Tracking neonicotinoids following their use as cotton seed treatments

Neonicotinoids are a leading class of insecticides on the global market, accounting for nearly 25%. They are widely used in both agricultural and residential settings. Causing neuron failure by irreversibly binding to the insect nicotinic acetylcholine receptor, neonicotinoids offer broad spectrum efficacy against a variety of pests. However, because they are non-selective with regard to insect species, there has been some concern with neonicotinoid use over threats to pollinators such as honeybees, and potential indirect effects to migratory waterfowl as a result of invertebrate prey population depletion. In order to study occurrence and fate of neonicotinoids (thiamethoxam and imidacloprid), we analyzed cotton leaves on plants grown from neonicotinoid-treated seeds and corresponding soil samples between cotton rows. Neonicotinoid concentration data from cotton leaves appears to be consistent with the claim that seed treatments protect plants for 3–4 weeks; by 30 days post-planting, neonicotinoid concentrations fell, in general, to 200 ng/g or lower. This represents about a 10-fold decrease from plant concentrations at approximately 2 weeks post-planting. It was found that neonicotinoids used as seed treatments remained present in the soil for months post planting and could be available for runoff. To that end, 21 playa wetlands were sampled; 10 had at least one quantifiable neonicotinoid present, three of which were classified as grassland or rangeland playas, two were urban, and the remaining five were cropland playas. In several instances, neonicotinoid concentrations in playas exceeded EPA chronic benchmarks for aquatic invertebrates

Repeated infections of dengue (serotype DENV-2) in lung cells of BALB/c mice lead to severe histopathological consequences

To determine the effect of DENV (serotype 2) repeated infections on lung cells is the main goal of this study. From the result, lung histology of control BALB/c mice showed normal alveolar morphology, while vehicle control BALB/c mice highlighted a slight thickening of the alveolar septum. Lung histopathology of BALB/c mice infected twice by DENV-2 showed the presence of hemorrhage, plasma leakage and presence of hemosiderin-laden macrophages (HLMs). Notably, in the lung of BALB/c mice infected four times by DENV-2, we observed thickening and disruption of the alveolar septum, inflammatory cell infiltration, plasma leakage and increased cellularity. Megakaryocyte releasing platelets were also found into the lung alveolus. Overall, our findings showed severe histopathological damage in lungs repeatedly infected by DENV-2, allowing us to argue that they can be linked to pulmonary complication. Result also showed that the number of infections with similar total DENV-2 titer led to different histopathological changes

Dissipation Behavior of Fenpyroximate Residues in Black Tea and Brew

Fenpyroximate is an effective acaricide on several food crops. In the present study, dissipation of residue of this acaricide in black tea, tea infusion and spent tea was studied. Analysis was carried out using high performance liquid chromatography with diode array detection. The rate of dissipation was found to vary with the nature of the substrate. In tea leaves the half-life of fenpyroximate ranged from 2.20 to 4.22 days. The residue of fenpyroximate was not detectable in the tea brew.</p

Residues of Propargite in Tea

Propargite is an acaricide extensively used in India for controlling the populations of the red spider mite (RSM) infesting tea. Field experiments were conducted at two places in Tamil Nadu (India) during the dry season to determine the residues of propargite in black tea. Residues were quantified at different harvest intervals of ‘0’ (3 hr), 1st, 3rd, 5th, 7th, 10th and 14th day after acaricide application. Persistence,&nbsp; issipation pattern, half-life value and safe harvest interval of the acaricide in tea were calculated. Residues of propargite dissipated exponentially after application at both the locations and reached below the CODEX MRL of 5 mg/kg on the 7th day. Regression lines drawn on propargite showed that like other acaricides it followed the first order dissipation kinetics. Half-life values varied from 1.63 to 1.92 days for propargite and a safety harvest interval of 7 days is suggested for the tea crop.</p

Influence of Life-History Parameters on Persistent Organic Pollutant Concentrations in Blubber of Eastern North Pacific Gray Whales (Eschrichtius robustus).

Exposure to persistent organic pollutants (POPs) can significantly impact marine mammal health, reproduction, and fitness. This study addresses a significant 20-year gap in gray whale contaminant monitoring through analysis of POPs in 120 blubber biopsies. The scope of this substantial sample set is noteworthy in its range and diversity with collection between 2003 and 2017 along North Americas west coast and across diverse sex, age, and reproductive parameters, including paired mothers and calves. Mean blubber concentrations of polychlorinated biphenyls (∑PCBs), dichlorodiphenyltrichloroethanes (∑DDTs), and chlordanes (∑CHLs) generally decreased since previous reports (1968-1999). This is the first report of polybrominated diphenyl ethers (PBDEs) and select hexachlorocyclohexanes (HCHs) in this species. Statistical modeling of the 19 most frequently detected compounds in this dataset revealed sex-, age-, and reproductive status-related patterns, predominantly attributed to maternal offloading. Mean POP concentrations differed significantly by sex in adults (17 compounds, up to 3-fold higher in males) but not in immatures (all 19 compounds). Mean POP concentrations were significantly greater in adults versus immatures in both males (17 compounds, up to 12-fold) and females (13 compounds, up to 3-fold). POP concentrations were detected with compound-specific patterns in nursing calves, confirming maternal offloading for the first time in this species