The microanatomy of several oribatid and one acaridid mite was studied to determine the role of free cells (haemocytes) in mites. Mites from the field as well as laboratory cultures were observed and analyzed histologically using Masson triple stain. The mites were offered various foods and kept in fluctuating moisture conditions. The presence of haemocytes was significantly correlated with the transport between internal organs of various substance. Three types of transport were recorded: (i) enzymes into the alimentary tract, including the incorporation of haemocytes into the gut walls. This process seemed to be correlated with the amount and type of food and frequently with the presence of internal extraintestinal bacteria associated with mesenchyma; (ii) metabolites, like guanine from mesenchyma into the alimentary tract followed by expulsion from the body via the gut. This process is correlated with food of high nitrogen content or dry conditions; (iii) resorption of nutrients from eggs during an induced quiescent state under unfavourable conditions by small haemocytes.
Treated water from wastewater treatment plants that is increasingly used for irrigation may contain pharmaceuticals and, thus, contaminate soils. Therefore, this study focused on the impact of soil conditions on the root uptake of selected pharmaceuticals and their transformation in a chosen soil–plant system. Green pea plants were planted in 3 soils. Plants were initially irrigated with tap water. Next, they were irrigated for 20 days with a solution of either atenolol (ATE), sulfamethoxazole (SUL), carbamazepine (CAR), or all of these three compounds. The concentrations of pharmaceuticals and their metabolites [atenolol acid (AAC), N1-acetyl sulfamethoxazole (N1AS), N4-acetyl sulfamethoxazole (N4AS), carbamazepine 10,11-epoxide (EPC), 10,11-dihydrocarbamazepine (DHC), trans-10,11- dihydro-10,11-dihydroxy carbamazepine (RTC), and oxcarbazepine (OXC)] in soils and plant tissues were evaluated after harvest. The study confirmed high (CAR), moderate (ATE, AAC, SUL), and minor (N4AC) root uptake of the studied compounds by the green pea plants, nonrestricted transfer of the CAR species into the different plant tissues, and a very high efficiency in metabolizing CAR in the stems and leaves. The results showed neither a synergic nor competitive influence of the application of all compounds in the solution on their uptake by plants. The statistical analysis proved the negative relationships between the CAR sorption coefficients and the concentrations of CAR, EPC, and OXC in the roots (R = –0.916, –0.932, and –0.925, respectively) and stems (R = –0.837, –0.844, and –0.847, respectively).