Microplastics are pervasive and persistent emerging contaminants found across freshwater and marine ecosystems, posing significant ecological risks to aquatic organisms. This study investigated the spatio-temporal distribution and ecological risks of microplastics in water and sediment of the downstream Ganges River of Bangladesh. Water and sediment samples were collected from nine sampling sites during pre-monsoon and post-monsoon seasons of 2024 and 2025. A total of 108 samples were analyzed using digestion, density separation, stereomicroscopic observation, and polymer identification. Microplastics were widely distributed in water (7.7 to 18.2 MPs/L) and sediment (1601 to 3813 MPs/kg) across the study area. FTIR analysis identified polyethylene (PE) (27
This technical note reports selected trace metals in four major surface-water reservoirs associated with the Houston metropolitan region. Shoreline surface-water samples from Lake Houston, Lake Livingston, Lake Conroe, and Clear Lake were analyzed for As, Cd, Cu, Pb, Ni, and Zn by inductively coupled plasma-mass spectrometry (ICP-MS) following U.S. EPA Method 200.8 quality-control procedures. Copper was the dominant analyte in all reservoirs, with mean concentrations of 9.82–15.5 µg L⁻¹. Measured concentrations were low, and arsenic and lead were below relevant federal drinking-water benchmarks. These results provide a concise descriptive baseline for future reservoir monitoring.
Over the past few years, copper (Cu) has been considered the contaminant posing the greatest risk in aquatic environments. This study, therefore, aimed to evaluate species sensitivity and Cu hazards to aquatic organisms in freshwater and saltwater ecosystems. The results showed that there was no significant difference in Cu hazards between the two environmental matrices, with 5
Present report aimed to investigate the cytogenotoxic potential of sublethal concentrations (0.05 ppm) of diesel and petrol automobile exhaust nanoparticles (DAENPs and PAENPs) in erythrocytes of the freshwater fish Channa punctatus. Morphological alterations, nuclear abnormalities, micronuclei (MNs), oxidative stress, DNA damage, and apoptosis were assessed. Increased frequencies of morphological alterations ( average of 7.12 ± 0.71, and 7.24 ± 0.84 in DAENPs- and PAENPs- treated fish, respectively), nuclear alterations( average of 10.60 ± 1.97, and 11.99 ± 1.24 in DAENPs- and PAENPs- treated fish, respectively) and MNs (13.83 ± 0.16, and 11.83 ± 1.58 in DAENPs- and PAENPs- treated fish, respectively) were found. Similarly, compared with that in the control group, the level of malondialdehyde, a byproduct of lipid peroxidation was significantly greater, while the level of reduced glutathione was lower in the DAENPs- and PAENPs-exposed fish. The comet analysis parameters revealed that both DAENPs and PAENPs induced DNA damage. Annexin-V FITC/PI assay data demonstrate that DAENPs and PAENPs led to the induction of apoptosis. The present report suggests that morphological and nuclear alterations in the erythrocytes of experimental fish occur in response to genotoxic and oxidative stress induced by DAENPs and PAENPs. Furthermore, the observed apoptosis indicates DNA damage induced by the exhaust nanoparticles in fish erythrocytes.
The rivers of the Tisza basin have complex geology, tectonics, and morphology and traverse different landscape zones, from mountainous areas to lowlands. This affects the composition and properties of the water of the Tisza River, which, in turn, influence the state of the Danube River. Bioaccumulation of heavy metals (HM) and radionuclides (RN) by indigenous ichthyofauna can serve as an indicator of the ecological status of rivers. This study presents the identified patterns in the bioaccumulation of selected HM (Cd, Pb, Zn, and Cu) and natural gamma-active RN (the 238U and 232Th series) by a representative of the indigenous ichthyofauna, Squalius cephalus L., in the upper reaches of rivers of the Tisza basin. There is a general trend towards increasing HM content in Squalius cephalus L. samples along the riverbed across sections extending from mountainous to foothill landscape zones. This trend is associated with changes in the geology, tectonics and morphology of the river basin. An increase in the Zn/Cu ratio (from 10.6 to 19.2) in fish samples along the riverbed from mountainous to foothill landscapes was observed. The total specific activity of RN in Squalius cephalus L. samples ranges from 34.2 to 88.8 Bq⋅kg-1 and tends to decrease from mountainous to lowland landscapes. The ∑232Th/∑238U ratio ranges from 0.86 to 1.42. In mountainous landscapes, RNs in the 238U series make a significant contribution to the total specific radioactivity.
