Environmental Chemistry and Ecotoxicology最新文献

Environmental ubiquity of pharmaceuticals has stimulated a lot of societal and global concerns. The occurrence of pharmaceuticals in the environment differs from country to country depending on the extent of consumption and monitoring. Most studies reporting the occurrence of pharmaceuticals are conducted in coastal regions with numerous articles and reviews reported in developed countries. The current review reports the occurrence of pharmaceuticals in inland waters with major focus devoted to developing countries in Africa and Asia. The focus was further dedicated to sources and distribution mechanisms, which contribute greatly to their ubiquity in the environment. Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are the most reported pharmaceuticals in African waters. For example, an antibiotic (sulfamethoxazole) was detected in more than four African countries with highest concentrations reaching 53.8–56.6 μg L⁻¹ detected in Kenya and Mozambique. Furthermore, highest concentrations of amoxicillin ranging from 0.087–272.2 μg L⁻¹ were detected in Nigeria. Ibuprofen, which is NSAID was detected at highest concentrations reaching 67.9 and 58.7 μg L⁻¹ in Durban city and Msunduzi River (KwaZulu-Natal, South Africa), respectively. However, highest concentration of antiretroviral drug (lamivudine) up to 167 μg L⁻¹ was found in surface water samples collected from Nairobi and Kisumu city, Kenya. In Asian countries, antibiotics were detected at highest concentration reaching 365.05 μg L⁻¹ in surface water samples. However, concentrations of other pharmaceuticals were comparably below the concentrations detected in African environmental waters. Health risks associated with their fate in the environment are critically reviewed. Sample preparation techniques and analytical instruments necessary for the occurrence studies were also reviewed. The concluding remarks were based on deliberating the possible future prospects within the research expertise.

Increasing industrialization leads to enhanced level of pollutants in wastewater that ultimately degrade the environment. Fucus vesiculosus, brown algae was utilized as bioadsorbent for elimination of cationic dyes from aqueous solution. The removal efficiency of F. vesiculosus seaweed bioadsorbent (FVSB) was investigated as 98.71% for Methylene Blue (MB) and 96.68% for Rhodamine B (RB). Various adsorption parameters such as adsorbent dosage, concentration, contact time, temperature and pH have been discussed in detail. The maximum adsorption capacity of MB and RB was 200 mg/g and 166.66 mg/g, respectively. The process of spontaneous and endothermic adsorption follows Langmuir adsorption isotherm and experimental data fitted well into pseudo-second-order kinetics. No remarkable loss in removal efficiency was observed after regeneration and recycling the bioadsorbent for 5 times. The bioadsorbent was also considered for removal of color from environmental sample representing significant result. FVSB could be considered as a suitable bio-adsorbent for removal of organic dyes with high efficacy as an eco-friendly and sustainable approach for water remediation.

Chromium (Cr) ions, discharging from different industrial activities, especially from leather tanning industries, are becoming a major threat for the environment and human health. Therefore, elimination of chromium ions from industrial effluents should be addressed with great attention. Hence, this study was conducted for evaluating the possibilities of using an agricultural waste “flax” to eliminate Cr (III) ions from aqueous solutions. In order to assess the effects of various experimental parameters (i.e., contact time, pH, adsorbent amount, initial chromium ion concentration and particle size) on Cr (III) ions adsorption process, the batch adsorption study was conducted. This study revealed that adsorption of Cr (III) ions by flax required 420 min to reach equilibrium. On the other hand, the maximum (~70%) Cr (III) ions removal was observed at pH value of 2.0. The desorption efficiency with 0.5 M KOH was found to be 90%. The Langmuir and Freundlich isotherms models were in better correlation with experimental data, according to equilibrium studies. Kinetic experiments showed that the first order kinetics with a rate constant of 0.01 min⁻¹. Use of real wastewater sample became a great success for removing of Cr (III). This result suggests that the flax plant has the potentiality to become an effective and environmentally friendly economical adsorbent for the removal of Cr (III) ions significantly from waste water.

Palk Bay is a marine protected area with a sensitive ecosystem like coral reefs, seagrass meadows, and mangroves with rich biodiversity. Observations indicate that these ecosystems are at risk from organic contaminants like petroleum hydrocarbon. In view of this Total Petroleum Hydrocarbons (TPHs) were measured in the surface sediments from the Palk Bay. Sediment samples were extracted in n-hexane and quantified using a fluorescence spectrophotometer. The concentrations of TPH varied from 0.78 ± 0.28 to 2.70 ± 0.84 μg/g (wet wt.) and were relatively higher in southern region than the northern. Higher TPH levels at the Bay are attributed to the anthropogenic activities and hydrodynamic characteristics. Analysis of sediment texture and organic carbon can provide insights into the distribution of TPH. Significant correlation was found between the sediment texture with TPHs and TOC. The average proportions of sediment grain sizes were 88.39 ± 3.92% of sand, 70.54 ± 2.24% of loamy sand, 62.22 ± 3.76% of sandy loam, and 29.58 ± 5.59% silt loam. Silt and clay of sediment have more capacity to hold the TPH because of their particle size. This is in consonance with the observed TOC levels in the range of 0.11 ± 0.05% and 2.78 ± 1.12% (dry weight). TPH concentrations are observed within the permissible limits and the data may serve as baseline information for identifying pristine coastal ecosystems like Palk Bay.

Although numerous studies have investigated environmental occurrence, human exposure, and toxic effects of bisphenol analogues including bisphenol A (BPA), little is known about closely related chemical classes namely, bisphenol A diglycidyl ethers (BADGEs) and novolac glycidyl ethers (NOGEs), which are widely used in a variety of industrial and consumer products. In this review, we compiled available information on production and usage, analytical challenges, dietary and non-dietary sources of exposure, occurrence in human and environmental matrices, toxicity, and regulations on BADGEs and NOGEs. Human exposure to BADGEs and NOGEs is widespread, with exposure doses in the range of several hundreds of nanograms (ng) to few micrograms (μg) per kilogram (kg) body weight (bw) per day (d) from diet and <10 ng/kg bw/d from inhalation of indoor air and indoor dust ingestion. Canned foods and beverages contain BADGEs and NOGEs at concentrations on the order of several tens to hundreds of nanogram (ng) per g and in some cases up to several thousand ng per g. The highest reported concentration of BADGEs thus far was in canned fish at 12.6 mg/kg. In indoor dust samples, a BADGE concentration of up to 63.2 mg/kg was reported. Among five derivatives of BADGEs analyzed in several studies, BADGE·2H₂O and BADGE·HCl·H₂O were predominant in indoor dust and environmental samples. In human adipose tissue, a concentration of up to 4500 ng/g bisphenol F diglycidyl ether (BFDGE), a building block of NOGE, was reported. The epoxide moieties of BADGEs and NOGEs impart high reactivity of these chemicals, which exhibit toxicity through endocrine disruption, reproductive effects and genotoxicity. Formation of adducts/conjugates and reaction products of BADGEs with DNA and protein was reported, although little is known about the magnitude of their occurrence and toxicity. Regulatory framework for these chemicals is mainly focused on migration limits in canned foods. Despite their high production and widespread usage, studies on environmental transport, toxicity and fate are still limited and further studies should focus on adducts/biotransformation products, toxicological mechanisms, as well as ecological and human health risks of BADGEs and NOGEs.

The elevated concentration of hydrogen peroxide (H₂O₂) due to natural and anthropogenic causes is a significant bane to marine and coastal organisms, as it has a prolonged half-life and can inject across lipid bilayers and interfere with aquatic redox processes. The present assessment aimed to determine the acute effect of H₂O₂ on larval development of the Mediterranean mussel Mytilus galloprovincialis and to observe the oxidative stress (OS) responses, including genotoxicity and neurotoxicity in the clam Ruditapes philippinarum. Two experiments were performed, in which (a) mussel embryos were exposed to the consecutive dilution (0.0, 0.05, 0.5, 5.0, 50.0 and 500.00 μM) of H₂O₂ for 48 h and (b) adult clams were exposed to similar concentrations - of this reactive oxygen species (ROS) for 21 days. Incremental H₂O₂ significantly retarded the growth of mussel larvae; the percentage of malformed larvae increased with increasing toxicant concentration (p < 0.01, and r = 0.884). H₂O₂ also induced oxidative stress (OS) in clams, indicated by the activation/inactivation of antioxidant enzymes (GST, GPx, and GR) with a significant rise in lipid peroxidation (LPO) in the digestive gland tissues of the clams (p < 0.05). No genotoxicity or neurotoxicity on R. philippinarum were evident after chronic exposure. The battery of responses (organismal and cellular parameters) showed embryotoxicity and sublethal effects on bivalves, which confirmed their suitability for assessing the effect of H₂O₂ mediated OS responses in the marine environment.

The purpose of this study was to determine the concentrations and contamination level of heavy metals and metalloid (i.e., Zn, Fe, Cu, Mn, Pb and As) in sediment samples taken from a thermal power station's 5 km buffer area (Bandel thermal power station-BTPS) in West Bengal, India. The atomic absorption spectrophotometer (AAS) was used to determine the presence of heavy metals in soil samples. Heavy metal and metalloid concentrations such as Zn, Fe, Cu, Mn, Pb and As were studied using various contamination and pollution-related indexes such as geo-accumulation index, enrichment factor, contamination factor, contamination degree, modified degree of contamination index, and pollution load index, and spatial distribution was presented using interpolation technique. An ecological risk index for all metals and a forecasted ecological risk index are also used to investigate the impact of heavy metals on biological elements in the soil. ANOVA and the Kruskal-Wallis test were among the multivariate statistical procedures used. Hierarchical cluster analysis was used to estimate the spatial similarity of sample locations, and Pearson's correlation was used to determine the relationship between different metal concentrations and soil physico-chemical parameters. Almost all of the sample sites had soils of very good to medium quality, according to the study. All heavy metals at this research site, with the exception of arsenic and lead, behave as plant micronutrients. Furthermore, no heavy metal band, with the exception of As, had a consistent concentration. Almost all of the sampling locations had extremely low to very low levels of pollution.

Among the fossil fuels, petroleum is more valuable to several businesses due to the production of extensive assortments of finished products, making it a pivot natural resource in the development of the world's economic system via energy usage which are 32% for Europe and Asia, Middle East (53%), South and Central America (44%), Africa (41%), and North America (40%). The most apparent air pollution impediments of the petroleum industry are concentrated in its refining segment. Various pollutants are discharged from different phases of the petroleum refining process. This article intends at publicising dispersed information and also close the knowledge gap in the area. It offers an update on processes involved in petroleum refining, air pollution sources, impacts, reviews on findings, and highlights from different scientific reports on air quality and management. It is paramount that establishing as well as imposing environmental protocols in the petroleum refining industry are crucial for controlling air pollution to protect flora and fauna including human beings. Moreso, the ambient air quality should be managed methodically in developing countries where increased energy demands, industrialization, and overpopulation is leading to increased emissions and reduced air value.

The impact of sub-lethal concentrations of glyphosate (Isopropylamine salt - H₂NCH(CH₃)₂) an active ingredient in Roundup® herbicides on growth and haematology of African catfish (Clarias gariepinus) were evaluated under aquatic ecological envirornment. Uncontrolled discharge of glyphosate from agricultural farm land to aquaculture facilities necessitated the study. Sub-lethal concentrations 0.30 mg/l, 0.50 mg/l, 0.70 mg/l and 1.40 mg/l were established after series of range finding tests. Weight (g) and length measurement (cm) were taken on biweekly basis to monitor growth. Behavioural responses to treatment during the range finding tests includes: erratic swimming, loss of balance, mucous secretion, discolouration, hanging on water surface and inactivity. Blood parameters analyzed were Red Blood Cell (RBC), Haemoglobin content (Hb), Packed Cell Volume (PCV), White Blood Cell (WBC), Platelet (PLT), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC). Automated haematology analyser was used to determine the blood parameters. The physico-chemical parameters monitored were temperature, pH, Dissolved Oxygen and Electrical Conductivity. Thermometer, pH meter, dissolved oxygen meter and Electrical conductivity meter respectively were used. The findings of the study demonstrated that exposure for 60 days to the herbicide “glyphosate” at sub-lethal doses of 0.30 mg/l, 0.50 mg/l, 0.70 mg/l and 1.40 mg/l were toxic to Clarias gariepinus and this toxicants were dose-dependent.There was significant difference (P < 0.05) in growth among the treatments. The best growth was recorded in the control (0.00 mg/l) while poorest growth was recorded in 1.40 mg/l. The findings in this study showed that 0.30 mg/l to 1.40 mg/l of the toxicants were harmful to Clarias gariepinus. The report therefore recommended examination of lower concentrations (<0.30 mg/l) in future study to establish the limit beyond which glyphosate should not be allowed in aquaculture system.

Three fish species (Schizothorax richardsonii, Salmo trutta and Neolissochilus hexagonolepis) were collected from Punatsang Chhu river and sample tissues of muscles and gills were analyzed for Al, As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Se, Sr and Zn using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Principal Component Analysis (PCA) for each species grouped elements with higher concentration in gills compared to muscle tissues. The Man-Whitney test revealed significant difference between tissues sources and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn in S. richardsonii, Al, Ba, Co, Fe, K, Mn, Ni, Sr and Zn in S. trutta and Al, Ba, Co, Cr, Fe, K, Mn, Sr and Zn in N. hexagonolepis. The Kruskal-Wallis test for inter-species variation revealed significant difference in concentration of As, Cr, Cu, Fe, Mn, Ni and Zn in muscle tissues and Ba, Cr, Cu, Mn, Sr and Zn concentrations in gills of three species. Spearman correlation between levels of elements and fish size (weight and length) revealed positive and negative relationships for concentrations of As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, Sr, and Zn and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn respectively, both at p < 0.001 and p < 0.005.