Naglaa M. Loutfy

Residues of organochlorine and synthetic pyrethroid pesticides in honey, an indicator of ambient environment, a pilot study

Samples of honey were screened to monitor residues of organochlorine and pyrethroid pesticides. The study meant to examine the quality of honey, and to use honey as a bioindicator of environmental contamination. Residue levels were determined by gas chromatography (GC-μECD). Samples had a wide spectrum of organochlorine and synthetic pyrethroids pesticides, with hexachlorobenzene (HCB) as the most frequently detected organochlorine, followed by permethrin, heptachlor epoxide. Only one sample had a concentration of γ-HCH higher than maximum residue limit of honey (0.01 mg kg(-1)). Residues of organochlorines detected, indicate the presence of some fresh supplies, despite the ban imposed on their use. The study confirmed that honey bee and beehive matrices could be used as gauge for monitoring environment contamination. From public health point of view, the observed levels of pesticide residues in honey do not pose a serious health risk to the consumers, but raises questions of the source of organochlorines.

Residue Levels of DDE and PCBs in the Blood Serum of Women in the Port Said Region of Egypt

An investigation was conducted to detect residues of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and polychlorinated biphenyls (PCBs) in blood serum samples collected from a cohort of fasting females attending the health insurance outpatient clinic at Port Said between July 1999 and July 2000. Females involved in the study included 43 females diagnosed with invasive adenocarcinoma of the breast, 21 female suffering benign breast disease, and 11 normal healthy females. Serum was separated and its contents of DDE and PCBs were extracted and determined, using gas chromatography, equipped with electron capture detector. Mean residues of DDE detected in the three examined groups of females were 41+/-5.2, 48+/-6.2 and 31+/-2.5ng/g for breast cancer cases, benign breast disease cases and controls, respectively, indicating some significantly less residues in blood serum of control females. While PCBs residues detected were 54+/-17, 59+/-23 and 61+/-21ng/g, for the three groups, respectively. Residues of DDE detected in all females alike in the present study are about 15 times higher than residues detected in Canada and The Netherlands.

Residues of chlorinated hydrocarbons, polycyclic aromatic hydrocarbons and polychlorinated biphenyls in some marine organisms in Lake Temsah, Suez Canal, Egypt

Lake Temsah is the end point where some municipal, agricultural and industrial wastewaters are discharged. The lake is connected to the Suez Canal where large volumes of petroleum oil are passed from producing countries in the Arab Gulf to Europe and North America. The lake is the main source of fish for the area of Ismailia and a recreational site where the tourism industry thrives. Recently, numerous complaints have been made about the level of pollution in the lake which affects to a significant extent fishing and tourism industries. In the present study, residues of some chlorinated hydrocarbon pesticides, polycyclic aromatic hydrocarbons and polychlorinated biphenyls were monitored in some of the lakes organisms. Mullet ( Mugil cephalus , usually living in the water column), crab ( Lupa pelagcus , an intertidal organism) and a bivalve ( Ruditapes decussata, a benthic sedentary organism) were selected as representatives of various strata of the lake ecosystem. Residues of an endosulfan, DDE, Dieldrin, heptachlor epoxide and Dicofol were detected. Aroclor residues were not seen. Endosulfan had the highest detected concentration of all organochlorines: concentrations were 24.1, 52.3, 124.8, and 65.6 µg kg -1 in fish skin, fish gills, fish muscles and bivalves respectively. DDE was the most frequent detected organochlorine, detected in all samples, while Dieldrin was only detected in bivalves and crab. The concentration of polycyclic aromatic hydrocarbons was lowest in fish skin, 2.7 µg kg -1 , and highest in bivalves, 48.9 µg kg -1 . Fluorine and anthracene were the most frequently detected polycyclic aromatic hydrocarbons compounds, while acenaphthene was the least detected. The highest concentrations of organochlorines and polycyclic aromatic hydrocarbons, 108 and 48.9 µg kg -1 , respectively, were detected in bivalves. Bivalves also had the widest spectrum of detected organochlorines and polycyclic aromatic hydrocarbons. All tested organisms showed a higher ability to accumulate organochlorines in comparison to polycyclic aromatic hydrocarbons. Results also showed some indications that factors other than fat content may have some influence on the accumulation of persistent contaminants in biological tissues.

Field dissipation and health hazard assessment of Fenhexamid on Egyptian grapes

Dissipation behavior and hazard assessment of the fungicide fenhexamid applied to grapes were investigated under climatic conditions in Egypt. Fenhexamid residues were extracted from grape samples with ethyl acetate. The extract was cleaned up by QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, and determined by gas chromatographic method (GC-μECD). The average recoveries ranged between 94.2% and 99.4% with associated relative standard deviation not exceeding 12%. The estimated limit of quantification for fenhexamid was 0.1 mg/kg. The field results showed that fenhexamid dissipated rapidly from grapes and had a half-life of approximately 4.21 days. Hazard assessment was evaluated by using the hazard quotient (HQ). Data showed that the HQ value was significantly less than HQ = 1. Results indicate that hazard of fenhexamid use in grape even at 1.5-fold higher than recommended dosage was negligible to humans. This study could provide guidance for safe and reasonable use of fenhexamid in grapes and prevent health problems to consumers. However, further hazard assessment studies are needed to ascertain the hazard of fenhexamid residues on grape to vulnerable groups, including children, pregnant women, and elderly consumers.

Hazard index, a tool for a long term risk assessment of pesticide residues in some commodities, a pilot study.

Samples of some vegetables were analyzed for pesticides residues using the accredited (QuEChERS) method. The method allowed the determination of 215 compounds of different pesticide chemical groups. LC-MS/MS and GC-MS/MS were used for residues quantification. In a total number of 116 samples, no pesticides residues were detected in 34 samples (29.3%), while 82 samples (70.7%) had detectable pesticide residues, with some samples exceeding the MRLs levels established by the Codex Alimentarius Commission. The hazard index (HI %), representing the long--term risk assessment was in the range of 0.01%-15.04% of the ADIs. The highest exposure was observed for ethion, followed by chlorpyifos, both of them are organophosphates, at 15.04% and 2.45% of ADI respectively. The acute (short-term) exposure was also estimated. Results showed a potential risk for children posed by 3 pesticides, meanwhile, residues of one pesticides showed potential risk to adults (>100% of ARfD). The present work is an attempt to provide a model for the use of WHO template for calculating the short term intake. This model is especially useful for developing countries where information about consumption rate is rather meager.

Dissipation kinetics of novaluron in tomato, an arid ecosystem pilot study

Novaluron, a newly introduced insecticide, is used for control of a number of field pests. However, information regarding novaluron residues and dissipation profile is limited. In this study, dissipation and residual levels of novaluron in tomato under open field conditions were investigated using high performance liquid chromatography equipped with diode array detector (HPLC-DAD) with quick, easy, cheape, effective, rugged (QuEChERS) method. The method was validated using blank samples spiked at three levels and results showed that recoveries ranged from 93% to 99%. Novaluron residues tend to dissipate following first-order rate kinetics with half-life of 2.08 days. Data demonstrated that the use of novaluron at recommended doses would not pose any hazards to consumers. The present results aid to establish the safe use of this pesticide on tomatoes, and possibly on other crops in Egypt.

Pesticide and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) residues in foodstuffs from Ismailia city, Egypt

Samples of vegetables and cereals from Egypt were screened for 113 pesticides, of which 68 were quantified, using gas chromatography-mass spectrometry (GC/MS) with limits of detection (LODs) ranging from 0.02 to 1.9 µg kg−1. In addition, the residues of 17 non-dioxin-like polychlorinated biphenyls (NDL-PCBs) were measured in samples of animal origin (meat, dairy products and seafood) using high-resolution gas chromatography (HRGC)/high-resolution mass spectroscopy (HRMS). None of the cereal samples and 72.7% of the vegetables contained any detectable levels of the pesticides. Detectable residues, not exceeding the current European Union maximum residue limits (MRLs) were found in 27.3% of vegetables. The estimated daily intake for detected pesticides was well below their corresponding acceptable daily intake (ADI), with exposure ranges between 0.002% of the ADI for profenofos and 0.2% of the ADI for lambda-cyhalothrin. The sum concentration of 17 PCBs congeners varied between 2.5 and 322 ng g−1 fat, corresponding to 1.7-216 ng g−1 fat for the seven indicator PCBs. The highest values were measured in seafood, the lowest in dairy products. Hexa-CB 153, 138 and hepta-CB180 were the congeners with the highest contribution. PCBs congener profiles found in most of the samples were consistent with the expected profile for Aroclor 1260 and 1262. PCBs’ contamination levels reported in this paper were many times lower than in developed countries, except for chicken samples. Also, the dietary intake of seven indicator PCBs due to the consumption of food of animal origin (4.84 ng kg−1 body weight day−1) from Ismailia city, Egypt, is several times lower than the intake in European Union countries.

Residue Levels, Profiles, Emission Source and Daily Intake of Polycyclic Aromatic Hydrocarbons Based on Smoked Fish Consumption, An Egyptian Pilot Study

Residue levels and spectrum of polycyclic aromatic hydrocarbons (PAHs) were determined in smoked fish, and canned smoked fish, collected from grocery shops from Cairo, Giza, Menoufya, and Ismailia governorates, Egypt. Residues of PAHs were monitored using gas liquid chromatography, equipped with a flame ionization detector. The concentrations of ∑13 PAHs in the smoked fish and the canned smoked fish ranged from 36.06–547.1 μg/kg, respectively. Benzo(a)pyrene was not detected in smoked canned fish, while its mean residues in smoked fish amounted to 1.1 μg/kg, corresponding to one fifth of the maximum tolerable limit of 5 μg/kg established by EU. The congeners profile showed that the sources of PAHs in the two brands of smoked fish are mainly petrogenic. Based on smoked fish the daily intake of 13 PAHs and benzo(a)pyrene were 45.59 μg/day and 0.092 μg/day, respectively, while for canned smoked fish the intake was fifteen times lower (3 μg/day), and the intake of benzo(a) pyrene is zero μg/day. Results showed that the consumption of smoked fish would pause some risk to consumers; meanwhile canned smoked fish showed no risk to Egyptian consumers.

Reuse of Wastewater in Mediterranean Region, Egyptian Experience

Water scarcity in the Mediterranean region is one of the most serious issues. A number of reasons are behind this situation, which include, but are not restricted to, the relatively uneven distribution of precipitation, high temperatures, increased demands for irrigation water, and impacts of tourism. Climate change is expected to aggravate the situation even more. The use of wastewater is one of the most sustainable alternatives to cope with water shortage. It would have a number of advantages that include closing the gap between supply and demand, stopping the pollution of fresh water resources, providing sound solution to water scarcity and climate change, and helping to achieve Millennium Development Goals. With Egypt, trying to cope with water shortage issues, The Ministry of Water Resources, MWRI has developed a National Water Resources Plan, with wastewater reuse as a central mechanism. At present, there are more than 200 wastewater treatment plants in the country. Urban coverage of improved sanitation gradually increased from 45% in 1993 to 56% in 2004. In contrast, rural sanitation coverage remains incredibly low at 4%. The low coverage, in combination with a sub-optimal treatment, results in some problems of water pollution and degradation of health conditions because the majority of villages and rural areas discharge their raw domestic wastewater directly into the waterways. Drainage water reuse is practiced on a very large scale. The official reuse of agricultural drainage water in irrigation amounted to 4.84 km3/year in 2001. The present aim of the Government of Egypt is to reuse up to 8 km3/year in new reclamation areas in the near future. Meanwhile, El Salam canal, one of the mega projects in Egypt is transferring a mix of fresh Nile water and wastewater to Sinai, to irrigate thousands of newly reclaimed areas.

Hazard assessment of the neonicotinoid insecticide thiamethoxam residues in tomato: a prelude to risk assessment profile

A minor modification to the QuEChERS (quick, easy, cheap, effective, rugged and safe) method was carried out for the analysis of thiamethoxam in tomato using high performance liquid chromatography equipped with a diode array detector (HPLC-DAD). The method showed a good linearity with a determination coefficient (R2) of 0.999 for the 0.02–5 mg/L concentration range. The method was validated using a blank tomato spiked at 0.05, 0.1 and 0.5 mg/kg, and the average recovery rate was 96%–99%. The limits of detection and quantification were 0.02 and 0.05 mg/kg, respectively. In this study, dissipation and residual levels of thiamethoxam in tomato under open field conditions were investigated. Thiamethoxam residues tend to dissipate following first-order rate kinetics with a half-life of 2.34 days. At harvest time, the remaining residues of thiamethoxam were below the European Union (EU) maximum residue level of 0.2 mg/kg when measured 14 days after the final application. Exposure of thiamethoxam was determined and compared to acceptable daily intake (ADI). The assessment of consumer exposure was based upon the estimated daily intake (EDI) which was compared to ADI and expressed as percentage. Based upon tomato consumption, the EDI of thiamethoxam ranged from 8.82 × 10−6 to 3.38 × 10−4 mg/kg b.w./day, which corresponds to 0.08% and 3.3% of ADI, respectively. Since the dietary exposure never exceeded 4% ADI, the tomato fruit may be considered safe for human consumption after application of the recommended dose of thiamethoxam.