The consequence of the unstoppable growth of plastic production and inadequate waste disposal is plastic pollution, which is becoming a global challenge. Large quantities of discarded plastics in the environment are under the direct influence of biotic and abiotic factors, leading to the fragmentation of particles and the formation of tiny particles of plastics or nanoplastics. Nanoplastics are a fast‐growing pollutant that, due to ubiquity in the environment, causes great public concern. It also attracts the attention of scientists in detecting harmful effects on health and the environment. This review is aimed at summarizing all adverse effects of nanoplastics on human health and the environment. Due to their toxic effects, it is necessary to reduce the disposal of plastics in the environment, develop or improve existing methods, and implement legislation that would reduce the release of nanoplastics into the environment. A possible ban or reasonable regulation of nanoplastics in cosmetics or food can be expected only after a critical mass of scientific objections has been created.

In recent years, compounds from the Schiff base group have been intensively studied for their biological activities. Accordingly, a series of Schiff bases were synthesized from substituted aromatic aldehydes (5-chlorosalicylaldehyde) and differently substituted aromatic amines and their antimicrobial activities were evaluated. The molecular identity of compounds was confirmed using various spectroscopic techniques, such as IR and NMR spectroscopy and elemental analysis, and the molecular structure of compound 3k was determined by single-crystal X-ray analysis. The antimicrobial activity of 3a–3k compounds was examined in sixteen microorganisms (five species of bacteria and eleven species of fungi) using the microdilution method. Regarding antibacterial activity, a remarkable MIC value (0.0098 mg mL⁻¹) and, therefore, the best activity was displayed against Proteus mirabilis for 3e, which is even stronger than the most frequently used antibiotic medications. 3f showed the best antifungal activity against Microsporum gypseum, which is stronger than standard antimycotic fluconazole, and is also an important result considering that Microsporum gypseum can cause dermatophytosis in both humans and animals.

In this paper, the synthesis, characterization, and biological evaluation of the novel tetrahydropyrimidines—THPMs are described. THPMs are well-known for wide pharmacological activities such as antimicrobial, anticancer, antiviral, etc. This research includes obtained results of in vitro antimicrobial, anticancer, and α-glucosidase inhibitory activities of the eleven novel THPMs. An antibiotic assessment was done against five bacteria (two Gram-positive and three Gram-negative) and five fungi by determining the minimal inhibitory concentration (MIC), using the broth tube dilution method. The most active antibacterial compounds were 4a, 4b, and 4d, while the best antifungal activity was shown by 4e, 4f, and 4k. The lowest MIC value (0.20 mg/mL) was measured for 4e, 4f, and 4k against the Trichophyton mentagrophytes. Moreover, examining the α-glucosidase inhibitory activity revealed the compound 4g as the one with the best activity. The cytotoxic activity was performed on the tumor cell lines (HeLa, K562, and MDA-MB-231) and normal cells (MRC-5). The best antitumor activity was shown by compounds 4b and 4k against HeLa cell lines. The influence on cell cycle and mechanism of action of the most active compounds were examined too. Compound 4b had good antibacterial and anticancer activities, while 4k showed promising antifungal and anticancer activities.