Dissipation kinetics and the evaluation of dietary risks associated with deltamethrin, ethion, fenazaquin, and fenpropathrin on bell pepper (Solanum annuum L.).

Bell peppers, a globally significant crop, face infestations from various pests. In a study, bell peppers were treated with deltamethrin, ethion, fenazaquin, and fenpropathrin at recommended and double the doses, repeated twice with a 10-day interval. The QuEChERS method underwent validation for linearity, matrix match, accuracy, and precision in bell pepper matrices for residue analysis. The limit of detection for the tested pesticides on bell peppers was 0.01 mg/L, with a quantification limit of 0.05 mg/L. Recovery studies showed a range of 94.80% to 102.80%. Initial deposits of deltamethrin, ethion, fenazaquin, and fenpropathrin on bell peppers at recommended doses were 0.371, 1.237, 0.617, and 0.640 mg/L, respectively, and at double doses were 0.712, 1.945, 1.221, and 1.189 mg/L, respectively. Safe waiting periods of 10, 11, 10, and 8 days were suggested for deltamethrin, ethion, fenazaquin, and fenpropathrin, respectively. The corresponding half-lives for the pesticides were 1.96, 1.79, 2.06, and 1.69 days, all following first-order dissipation kinetics. Dietary risk assessment indicated Hazard Quotients (HQ) below 1 and Theoretical Maximum Daily Intake (TMDI) below Acceptable Daily Intake (ADI) and Maximum Permissible Intake (MPI) levels. Therefore, at their recommended doses, the pesticides were deemed safe for bell pepper cultivation.

Residue estimation and dietary risk assessment of fenvalerate, novaluron, and profenofos in bell pepper grown under protected and open field conditions.

Residue studies were conducted in bell pepper crops (green and yellow bell pepper) to ensure the safe use of fenvalerate, profenofos, and novaluron (under open field and protected conditions) in randomized block design (RBD) following three applications at a 10-day interval over two consecutive years, 2021 and 2022. A robust analytical method was developed using quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) for the determination of pesticide residues in bell pepper samples. The half-lives for fenvalerate were 2.47-2.87 and 2.50-3.03 days on bell pepper under open field conditions, whereas the corresponding values for bell pepper under protected conditions were 3.84-4.58 and 4.17-4.71 days, during 2021 and 2022, respectively. Profenofos displayed half-lives of 2.03-2.65 and 2.15-2.77 days in open field conditions and 3.05-3.89 and 3.16-3.78 days in protected conditions during 2021 and 2022, respectively. Similarly, novaluron had half-lives of 2.87-3.49 and 3.24-3.75 days under protected conditions in 2021 and 2022, respectively. The maximum residue limits (MRLs) were calculated to be 0.6 mg/kg for fenvalerate, while for profenofos it was 0.7 mg/kg on bell pepper under open field conditions at double doses, at the proposed pre-harvest interval (PHI) of 3 days. Likewise, for bell peppers grown under protected conditions, MRLs at the PHI of 3 days were determined to be 0.8 mg/kg for fenvalerate, 0.3 mg/kg for novaluron, and 1.5 mg/kg for profenofos. A dietary risk assessment study indicated that the percentage of acute hazard index (% aHI) was significantly lower than 100, and hazard quotient (HQ) values were below 1, signifying no acute or chronic risk to consumers. These findings underscore the safety of consuming bell peppers treated with fenvalerate, profenofos, and novaluron under the protected and open field conditions.

Dissipation pattern and dietary risk assessment of some commonly used insecticides on tomato (Solanum lycopersicum L.).

Pesticide residue in food commodities is a serious concern in relation to consumer safety and also the most significant barrier in the trade of food commodities. The dissipation pattern of four insecticides, namely novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin, was evaluated on tomato fruits and cropped soil. The residues were extracted using the QuEChERS analytical method and quantized using a gas chromatograph with electron capture detector, gas chromatograph mass spectrometer, and high-performance liquid chromatography with photo diode array detector. The analytical method was validated using parameters like recovery, linearity, accuracy, matrix effect, and specificity, with limit of detection and limit of quantitation established to be 0.01 and 0.05 mg/kg, respectively, for all the pesticides. The average initial deposits (samples collected after 2 h of application) at the recommended dose of novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin were 0.593, 0.293, 0.227, and 0.431 mg/kg on tomato fruits, respectively, and were below the limit of quantification in soil. The pre-harvest interval of 17, 8, 1, and 13 days was suggested for novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin on tomato, respectively. Risk assessment studies revealed that all pesticides under study are safe and do not pose any threat to humans as theoretical maximum dietary intake is less than the maximum permissible intake and acceptable daily intake.

A comparison between revised Manchester Point A and ICRU-89-recommended Point A definition absorbed-dose reporting using CT images in intracavitary brachytherapy for patients with cervical carcinoma.

PURPOSE: This study is a comparison between revised Manchester Point A and International Commission on Radiation Units and measurements (ICRU) 89 report-recommended Point A absorbed-dose reporting in intracavitary brachytherapy for patients with cervical carcinoma. METHODS AND MATERIALS: The retrospective dosimetric study is based on the data of 32 patients with cervical carcinoma treated with high-dose-rate brachytherapy. Patients received 21 Gy in three fractions (7.0 Gy X three fractions) to Point A (Aflange, revised Manchester definition). All the patients were replanned with a new Point A (Aicru89) defined on CT images as per the American Brachytherapy Society/ICRU-89. The data collected were compared with the data obtained from Point A (Aflange). RESULTS: When using the Aflange plan normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 820.79 ± 207.47 cGy, 654.66 ± 152.69 cGy, and 588.91 ± 136.35 cGy, respectively. Likewise, when using the ICRU-89 Point Aicru89 normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 869.30 ± 224.67 cGy, 693.24 ± 166.20 cGy, and 616.61 ± 150.32 cGy, respectively. For the rectum, Point Aflange normalization plans, the mean dose of 0.1 cc, 1 cc, and 2 cc volumes was 589.37 ± 163.26 cGy, 487.51 ± 126.03 cGy, and 442.70 ± 111.43 cGy, respectively. Likewise, using the Aicru89 plan, the mean 0.1 cc, 1 cc, and 2 cc rectum volume was 625.07 ± 171.31 cGy, 517.50 ± 131.05 cGy, 464.94 ± 121.81 cGy, respectively. The statistical mean difference of Total Reference Air Kerma rate, V100 (cc), bladder, rectum and sigmoid, was found significant. CONCLUSIONS: It has been found that the position of revised Manchester (Aflange) and ICRU-89 Point A does not match on CT images/radiograph, which resulted in variation in doses to the tumor, V100 (cc), organ at risk, and Total Reference Air Kerma.