Acute and Chronic Effects of Clothianidin, Thiamethoxam and Methomyl on Chironomus dilutus

Organism tolerance thresholds for emerging contaminants are vital to the development of water quality criteria. Acute (96-h) and chronic (10-day) effects thresholds for neonicotinoid pesticides clothianidin and thiamethoxam, and the carbamate pesticide methomyl were developed for the midge Chironomus dilutus to support criteria development using the UC Davis Method. Median lethal concentrations (LC50s) were calculated for acute and chronic exposures, and the 25% inhibition concentrations (IC25) were calculated for the chronic exposures based on confirmed chemical concentrations. Clothianidin effect concentrations were 4.89 µg/L, 2.11 µg/L and 1.15 µg/L for 96-h LC50, 10-day LC50 and 10-day IC25, respectively. Similarly, thiamethoxam concentrations were 56.4 µg/L, 32.3 µg/L and 19.6 µg/L, and methomyl concentrations were 244 µg/L, 266 µg/L and 92.1 µg/L. Neonicotinoid effect concentrations compared favorably to previously published 96-h and 14-day LC50 concentrations, and methomyl effect concentrations were within the acute survival range reported for Chironomus species and other organisms.

Effects of Acute and Chronic Stretching on Pain Control

ABSTRACT While muscle stretching has been commonly used to alleviate pain, reports of its effectiveness are conflicting. The objective of this review is to investigate the acute and chronic effects of stretching on pain, including delayed onset muscle soreness. The few studies implementing acute stretching protocols have reported small to large magnitude decreases in quadriceps and anterior knee pain as well as reductions in headache pain. Chronic stretching programs have demonstrated more consistent reductions in pain from a wide variety of joints and muscles, which has been ascribed to an increased sensory (pain) tolerance. Other mechanisms underlying acute and chronic pain reduction have been proposed to be related to gate control theory, diffuse noxious inhibitory control, myofascial meridians, and reflex-induced increases in parasympathetic nervous activity. By contrast, the acute effects of stretching on delayed onset muscle soreness are conflicting. Reports of stretch-induced reductions in delayed onset muscle soreness may be attributed to increased pain tolerance or alterations in the muscle's parallel elastic component or extracellular matrix properties providing protection against tissue damage. Further research evaluating the effect of various stretching protocols on different pain modalities is needed to clarify conflicts within the literature.

Гігієнічні нормативи хімічних речовин в атмосферному повітрі: досягнення минулого та сучасні погляди у майбутнє

Objective: We generalized and assessed the prior chemical pollutants in accordance with the time of their averaging by the data of domestic and foreign regulatory frameworks. Materials and methods: To achieve the goal, we used the bibliographic and analytical methods. We analyzed the databases of Ukraine and the EU countries, the USA and Canada on the current standards for chemical agents and the time of their averaging in accordance with the purpose - prevention of acute and chronic effects. Results and discussion: As a result of the comparison of the data on the regulations and standards for chemical agents in ambient air, we identified the agents that are criterial ones in most countires. For these substances, monitoring methods have been developed and standards have been substantiated and adopted for two averaging periods: twenty-minute and average daily. In most countries, two standards have been also adopted for each agent, but the averaging period is longer there: an average annual and a daily average. Such standards may control and prevent the chronic effect of substances. As a result, the use of the Ukrainian and foreign standards leads to the controversial estimates of the actual air pollution. The average daily standard adopted in Ukraine, on the one hand, is much stricter in comparison with the similar foreign criteria, and on the other hand, it does not correspond to the peculiarities of the formation of ambient air pollution, and is inadequate for the averaging time. Conclusions: 1. Comparative analysis of hygienic standards indicates the needs to harmonize the ambient air quality standards in force in Ukraine with international ones. 2. The existing system of the hygienic standards in Ukraine must be supplemented with the standard for the annual averaging period by transferring the operating average daily concentrations to this rank.

The use of e-cigarettes and its risk of respiratory diseases

There are increasing concerns about the impact of using e-cigarettes on the overall health and respiratory complications of users. These modalities were proposed to potentially reduce the harmful events that are associated with cigarette smoking. Nevertheless, the acute and chronic effects secondary to the exposure and use of this modality are still controversial. However, it has been demonstrated that using the modality is associated with remarkable damage to lung injury because it releases significant amounts of reactive oxygen species, furans, volatile carbonyls, furans and metals (chromium, lead, and nickel). We have discussed the impact of e-cigarette using and exposure to its aerosol and the development and progression of the different respiratory diseases at the different clinical and pathological levels. Asthma, chronic bronchitis were the most significant lung conditions, and evidence indicated that exacerbation of symptoms was reported in some patients. Furthermore, acute exposure was also associated with the development of respiratory-related symptoms. Accordingly, studies indicated severe inflammatory reactions and significant lung injury were observed among e-cigarette users concerning vaping or exposure. Therefore, further preventive approaches are required by healthcare authorities to increase public awareness of the different hazards of using these modalities.

Pharmaceutical Products and Pesticides Toxicity Associated with Microplastics (Polyvinyl Chloride) in Artemia salina

Pharmaceutical products, as well as insecticides and antimicrobials, have been extensively studied, but knowledge of their effects—especially those caused by their mixtures with microplastics—on aquatic organisms remains limited. However, it should be borne in mind that the state of knowledge on acute and chronic effects in aquatic organisms for pharmaceuticals and pesticides is not similar. In response, this investigation analyzed the presence of microplastics (polyvinyl chloride) and their impacts on the toxicity of chlorpyrifos (an insecticide) and triclosan (an antibacterial) when they coincide in the environment, alongside the two most consumed drugs of their type (hypolipemic and anticonvulsant, respectively), namely simvastatin and carbamazepine, in Artemia salina. LC50 and cholinesterase enzyme activity were calculated to determine the possible neurotoxicity associated with emergent contaminants in the treatments. The LC50 values obtained were 0.006 mg/dm3 for chlorpyrifos, 0.012 mg/dm3 for chlorpyrifos associated with microplastics, 4.979 mg/dm3 for triclosan, 4.957 mg/dm3 for triclosan associated with microplastics, 9.35 mg/dm3 for simvastatin, 10.29 mg/dm3 for simvastatin associated with microplastics, 43.25 mg/dm3 for carbamazepine and 46.50 mg/dm3 for carbamazepine associated with microplastics in acute exposure. These results indicate that the presence of microplastics in the medium reduces toxicity, considering the LC50 values. However, exposure to chlorpyrifos and carbamazepine, both alone and associated with microplastics, showed a decline in cholinesterase activity, confirming their neurotoxic effect. Nevertheless, no significant differences were observed with the biomarker cholinesterase between the toxicant and the toxicant with microplastics.