Organophosphate and carbamate pesticide residues and accompanying risks in commonly consumed vegetables in Kenya

The current study was conducted to assess the levels of organophosphates and carbamates in vegetables in Kenya and to examine potential consumer health risks. A total of 90 samples were analysed by liquid chromatography/high-resolution tandem mass spectrometry. Residues of acephate, chlorpyrifos, methamidophos, omethoate and profenofos were found in 22% of the samples, ranging from 10 to 1343 μg/kg. The EU MRL was exceeded in 21%, 10%, 8% and 22% of the samples of French beans, kales, spinach and tomatoes, respectively. Chlorpyrifos in spinach had an acute HQ of 3.3 and 2.2 for children and adults, respectively, implying that potential health risks with respect to acute dietary exposure cannot be excluded. For chronic dietary exposure, all chronic HQs were below 1. The HI for the pesticides was 0.54 and 0.34 for children and adults. Routine monitoring of OPs and carbamates in vegetables is recommended to minimise consumer's health risks.

Determination of Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate: Collaborative Study

A collaborative study was conducted to determine multiple pesticide residues in fruits and vegetables using a quick, simple, inexpensive, and effective sample preparation method followed by concurrent analysis with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). For short, the method is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged, and safe. Twenty representative pesticides were fortified in 3 matrixes (grapes, lettuces, and oranges) at 3 duplicate levels unknown to the collaborators ranging from 10 to 1000 ng/g. Additionally, 8 incurred pesticide residues were determined. Thirteen laboratories from 7 countries provided results in the study, and a variety of different instruments were used by collaborators. The QuEChERS procedure simply entails 3 main steps: (1) a 15 g homogenized sample is weighed into a 50 mL centrifuge tube to which 15 mL acetonitrile containing 1 HOAc is added along with 6 g MgSO4 and 1.5 g NaOAc, and the tube is shaken and centrifuged; (2) a portion of the extract is mixed with 3 + 1 (w/w) MgSO4primary secondary amine sorbent (200 mg/mL extract) and centrifuged; and (3) the final extract is analyzed by GC/MS and LC/MS/MS. To detect residues <10 ng/g in GC/MS, large-volume injection of 8 L is typically needed, or the extract can be concentrated to 4 g/mL in toluene, in which case 2 L splitless injection is used. In the study, the averaged results for data from 713 laboratories (not using internal standardization) for the 18 blind duplicates at the 9 spiking levels in the 3 matrixes are as follows [%recovery and reproducibility relative standard deviation (RSDR, %)]: atrazine, 92 (18); azoxystrobin, 93 (15); bifenthrin, 90 (16); carbaryl, 96 (20); chlorothalonil, 70 (34); chlorpyrifos, 89 (25); cyprodinil, 89 (19); o, p-DDD, 89 (18); dichlorvos, 82 (21); endosulfan sulfate, 80 (27); imazalil, 77 (33); imidacloprid, 96 (16); linuron, 89 (19);methamidophos, 87 (17); methomyl, 96 (17); procymidone, 91 (20); pymetrozine, 69 (19); tebuconazole, 89 (15); tolylfluanid (in grapes and oranges), 68 (33); and trifluralin, 85 (20). For incurred pesticides, kresoxim-methyl (9.2 3.2 ng/g) and cyprodinil (112 18) were found in the grapes; permethrins (112 41), -cyhalothrin (58 11), and imidacloprid (12 2) were determined in the lettuces; and ethion (198 36), thiabendazole (53 8), and imazalil (13 4) were determined in the oranges. Chlorpyrifosmethyl (200 ng/g) was used as a quality control standard added during sample homogenization and yielded 86% recovery and 19% RSDR. Intralaboratory repeatabilities for the method averaged 9.8% RSD for all analytes. The results demonstrate that the method is fit-for- purpose to monitor many pesticide residues in fruits and vegetables, and the Study Director recommends that it be adopted Official First Action.

Hair as a matrix to evaluate cumulative and aggregate exposure to pesticides in winegrowers

INTRODUCTION

Vineyard is a crop where a large number of pesticides are applied; exposure to pesticides may occur in farmers and the general population living close to the treated area. This work aimed to investigate hair as a matrix for the assessment of cumulative and aggregate exposure to pesticides in potentially exposed individuals.

METHODS

Twenty agricultural workers (AW), 4 agricultural worker relatives (AR), and 5 research staff members (RS) were involved in the study. Hair samples were collected before and after the application season (PRE- and POST-EXP samples) to obtain 18 paired samples. Records with the name and the quantity of applied pesticides were obtained; twenty-seven pesticides were measured in hair by solvent extraction and LC-MS/MS.

RESULTS

During the study season, AW applied 14 different pesticides with median amount ranging from 12 to 7200 g. The most popular pesticides were dimethomorph, penconazole, cyazofamid, fenamidone and quinoxyfen, applied from 94 to 69% of AW. In AW, in PRE-EXP samples the majority of used pesticides was detectable (with detection rates from 6 to 88%), with median concentrations of few pg/mg hair; in the POST-EXP samples the frequency of detected values increased (from 25 to 100%), with median concentrations up to two orders of magnitude higher. In AR, most pesticides were quantifiable only in POST-EXP samples and with lower concentration in comparison with AW; in RS, in both PRE- and POST-EXP samples only a few pesticides were quantifiable with very low levels. In AW, a linear correlation (r = 0.682 on log-transformed data, p < 0.01) was found between the total amounts of applied pesticides during the season and their concentration in hair.

CONCLUSION

The study shows that the majority of assessed pesticides was incorporated into hair of AW and AR. The increased frequency of detection and level at the end of the season and the correlation between pesticide in hair and the amount of applied pesticides, reinforce the use of hair for quantitative biomonitoring of cumulative exposure to pesticides.

Fate of enniatins and deoxynivalenol during pasta cooking

The fate of deoxynivalenol and enniatins was studied during cooking of commercially available dry pasta in the Netherlands in 2014. Five samples containing relatively high levels of deoxynivalenol and/or enniatins were selected for the cooking experiment. Cooking was performed in duplicate on different days, under standardised conditions, simulating house-hold preparation. Samples were extracted with a mixture of acetonitrile/water followed by salt-induced partitioning. The extracts were analysed by LC-MS/MS. The method limits of detection were 8μg/kg for deoxynivalenol, 10μg/kg for enniatin A1 and 5μg/kg for enniatins A, B and B1. During the cooking of the five dry pasta samples, 60% of the deoxynivalenol and 83-100% of the enniatins were retained in the cooked pasta. It is recommended to study food processing fate of mycotoxins through naturally contaminated materials (incurred materials).

Decay characteristics and erosion-related transport of glyphosate in Chinese loess soil under field conditions

The decay characteristics and erosion-related transport of glyphosate and aminomethylphosphonic acid (AMPA) were monitored for 35 d at different slope gradients and rates of application in plots with loess soil on the Loess Plateau, China. The initial glyphosate decayed rapidly (half-life of 3.5d) in the upper 2 cm of soil following a first-order rate of decay. AMPA content in the 0-2 cm soil layer correspondingly peaked 3d after glyphosate application and then gradually decreased. The residues of glyphosate and AMPA decreased significantly with soil depth (p<0.05) independently of the slope inclination and application rate. About 0.36% of the glyphosate initially applied was transported from plots after one erosive rain 2d after the application. Glyphosate and AMPA concentrations in runoff were low while the contents in the sediment were much higher than in the upper 2 cm of the soil.

CAPSULE

Although the rate of glyphosate decay is rapid in Chinese loess soil, the risks of glyphosate and AMPA need to be taken into account especially in the area with highly erosive rainfall.

Short-term transport of glyphosate with erosion in Chinese loess soil--a flume experiment

Repeated applications of glyphosate may contaminate the soil and water and threaten their quality both within the environmental system and beyond it through water erosion related processes and leaching. In this study, we focused on the transport of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) related to soil erosion at two slope gradients (10 and 20°), two rates of pesticide with a formulation of glyphosate (Roundup®) application (360 and 720 mg m(-2)), and a rain intensity of 1.0 mm min(-1) for 1 h on bare soil in hydraulic flumes. Runoff and erosion rate were significantly different within slope gradients (p<0.05) while suspended load concentration was relatively constant after 15 min of rainfall. The glyphosate and AMPA concentration in the runoff and suspended load gradually decreased. Significant power and exponent function relationship were observed between rainfall duration and the concentration of glyphosate and AMPA (p<0.01) in runoff and suspended load, respectively. Meanwhile, glyphosate and AMPA content in the eroded material depended more on the initial rate of application than on the slope gradients. The transport rate of glyphosate by runoff and suspended load was approximately 14% of the applied amount, and the chemicals were mainly transported in the suspended load. The glyphosate and AMPA content in the flume soil at the end of the experiment decreased significantly with depth (p<0.05), and approximately 72, 2, and 3% of the applied glyphosate (including AMPA) remained in the 0-2, 2-5, and 5-10 cm soil layers, respectively. The risk of contamination in deep soil and the groundwater was thus low, but 5% of the initial application did reach the 2-10 cm soil layer. The risk of contamination of surface water through runoff and sedimentation, however, can be considerable, especially in regions where rain-induced soil erosion is common.

Skin dose measurements on patients for diagnostic and interventional neuroradiology: a multicentre study

The present study reports on the skin dose measurements on patients undergoing diagnostic and interventional neuroradiology procedures. Grids of thermoluminescence dosemeters were attached on the head of the patient. The exposure parameters of the X-ray systems and the clinical procedures were fully documented. While for the diagnostic procedure, the dose threshold of 2 Gy for deterministic effects was not reached, this situation was much different for the embolisations. For angiography of the carotid arteries, no skin doses were measured >320 mGy. For the cerebral embolisations, maximum skin doses up to 5.4 Gy were measured. Doses to the patients varied largely between different hospitals and within the same hospital for similar procedures. On the one hand, the complexity of the pathology for interventional procedures was responsible for the large variability in dose. On the other hand, large differences in clinical protocol and technical parameters of the X-ray systems, explaining the dose variations, were also observed. A correlation was found between the maximum skin dose measured on a patient and the total dose-area product (DAP) value for cerebral embolisations. This correlation makes it possible to estimate the maximum skin dose from these DAP values and to determine a trigger level. In conclusion, management of patient doses in interventional radiology requires training, specialisation and well-documented procedure guidelines.

Technical quality control in mammography screening: first results in Belgium

In this paper the first results of the application in Belgium of the European protocol for the technical quality control of mammography screening are presented. Twelve mammography screening units were submitted to an acceptance test: one fourth complied with the criteria after a second visit. A daily quality control procedure has been run since eighteen months. The most important detected problems are given and discussed. The European Commission, in the framework of "Europe Against Cancer", recently published the "European Guidelines for Quality Assurance in Mammography Screening" (1). In another contribution (2), a brief overview of the important appendix "European Protocol for the Quality Control of the Technical Aspects of Mammography Screening" was given. In this paper the first results for the application of this protocol in Belgium are presented.

Quality control in mammography: practical implications

The programme "Europe against cancer" stimulated, among other activities, breast screening activities in the member states. From the beginning, it was clear that a rigorous and efficient approach required the highest possible quality of the three major components of a breast screening programme: the medical performance (correct positioning, training of the medical staff, double reading of the mammograms and feedback from the pathologist and the epidemiologist), the organisation (attendance rate, data base) and the quality of the imaging process (compliance of the image quality and the breast dose with the CEC document of 1990). The first part of this paper will be limited to the latter component and the second part to the subject of correct positioning of the breast.

[A case of food poisoning caused by C. perfringens]

A case of food borne infection among a hundred inhabitants of a home for the old aged, caused by Clostridium perfringens (Clostridium welchii) following consumption of a filled veal roll is reported.

[Staphylococcal enterotoxemia following consumption of a pork fricandeau]

A case of food poisoning in a 45-year-old man, caused by enterotoxin C produced by Staphylococcus aureus following the consumption of porc-fricandeau is reported. The findings are discussed on the basis of data from the literature on abscesses in slaughtered animals.

[The occurrence of dapsone residues following a one-time oral, intramuscular and intramammary application in healthy dairy cows]

Dapsone is frequently used as a bacteriostatic drug in the treatment of mastitis, endometritis and footrot (necrotic pododermatitis). The farmer usually obtains this drug by 'non-ethical' channels. A regular scheme of checking the milk for residues of sulphonamides will be introduced in 1986. The sensitivity of the test is approximately 25 ppb for Dapsone. This will result in lower milk price in the case of positive tests. In healthy animals, it is shown that intramuscular treatment with 35 grammes (+/- 70 mg/kg-1 body weight) of Dapsone results in residues of Dapsone and its metabolite monoacetyldapsone above this detection level for more than 6 1/2 days. Within 5 days after oral treatment with 48.75 grammes (+/- 100 mg/kg-1 body weight) and 2 1/2 days after single intramammary treatment with 0.8 grammes, the concentrations of residues detected dropped below 25 ppb. The other well-known metabolite diacetyldapsone was only present in detectable quantities in the first milkings after oral treatment.

[The occurrence of sulfa residues in unpasteurized farm milk]

The results of studies in 1984 and 1985 on the incidence of residues of sulphonamides in raw tank milk showed that, from 2 to 11 per cent milk was contaminated with Dapsone in the Netherlands. In 1984 sulphadimidine was found to be present in approximately six per cent of the samples of tank milk. In 1985, residues of Dapsone were detected, in approximately six per cent of the milk destined for consumption.

[Prevention of food-borne diseases in the Netherlands. Are we on the right course?]

It is estimated that in the Netherlands several hundreds of thousands of patients are affected with food-borne diseases or poisoning each year. Though the symptoms are usually mild and mortality is low, the financial impact on society is enormous. The consumer is hardly aware of this fact and the--substantial--government efforts to achieve prevention are not very effective. In view of the present state of science, it should be possible to ensure the consumer of safe food on the market, which may be eaten without any risk after sound preparation. The origin, magnitude and effects on society of this complex problem are studied in the present review. An attempt is made to evaluate the possibilities of reducing the morbidity of food-borne diseases, regarded by the World Health Organization as the most important problem in public health after diseases of the respiratory tract in the coming decades. Particular attention is paid to the role to be played by the authorities in these efforts to reduce morbidity.