Bulletin of Environmental Contamination and Toxicology最新文献

This study evaluates a novel mixed bacterial culture, comprising Acinetobacter baumannii IITG19, Klebsiella michiganensis RK, Providencia vermicola IITG20, and Pseudomonas aeruginosa IITG21, for its effectiveness in remediating diesel-contaminated soil and water. Through in-Lab degradation efficiency tests, simulated field studies, phytotoxicity tests, and degradation kinetics analysis, the potential of this culture was explored. During in-Lab study, the mixed culture showed 90% degradation of 4% v/v diesel over 15 days, at 35 °C temperature, pH 7, and 1% v/v inoculum concentration. Subsequent field studies showed diesel degradation of 96 and 99% in soil and water, respectively. The mixed culture showed 97% degradation of n-alkanes and branched alkanes and 96% degradation of naphthenes and aromatics in soil. In water, it showed over 99% degradation for all components. Phytotoxicity assessments with Brassica nigra seeds, ascertained successful growth in mixed culture-treated soil and water due to remediation. Degradation kinetics analysis confirmed first-order degradation, with a rate constant (k) of 0.144 day^-1 for in-Lab study. Field studies yielded values of 0.196 day^-1 for soil and 0.288 day^-1 for water. These findings showed that the mixed bacterial culture in this study was not only able to remove diesel contamination from soil and water but also restored soil health for plant growth. Its efficient performance under field-like conditions established its real potential for use in large-scale environmental clean-up efforts.

We investigated the effects of settleable atmospheric particulate matter (SePM, 1 g L^-1, 96 h) on metal bioaccumulation and blood biomarkers of the estuarine fish Centropomus parallelus. After exposure, V, Cr, Ni, Cu, Mo, Ag, W, and Pb accumulated in erythrocytes, while V, Cr, Fe, Nb, Mo, and Pb were found in plasma. SePM increased erythrocyte nuclear abnormalities (89.9%) and micronuclei frequency (117.6%), while decreasing neutrophils (51.6%). The erythrocyte antioxidant system responded with higher CAT and SOD activity (18.4% and 54%) to mitigate biomolecular damage, yet lipoperoxidation (162%) and protein carbonylation (97.1%) persisted in erythrocytes, along with lipoperoxidation (91.3%) in plasma. Our findings demonstrate that SePM exposure alters antioxidant defenses and hematological responses. Observed mutagenic alterations indicate damage with potential ecological implications. Blood biomarkers thus represent sensitive, non-invasive tools for biomonitoring and early detection of stress in aquatic organisms exposed to SePM.

Sarus crane, Antigone antigone, is the tallest flying resident crane in India. As these birds use agricultural fields as foraging and nesting grounds, they are exposed to environmental contaminants from agricultural runoff. This study documents the presence of the residue of selected agrochemicals in the tissues of birds from electrocution. Vital tissues, including liver, muscle, kidney, brain, and gut content from 14 individuals, were analyzed to determine the presence of 67 pesticide residues using Gas Chromatography-Mass Spectrometry and Liquid Chromatography-Mass Spectrometry. Sixty-four percent of the birds that were tested had at least one pesticide residue. Out of 67 chemicals tested, residues of only 4 chemicals, namely Chlorpyrifos, Dichlorodiphenyltrichloroethane, Hexachlorocyclohexane, and Endosulfan, were at detectable levels. This study presents the first report on pesticide levels in A. antigone in Uttar Pradesh, India. Although the levels of pesticide detected were below the previously reported levels, the mortality due to pesticide poisoning and power lines across the entire distribution range of Sarus cranes in India remains a cause for concern.

Mussels have been widely used in ecotoxicological studies due to their filter-feeding activity and sessile lifestyle, which makes them a suitable bioindicator organism. Thus, freshwater mussels (Unio delicatus) were exposed to different concentrations (0, 0.5, 2.5, 12.5 mg/L) of ZnO nanoparticles (18 nm) for 14 days to investigate responses of biomarkers belonging to the antioxidant, osmoregulation and energy systems. Laboratory-cultured algae (Chlorella vulgaris) were served to mussels (approximately 250,000 algae/ml) during the experiments. Significant (p < 0.05) accumulation of Zn occurred only in the gills. Enzymes belonging to the gill osmoregulation system did not respond to ZnO NP exposures (p > 0.05). However, activities of antioxidant system enzymes were altered significantly (p < 0.05) in the digestive glands. Levels of glucose and lipid significantly (p < 0.05) decreased, resulting in a decrease in immediate energy reserves of mussels. Although ZnO nanoparticles exhibited low tissue accumulation, they affected the metabolic systems of U. delicatus, emphasising the potential effects of nanoparticles.

Microplastics can serve as sites for microbial attachment, however their role in facilitating biotoxin entry into marine food webs remains poorly understood. This study quantified the adsorption and desorption kinetics of brevetoxin 3 (PbTx-3), a neurotoxin produced by the dinoflagellate Karenia brevis, on polyethylene (PE) surfaces in relation to the presence of biofilms using radiolabeled ³H-PbTx-3. It was hypothesized that the presence of biofilms would enhance toxin retention on PE. Contrary to this hypothesis, results revealed significantly reduced adsorption of brevetoxin on biofilm-coated PE (0.035 ± 0.007 nmol mg^-1, p < 0.001) compared to virgin PE (0.59 ± 0.076 nmol mg^-1). Furthermore, toxin desorption from biofilm-coated PE occurred rapidly, with less than 20% activity remaining after 24 h, whereas virgin PE retained over 80% activity over the same period. Complete toxin depuration was not observed within one week under either condition. These findings demonstrate that biofilms not only reduce brevetoxin adsorption on PE but also accelerate desorption. Further research is needed to elucidate the broader ecological and health implications of microplastic-mediated biotoxin transport, albeit the results of this study suggest that biofilm-coated PE likely plays a minor role as vector for biotoxins in marine food webs, at least compared to its virgin counterpart.

Nitrogen dioxide (NO₂) in the air at concentrations exceeding permissible levels impacts environmental quality and human health. In addition, NO₂ is also a precursor to ozone and an agent that creates acid rain that affects the habitat of organisms. NO₂ emission inventories are the first and most important step, especially in urban or industrial production areas. This study assesses NO₂ emissions in Ho Chi Minh City (HCMC), Vietnam-a large city with high traffic and industrial activity but limited published emission data. Using the Lifetime-Modified Accumulation Method (LMAM), we analyze tropospheric NO₂ column data from the OMI/Aura satellite (2019-2024) to estimate spatial and temporal emission trends. The results showed an average emission rate of 6.56 × 10¹⁵ molecules cm⁻² h⁻¹ in 2019, decreasing to 5.79 × 10¹⁵ molecules cm⁻² h⁻¹ in 2020 due to the COVID-19 lockdown. Emissions were highest in urban and industrial areas and lowest in suburban areas. The LMAM model demonstrated a strong correlation with TROPESS Chemical Reanalysis (TCR) NO_x data (Spearman's r = 0.71 in 2019; r = 0.70 in 2020), confirming its reliability for trend analysis. Long-term trends reflect the socioeconomic impact: a sharp decline during the pandemic (2020-2021) followed by a recovery to 1.3 × 10¹⁶ molecules cm⁻² h⁻¹ in 2023-2024 when economic activities resume. This result can provide information on NO₂ emissions as a reference for future city emission control policies and inventory plans.

Arsenic (As) accumulation is a critical environmental concern in many developing countries due to its high toxicity and wide distribution. In the current investigation, As contents were estimated in soil, forage and cow's milk samples collected from rain-fed and groundwater-irrigated areas of Chakwal, Pakistan. The samples were subjected to wet digestion and examined for As contents using an atomic absorption spectrophotometer. As concentrations ranged from 2.28 to 10.57 mg kg^-1 in soil, 0.663 to 2.40 mg kg^-1 in forages, and 0.012 to 0.017 mg kg^-1 in milk. Among the forages Chenopodium album demonstrated the highest As contents at the groundwater-irrigated site, while Tribulus terresteris had the lowest As contents at the rain-fed site. All samples exhibited As levels below the permissible limits set by WHO. This study also found a significant positive correlation between As levels in soil and forages at both sites, while the correlation between forages and milk was negative and non-significant. All estimated pollution indices were below the threshold limit, indicating insignificant As contamination across study sites. However, Chenopodium album exhibited significantly higher pollution indices than other forage species (p < 0.05), signaling its enhanced bioconcentration potential.

The water in the coastal lagoons of the Tramandaí River Basin (TRB) in southern Brazil is affected by domestic, industrial, and agricultural effluents. The towns within the TRB experience significant population surges during peak vacation periods, which may further impact water quality. The micronucleus (MN) test is a useful tool for detecting genotoxic effects induced by pollutant mixtures and can serve as an indicator of water quality. This study aimed to evaluate the temporal variation in genotoxic potential and fecal contamination of water samples from four coastal lagoons within the TRB. Water sampling was conducted across four periods in the Cidreira, Fortaleza, Gentil, and Tramandaí lagoons. Specimens of Astyanax jacuhiensis were exposed to water samples and a negative control for 96 h in laboratory conditions. The frequencies of MN and other nuclear abnormalities (NA) were analyzed in the erythrocytes of the fish. Thermotolerant coliforms were assessed as an indicator of fecal contamination. Significant differences were noted during the summer season, with higher MN frequencies observed in the Gentil lagoon and increased NA frequencies in both the Gentil and Cidreira lagoons compared to the control group. During warmer periods, thermotolerant coliform counts exceeded the limits established by Brazilian legislation for recreational use in the Tramandaí, Gentil, and Cidreira lagoons. These results indicate temporal variations in fecal contamination and water genotoxicity in the TRB lagoons, with the highest values recorded in summer likely linked to increased tourism in the region.

Benzene is a highly volatile monoaromatic hydrocarbon and genotoxic carcinogen. In Brazil, it is considered a priority for the National Health System. However, although this compound is targeted by health surveillance in Brazil, scarce data are available on occupational or environmental exposure. This review contributes to an overview regarding benzene levels in the second-largest metropolis in Southeastern Brazil, Rio de Janeiro, and associated risks. A decreasing trend has been noted in the city of Rio de Janeiro, in the last decades, due to more stringent vehicular emission legislations and advances in vehicular technology, although adulterated gasoline is still a concern. Future actions regarding reductions of benzene emissions in the city include regulatory and surveillance programs concerning adulterated gasoline, substitution of raw materials to reduce benzene input to production processes, implementing changes in operating conditions to minimize benzene formation or volatilization and equipment modification to avoid benzene escaping into the environment. Finally, the increasing use and further construction of alternative transportation can significantly contribute to lowering benzene emissions in Rio de Janeiro and other metropolis worldwide and should be implemented as soon as possible.