.8% in years 2008, 2009, and 2010, respectively. On the other hand, in 2008, 2009 and 2010 the percentage no. of samples contained 3 or more pesticides residues were 5.1%, 6.2%, and 10.2%, respectively. However, the percentage of samples contained 2 pesticide residues were 6.4%, 7.1%, and 14.6%, respectively. The percentage of samples contained one pesticide residues decreased from the year 2008 to 2009, where the percentage was 30.7% in the year 2008, which decreased to 18.2% in the year 2009. However, in the year 2010 the % showed slight increase in the value to 19.4%. The most contaminated samples in each year according to the number of detections (of pesticide residues) recorded in year 2009, where the number of the detected pesticides were 71 followed by that recorded in year 2010 (70 detected pesticides). However, the lowest number of the recorded pesticides in year 2008 (41 detected pesticides). While, the most contaminated samples in each year according to the number of contaminated samples with one or more pesticides are in year 2010 having 61.5% of their samples contaminated, followed by that recorded in year 2009 (55.2%) and then that recorded in 2008 (39.3%).