Ioannis Tsakiris

Three-year study of fenthion and dimethoate pesticides in olive oil from organic and conventional cultivation

Residues of fenthion and dimethoate pesticides were determined in organic and conventional olive oils by liquid-liquid and solid-phase extractions with subsequent gas chromatography and mass spectrometric analysis. The olive oil samples were collected from Crete during 1997–99. The average concentrations of fenthion in conventional olive oils were 0.1222, 0.145 and 0.1702 mg kg−1, and for dimethoate were 0.0226, 0.0264 and 0.0271 mg kg−1 for 1997, 1998 and 1999, respectively. The average concentrations of fenthion in organic olive oils were 0.0215, 0.0099 and 0.0035 mg kg−1 for 1997, 1998 and 1999, while for dimethoate they were 0.0098, 0.0038 and 0.0010 mg kg−1, respectively. All the olive oils contained residue levels lower than the maximum resi-due levels according to the FAO/WHOCodex Alimentarius. The organic olive oil contained significantly lower concentrations of the two pesticides. The levels of fenthion and dimethoate in organic olive oils exhibited a decreasing trend following the implementation of the new cultivation method. We propose procedures that should be established in the organic cultivation in order to maximize its effectiveness.

Risk assessment scenarios of children’s exposure to aflatoxin M1 residues in different milk types from the Greek market

Occurrence of aflatoxin M1 (AFM1) was determined in 196 milk samples (conventional, organic and kids milk) from the Greek market during November 2009 to June 2010. AFM1 content was analyzed using an Enzyme-Linked Immunosorbent Assay (ELISA) commercial kit. Aflatoxin M1 was detected in 46.5% of the samples. 46.5% of the samples were found positive for AFM1. The most frequent range of detection was between 5 and 10 ng/l. Based on the EU regulation only 2 milk samples presented AFM1 levels higher than the maximum residue limits. Two different scenarios were used for the determination of hazard index: (a) scenario 1 using only positive (detected AFM1) samples and (b) scenario 2 when missing values where imputed with Limit of Detection (LOD) divided by 2. Significant statistical differences between different milk categories were presented only when the results were imputed with LOD/2 values. Exposure assessment scenarios were developed for ages 1, 3, 5, 7 and 12 and their respective estimated weights and daily milk consumption. Under the worst-case scenario all milk types presented a Hazard Index (HI) less than one. The highest HI values appear in the ages of 1-3.

Monitoring of pesticide residues in fresh peaches produced under conventional and integrated crop management cultivation

The frequency and severity of crop protection product (pesticide) contamination of peaches grown conventionally were compared with those of peaches grown by integrated crop management (ICM). The peach samples (n = 150) were collected preharvest (June–August 2001) from both conventional (n = 55) and ICM (n = 95) cultivations from the Pella and Imathia districts of Macedonia, Northern Greece. The residue levels of selected insecticides, fungicides and acaricides in peach samples were determined by gas chromatography-mass spectrometry following solid-phase extraction. The concentrations of all detected pesticides were lower than the maximum residue limits (MRLs) in all peach samples grown with the ICM system (p<0.001). However, chlorpyrifos residues at levels higher than the MRLs were detected in four peach samples (i.e. 7% of the total samples) grown by the conventional system. Comparing the results for both cultivation methods with the reported average percentage (3.6%) of fruit samples with pesticide residues above the MRLs (European Union report for Greece in 2001), it was concluded that the initial implementation of the ICM in Greece was successful. The present study indicates that ICM cultivation has a higher efficiency in terms of product safety and quality. Furthermore, the results suggest that the application of conventional cultivation requires continuous monitoring of various crop protection product levels.

Risk assessment for children exposed to DDT residues in various milk types from the Greek market.

The occurrence of residues of DDT and its metabolites was monitored in 196 cow milk samples of various pasteurized commercial types collected from the Greek market. Residue levels were determined by GC-MS analysis. In 97.4% of the samples at least one DDT isomer or one of the DDT metabolites was detected, in levels not exceeding the maximum permitted residue level by the EU. Hazard Index for both carcinogenic and non-carcinogenic effects was estimated under two assumptions: a) using DDT concentrations from positive samples and b) imputing LOD/2 as an arbitrary concentration for negative samples. No statistically significant differences in detected or summed residue (p > 0.05) concentrations between different milk types were observed, with the exception of specific metabolites of DDT in some milk types. Exposure assessment scenarios were developed for children aged 1, 3, 5, 7 and 12 years old based on estimated body weights and daily milk consumption. Hazard Indices for non-carcinogenic effects were below 0.109 covering also carcinogenic effects according to WHO approach. The cancer risk values for carcinogenic effects according to the US EPA Cancer Benchmark Concentration approach, ranged from 0.4 to 18. For both effects the highest values were calculated for the 1- to 3-year-old age groups.

A Risk Assessment Study of Greek Population Dietary Chronic Exposure to Pesticide Residues in Fruits, Vegetables and Olive Oil

Ioannis N. Tsakiris3, Maria Toutoudaki1, Manos Kokkinakis2, Mitlianga Paraskevi3, and Aristides M. Tsatsakis1, 1Laboratory of Toxicology, Department of Medicine, University of Crete, Voutes 71409, Heraklion 2Technological Education Institute (T.E.I) of Crete, Food Quality Laboratory, K. Palama and I. Kakridi Str., 722 00 Ierapetra, Crete 3TEI of Western Macedonia, Florina Branch, Department of Agricultural Products Management and Quality Control, Terma Kontopoulou 53100 Florina Greece

Bisphenol A in soft drinks and canned foods and data evaluation

ABSTRACT Bisphenol A (BPA) is one of the most common industrial chemicals and known to exert endocrine disruption activity. The aim of this study was the quantification of BPA in food stuffs on the Greek market. The applied liquid chromatography-mass spectrometry method was validated for linearity, limit of quantification, accuracy, precision and recovery. About 41.7% of the canned solid phase samples, 25.0% of the canned liquid phase samples and 43.8% of the soft drinks were positive. Mean BPA concentrations (range) were 33.4 ± 4.4 ng/g (4.90 ± 0.64–66.0 ± 8.6 ng/g) in canned solid phase, 2.70 ± 0.08 ng/ml (1.90 ± 0.06–3.50 ± 0.11 ng/ml) in canned liquid phase and 2.30 ± 0.18 ng/ml (0.40 ± 0.03–10.2 ± 0.8 ng/ml) in soft drinks. The results of this study are comparable with those reported in the literature according to which higher concentrations of BPA were detected in the solid fraction of canned food compared to their liquid fraction.

Correlation between Plant Growth Regulator Release Rate and Bioactivity for the Series of Newly Synthesized Phytoactive Polymers

Phytoactive polymers are high molecular weight systems in which a plant growth regulator (PGR) unit is attached to the polymeric chain by a hydrolyzable chemical bond. The release rate of the PGR is linked to the biological activity of the phytoactive polymer and can be controlled by properties inherent in the whole macromolecular system. In this study the correlation of biological activity and plant growth regulator hydrolytic release rate was investigated for the series of newly synthesized 2,4-dichlorophenoxyacetic acid (2,4-D) polymeric esters. The polymers synthesized differ in their molecular weight, side group structure, and 2,4-D residue content. The influence of these polymer characteristics on the 2,4-D hydrolytic release was investigated, and it was demonstrated that hydrolysis rate substantially depends on the polymer molecular weight, side group structure, and 2,4-D residue content. It was also demonstrated that phytoactive polymer bioactivity depends on the hydrolysis rate of the polymers, and in dependence of this parameter can provide stimulating or inhibiting activity. Biological activity was illustrated by the elongation of wheat and barley coleoptiles.

Fenthion, Dimethoate and Other Pesticides in Olive Oils of Organic and Conventional Cultivation

Publisher Summary The most common organophosphorous plant protection products are dimethoate and fenthion. Drift is always a potential danger for organic cultivation. In this cultivation system, protection measures are always taken so as to avoid drift from neighboring fields. Despite this, however, it is practically impossible to eliminate the effect of this factor. The hypothesis that the residues in organic oils arise from the contamination of the olives because of drift is usually true, yet of low importance. In drift cases, data in relation to the existence of neighboring cultivations, the local application, common and frequent practice and knowledge of the weather conditions in the area, are essential in order to conclude for residues origin. This chapter presents the status of pesticide residues in olive oil, focusing on fenthion and dimethoate residue data from olive oil samples from organic cultivation and conventional cultivation. The data used are based on the results of our laboratory during the years 1999–2001 and 2005; on the results reported by certification organizations during the period 2006–2008; and on the results cited in recent and current bibliography during the period 2000–2008. These results are used so as to assess the relationship between the quality of organic and conventional olive oil and the levels of selected pesticide residues. Assessment of the factors that affect the levels of pesticide residues in olive oil during the cultivation and production procedures is a further objective of this chapter.

Risk assessment of exposure to aflatoxin B1 and ochratoxin A through consumption of different Pistachio ( Pistacia vera L.) cultivars collected from four geographical regions of Iran

Iran is one of the main suppliers of pistachio for the European market accounting for over 90% of its demands; hence, efficient analytical methods are required for detection of mycotoxins contamination in pistachio kernels before exporting them. In this study, aflatoxin B1 (AFB1) and ochratoxin A (OTA) levels in five pistachio cultivars collected from four sites of Iran, were measured by HPLC. Based on the results, risk assessment for AFB1 and OTA residues was done. The highest mean concentrations of AFB1 and OTA were found in Ahmad-aghaei (4.33 and 2.19 ng/g, respectively) and Akbari (4.08 and 1.943 ng/g, respectively) cultivars from Rafsanjan, Iran. Even the highest concentrations of AFB1 and OTA in analyzed samples were lower than the corresponding maximum limits set by EU authorities. The hazard index (HI) value for consumers of Iranian pistachio is below one. It could be concluded that consumption of pistachio cultivated in these regions poses no health risk of mycotoxins exposure.