One cationic surfactant with a wide spectrum of microbiocidal activity is benzethonium chloride (BEC). Despite being widely used, the toxicity data on vertebrate organisms are limited. Therefore, we aimed to evaluate within this study the acute toxicity of BEC on the gills and kidneys of Cyprinus carpio (European carp). An alteration of the antioxidant enzymes activities (glutathione reductase, glutathione peroxidase and glutathione S-transferase) was noticed after 96 h of exposure, along with an elevation of lipid peroxidation and decreased concentration of reduced glutathione, which confirmed that BEC was able to induce toxicity to these tissues. These metabolic effects were correlated with unspecific structural changes observed in gills and kidneys, having moderate degree of severity (such as an increase of melanomacrophages aggregation incidence and cytoplasm vacuolation of goblet cells in collecting tubules) and generally being compatible with life for the exposure time studied. The most severe structural effects were observed in gills after 96 h, noticing a lamellar aneurysm, hemorrhages and lamellar epithelium disruption due to the blood vessels and pillar cells damages and increased blood flow inside the lamellae. By our research we can confirm the utility of biochemical and histological analyses in the fish organs as tools for monitoring the water quality and ecotoxicological potential of chemicals.

Benzenthonium chloride (BEC, Hyamine 1622) is a quaternary ammonium surfactant with cationic properties widely used in cleaning, sanitation, and medical products that can become harmful to humans and also to the environment. This study aimed to evaluate its acute effects on Cyprinus carpio fish in terms of oxidative stress and morphological changes on hepatic tissue in order to show the sub-lethal toxicity of BEC. Fish were exposed to 1 mg/L BEC for 24, 48, and 96 h, and the liver samples were collected. The most significant changes were noticed after 96 h of exposure when the entire antioxidant enzyme system was affected. The activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase decreased by 44%, 31%, 30%, and 45%, respectively, compared to control. Glucose-6-phosphate dehydrogenase activity decreased by 29% after 96 h of control, inducing a reduction of NADPH formation which decreased by half the level of reduced glutathione, the main non-enzymatic antioxidant. These effects correlated with the raised value of lipid peroxidation after 96 h and the morphology changes on hepatic tissue, such as cytoplasmic vacuolization and nuclear hypertrophy that could affect the normal function of the liver. All of these results showed acute toxicity of BEC on C. carpio after 96 h of exposure, causing oxidative stress response at the hepatic level.

Contamination of agricultural ecosystems with antibiotics including sulfamethoxazole (SMX) can create favorable conditions to increase bacterial abundance in soil with antibiotic-resistant genes and can also affect plants. The aim of this research was to assess the phytotoxicity of tomato after irrigation with SMX degraded in 20 min using the non-thermal plasma-ozonation technique (T20). To achieve this, two experiments were performed at the scales of Petri dishes and pots using Solanum lycopersicum L. species, cultivar Zaraza, subjected to irrigation treatments that were compared to a distilled water control. In plates, T20 solution improved root length and also seedling vigor indexes, but the germination index, germination speed, and biomass were slightly decreased. In soil, although T20 reduced the seedling root length, their growth was not inhibited (15.3%), while in plates they exhibited a growth promotion effect with 90% more than the control. The physical–chemical and geochemical variables measured in the soil were suitable for crop characteristics and plant growth and showed statistically significant variations after harvesting. In T20-treated shoots, compared to SMX, better results were obtained for their length, assimilatory pigments, and biomass, thus selectively reducing the tomato seedling phytotoxicity depending on the endpoints, type of control, and growth methods tested.

Calcium oxalate (CaOx) crystals in plants can form naturally within their idioblasts but may also be induced by other factors, such as environmental pollution. Here, we report qualitative and semiquantitative results obtained using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) from two experiments in which tomato seedlings were moderately irrigated with Sulfamethoxazole (SMX) and Amoxicillin (AMX) solutions (0.25 mM). Abundant prismatic CaOx co-crystals appeared on the leaf surface induced by these two antibiotics compared to the distilled water (DW) control. Applying a non-thermal plasma (NTP) treatment for 20 min (T20) to the SMX initial solution led to a dramatic suppression of these crystals, with a shift toward spherical structures. Furthermore, the investigation into the composition of both crystal types, indicated different percentual levels of O, C, Ca, K, Mg, S, and Mn as main constituent minerals involved in crystal formation. However, crystal morphology was affected by each applied experimental condition, while detecting their constituent elements depended on their mineral homogeneity at the micro- or macro-field scales. Although both antibiotics induced crystal formation and T20 phenotypically reduced the abundance of the acicular–prismatic crystals by removing the effects of SMX, their mode of action has not yet been clarified.