Dissipation kinetics and consumer risk assessment of novaluron + lambda-cyhalothrin co-formulation in cabbage

Cabbage, one of the most popular vegetables in the world is infested by several insect-pests and diseases. Novaluron, a chitin synthesis inhibitor and lambda-cyhalothrin, a synthetic pyrethroid group insecticide are used to manage insect-pests on cabbage. The dissipation kinetics and risk assessment of combination formulation (novaluron 9.45% + lambda-cyhalothrin 1.9%) with different modes of action has not yet been investigated in cabbage. Multi-location supervised field trials were therefore, conducted in different agro-climatic regions of India for safety evaluation of the combination product. The co-formulation at the recommended (novaluron 750 g a.i. ha^-1 + lambda-cyhalothrin 750 g a.i. ha^-1) and double the recommended (novaluron 1500 g a.i. ha^-1 + lambda-cyhalothrin 1500 g a.i. ha^-1) dose was sprayed on the cabbage crop. The samples were extracted and cleaned up using a modified QuEChERS method, and the residues analyzed by GC-ECD and GC-MS. The half-life (t_1/2) varied between 1.77 and 2.51 and 2.00-3.38 days for novaluron and 1.36-2.24 and 1.69-3.82 days for lambda-cyhalothrin in cabbage at respective doses. The Food Safety and Standards Authority of India (FSSAI) has set the MRL of 0.7 mg kg^-1 for novaluron at PHI of 5 days, and no MRL is set for lambda-cyhalothrin in cabbage. On the basis of OECD MRL calculator, the MRLs of 0.6 and 1.5 mg kg^-1 for novaluron and lambda-cyhalothrin, respectively were calculated at the respective doses at PHI of 3 days. Hazard quotient (HQ) <1, theoretical maximum daily intake (TMDI) < acceptable daily intake (ADI) and < maximum permissible intake (MPI), percent acute hazard index (% aHI) <1, and percent chronic hazard index (% cHI) <1 for both novaluron and lambda-cyhalothrin suggested that the combination formulation is safe and will not pose any dietary risk to the consumers. The study will be helpful to conduct risk assessment of other pesticides/combination pesticides on food crops on which their MRLs have not yet been fixed.

Dissipation pattern and risk assessment of flubendiamide on chili at different agro-climatic conditions in India

Dissipation pattern and risk assessment of flubendiamide and its metabolite (desiodo flubendiamide) on chili were studied at four different agro-climatic locations of India at the standard and double dose at 60 and 120 g a.i. ha(-1) at 10 days interval. Quantification of residues was done on a high-performance liquid chromatograph (HPLC) with a photo diode array detector. The limit of quantification (LOQ) of this method was found to be 0.01 mg kg(-1) while limit of detection (LOD) being 0.003 mg kg(-1). Residues of flubendiamide were found to be below the determination limit in 15 days at both the dosages in all locations. Half-life of flubendiamide when applied at 60 and 120 g a.i. ha(-1) ranged from 0.85 to 1.80 and from 0.95 to 2.79 days, respectively. On the basis of data generated under the All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 1 day has been recommended and the flubendiamide 480 SC has been registered for use on chili in India by the Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on chili has been fixed by the Food Safety Standard Authority of India, Ministry of Health and Family Welfare, Government of India, as 0.02 μg g(-1) after its risk assessment.

Computed Tomography in the Evaluation of Pathological Lesions of Paranasal Sinuses

BACKGROUND

Computed tomography is now the modality of choice for imaging paranasal sinuses and along with Functional Endoscopic Sinus Surgery has empowered the modern rhinologist to treat patients more effectively. This study aims to evaluate anatomical variation in paranasal sinuses; compare computed tomography with histopathological and surgical findings and establish its diagnostic value.

METHODS

A hospital based observational study including all patients referred from the department of Ear, Nose and Throat for computed tomography scan of paranasal sinus to the department of radiology and imaging of Trubhuvan University Teaching Hospital from August 2011 to July 2012. Both axial and coronal sections were evaluated and findings were correlated with surgical findings and histopathology.

RESULTS

A total of 44 patients were included in the study. The most common clinical diagnosis was sinonasal polyposis and chronic rhinosinusitis. Most common anatomical variation was deviated nasal septum (68.2%) followed by choncha bullosa(27%). In most cases more than one sinus was involved. Maxillary sinus was involved in 90.9% followed by ethmoid sinus in 81.8%. Inflammatory pathology was seen in 35 (79.5%) patients with sinonasal polyposis pattern being the most common pattern of involvement. Findings of computed tomography were similar to surgical findings in 84.6% cases. The sensitivity and specificity of computed tomography was fairly good except for fungal rhinosinusitis.

CONCLUSIONS

CT scan should be performed preoperatively in order to guide the surgeon for Functional Endoscopic Sinus Surgery or other surgical procedures.

Residual behavior and risk assessment of flubendiamide on tomato at different agro-climatic conditions in India

Supervised field trials were conducted at four different agro-climatic zones in India to evaluate the dissipation pattern and risk assessment of flubendiamide on tomato. Flubendiamide 480 SC was sprayed on tomato at 48 and 96 g active ingredient (a.i.) ha(-1). Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10, 15, and 20 days after treatment. Quantification of residues was done on a high-performance liquid chromatography (HPLC) device with a photo diode array detector. The limit of quantification (LOQ) of this method was found to be 0.01 mg kg(-1) while limit of detection (LOD) being 0.003 mg kg(-1). Residues of flubendiamide were found below the determination limit of 0.01 mg kg(-1) in 20 days at both the dosages in all the locations. The half-life of flubendiamide at an application rate of 48 g a.i. ha(-1) varied from 0.33 to 3.28 days and at 48-g a.i. ranged from 1.21 to 3.00 days. On the basis of data generated under the All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 1 day has been recommended, and the flubendiamide 480 SC has been registered for its use on tomato by the Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on tomato has been fixed by the Ministry of Health and Family Welfare, Government of India under Food Safety Standard Authority of India, as 0.07 μg g(-1) after its risk assessment.

Safety evaluation of flubendiamide and its metabolites on cabbage and persistence in soil in different agroclimatic zones of India

Supervised field trials following good agricultural practices were conducted at the research farms of four agricultural universities located at four different agroclimatic zones of India to evaluate the persistence and dissipation of flubendiamide and its metabolite, des-iodo flubendiamide, on cabbage. Two spray applications of flubendiamide 480 SC of standard and double dose at the rate of 24 and 48 g a.i. ha(-1) were given to the crop at a 15-day interval, and the residues of flubendiamide 2 h after spray were found in the range of 0.107-0.33 and 0.20-0.49 mg kg(-1) at respective doses. Residue of des-iodo flubendiamide was not detected in any cabbage sample during study period. No residues were found in the soil samples collected from all treated fields after 15 days of application. On the basis of data generated under All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 10 days has been recommended, and the flubendiamide 480 SC has been registered for its use on cabbage by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on cabbage has been fixed by the Ministry of Health and Family Welfare, Government of India, under Food Safety Standard Authority of India as 0.05 μg/g after its risk assessment.

Dissipation and persistence of flubendiamide and thiacloprid in/on tomato and soil

Flubendiamide, a phthalic acid diamide protects the plants against a broad range of economically important lepidopterus pests and thiacloprid a second generation neonicotinoid is effective against the sucking insects, white flies and jassids. To estimate the residues of flubendiamide and thiacloprid on tomato, analytical methods were validated by conducting recovery studies, residues were quantified by using HPLC on C(18) column and PDA at 260 λ. Residues of flubendiamide declined below detectable level of 0.01 mg kg(-1) after 5 and 7 days of application at lower and higher dose with RL(50) of 0.72 and 1.32 days, respectively. Thiacloprid residues reached below its detectable level of 0.01 mg kg(-1) after 5 and 7 days of its lower and higher dose with RL(50) of 0.83 and 1.79 days, respectively.

Dissipation study of Quinalphos (25 EC) in/on brinjal and soil

A field experiment was conducted at Agricultural Research Station, Durgapura, Jaipur during kharif 2008 to study the dissipation of Quinalphos (25 EC) in/on brinjal and soil, when sprayed at its recommended dose (375 g a.i. ha(-1)) and double of the recommended dose (750 g a.i. ha(-1)). The residue data revealed the magnitude of dissipation and persistence by calculating safety parameters like RL(50) and T(tol). The initial deposit of Quinalphos in brinjal at 375 and 750 g a.i. ha(-1) were recorded as 0.0866 and 0.1517 mg kg(-1), respectively which reached to below detectable level (0.01 mg kg(-1)) in 7 and 10 days at recommended (375 g a.i. ha(-1)) and double of the recommended dose (750 g a.i. ha(-1)), respectively. The residues, however, had a half life value (RL(50)) of 2 days for lower dose and 3 days for higher dose. Hence 6 and 9 days waiting period was suggested for recommended and double of the recommended dose, respectively. No residues were detected in soil in treated plots at both the treatment levels 30 days after the spray of insecticide to the crop.

Persistence of propineb (polymeric zinc 1,2-propylene bisdithiocarbamate) fungicide in onion and cropped soil

To study the persistence of propineb in/on onion a field experiment was conducted during 2007 at Agricultural Research Station, Durgapura, Jaipur Propineb70WP @ 1,225 and 2,450 g a. i. ha(-1) dose was applied as foliar spray to the crop thrice at an interval of 10 days. After third spray, onion samples comprising of green leaves and immature bulb were collected at 0,1,3,5,7,10 and 15 days. The initial deposit was 2.32 and 4.89 ppm of propineb (on CS(2) basis) which persisted up to the 10 and 15 days at normal 1,225 g a.i. ha(-1) and higher 2,450 g a.i. ha(-1) dose of fungicide application. The half life values of propineb ranged from 3.27 to 4.60 days.

Disappearing cardiac masses--the importance of intraoperative transesophageal echocardiography

A 25-year-old man presented with sudden onset right-sided hemiplegia. Transthoracic and transesophageal echocardiograms demonstrated a mobile mass attached to the anterior mitral leaflet. The mass was, however, not found at operation.