Polychaete worms can biotransform polycyclic aromatic hydrocarbons (PAHs) in environments, and the cytochrome P450 (CYP) enzyme plays an important role in this process. Herein, a novel cytochrome P450 gene was identified and characterized from the polychaete worm Perinereis aibuhitensis. The full-length cDNA, which is named CYP4V82, is 1709 bp encoding a protein of 509 amino acids and has high similarity to CYP4V. The expression levels of CYP4V82 and CYP4BB4 (a CYP gene identified from P. aibuhitensis in a previous study, Chen et al. Mar Pollut Bull 64:1782–1788, 2012) exposure to various concentrations of benzo[a]pyrene (B[a]P) (0.5, 2, 4, and 8 μg/L) and same mass concentrations of fluoranthene (Flu, 3.2 μg/L), phenanthrene (Phe, 2.9 μg/L), B[a]P (4.0 μg/L) were detected to identify the function of the CYP4 family in P. aibuhitensis. Compared with CYP4BB4, CYP4V82 mRNA was minimally expressed on day 7 but highly sensitive on day 14. Notably, the expression levels of CYP4V82 and CYP4BB4 were relatively different in short-term responses to PAHs with different benzene rings of the same concentration. The expression of CYP4V82 in the B[a]P group was the highest, while that of CYP4BB4 in the Phe group was relatively higher than the two other groups. These findings suggest that PAHs are associated with the induction of CYP4V82 and CYP4BB4 expressions in P. aibuhitensis, which may have different efficiencies in the detoxification of PAHs.

The indigo blue dye is widely used in the textile industry, specifically in jeans dyeing, the effluents of which, rich in organic pollutants with recalcitrant characteristics, end up causing several environmental impacts, requiring efficient treatments. Several pieces of research have been conducted in search of effective treatment methods, among which is electrocoagulation. This treatment consists of an electrochemical process that generates its own coagulant by applying an electric current on metallic electrodes, bypassing the use of other chemical products. The purpose of this study was to evaluate the potential use of iron slag in the electrocoagulation of a synthetic effluent containing commercial indigo blue dye and the effluent from a textile factory. The quantified parameters were color, turbidity, pH, electrical conductivity, sludge generation, phenol removal, chemical oxygen demand (COD), and total organic carbon (TOC). The electrocoagulation treatment presented a good efficiency in removing the analyzed parameters, obtaining average removal in the synthetic effluent of 85% of color and 100% of phenol after 25 min of electrolysis. For the effluent from the textile factory, average reductions of 80% of color reaching 177.54 mg Pt CoL⁻¹, 91% of turbidity reaching 93.83 NTU (nephelometric turbidity unit), 100% of phenol, 55% of COD with a final concentration of 298.8 mg O₂ L⁻¹, and 73% of TOC with a final concentration of 56.21 mg L⁻¹, in 60 min of electrolysis. The reduced time for removal of color and phenolic compounds in synthetic effluent demonstrates the complexity of treating the real effluent since to obtain removals of the same order a 60-min period of electrolysis was necessary. The results obtained demonstrate the potential of using iron slag as an electrode in the electrocoagulation process in order to reuse industrial waste and reduce costs in the treatment and disposal of solid waste. Thus, the slag can be seen as an alternative material to be used in electrocoagulation processes for the treatment of effluents from the textile industry under the experimental conditions presented, its only limitation being the fact that it is a waste and therefore does not have a standardization in the amounts of iron present in the alternative electrodes.

Long-term exposure to organic solvents is known to affect human health posing serious occupational hazards. Organic solvents are genotoxic, and they can cause genetic changes in the exposed employees' somatic or germ cells. Chemicals such as benzene, toluene, and gasoline induce an excessive amount of genotoxicity results either in genetic polymorphism or culminates in deleterious mutations when concentration crosses the threshold limits. The impact of genotoxicity is directly related to the time of exposure, types, and quantum of solvent. Genotoxicity affects almost all the physiological systems, but the most vulnerable ones are the nervous system, reproductive system, and blood circulatory system. Based on the available literature report, we propose to evaluate the outcomes of such chemicals on the exposed humans at the workplace. Attempts would be made to ascertain if the long-term exposure makes a person resistant to such chemicals. This may seem to be a far-fetched idea but has not been studied. The health prospect of this study is envisaged to complement the already existing data facilitating a deeper understanding of the genotoxicity across the population. This would also demonstrate if it correlates with the demographic profile of the population and contributes to comorbidity and epidemiology.

The partial or full replacement of natural aggregates with recycled ones can lessen the harmful effects of concrete industry on the environment. Despite offering sustainability benefits, recycled aggregate concrete (RAC) is inherently brittle under tension similar to natural aggregate concrete (NAC). The present study aimed to enhance the ductility of plain RAC by using hybrid fibers. The effect of single and hybrid fibers was studied on the flexural behavior (flexural strength, flexural toughness, residual strength), splitting tensile strength, and compressive strength of RAC. Polypropylene fiber (PPF) and hooked steel fiber (HSF) and hybrid fiber combination (0.85% HSF + 0.15% PPF) were used in RAC and NAC at a 1% volume fraction of concrete. The results showed that RAC with 1% PPF performed poorly compared to the RAC with 1% HSF. RAC incorporating 1% HSF or hybrid HSF-PPF fibers showed overall better performance than plain NAC. A substantial increment in the tensile and flexural strength of RAC was observed with the incorporation singular HSF and hybrid HSF-PPF. Hybrid fibers have higher efficiency than singular HSF in both RAC and NAC. Residual strength, flexural strength, and flexural toughness of RAC with HSF and hybrid fibers were notably higher compared to the conventional plain NAC. The addition of 0.85% HSF + 0.15% PPF is beneficial to the imperviousness of concrete, and it reduced the water absorption capacity of RAC by 6.4%.

In this study, the high-gravity technique is used to intensify the heterogeneous catalytic ozonation with activated carbon (AC) as the catalyst for removal of phenol from wastewater in a rotating packed bed (RPB), and the effects of high-gravity factor, inlet O₃ concentration, liquid–gas ratio, and initial pH on the degradation and mineralization of phenol at room temperature are investigated. It is revealed that the degradation rate of phenol reaches 100% at 10 min and the removal rate of total organic carbon (TOC) reaches 91% at 40 min under the conditions of high-gravity factor β = 40, inlet O₃ concentration = 90 mg·L⁻¹, liquid flow rate = 80 L·h⁻¹, and initial pH = 11. Compared with the bubbling reactor (BR)/O₃/AC and RPB/O₃ systems, the mineralization rate of phenol by the RPB/O₃/AC system is increased by 24.78% and 34.77%, respectively. Free radical quenching experiments are performed using tertiary butanol (TBA) and benzoquinone (BQ) as scavengers of ·OH and O₂⁻, respectively. It is shown that the degradation and mineralization of phenol are attributed to the direct ozonation and the indirect oxidation by ·OH generated from the decomposition of O₃ adsorbed on AC surface, respectively. ·OH and O₂·⁻ are also detected by electron paramagnetic resonance (EPR). Thus, it is concluded that AC-catalyzed ozonation and high-gravity technique have a synergistic effect on ·OH initiation, which in turn can significantly improve the degradation and mineralization of organic wastewater.

Cleaning products are mixtures of many chemical ingredients that are known to contain sensitizers, disinfectants, and fragrances, as well as strong airway irritants which associated with lower respiratory tract and asthma symptoms. The aim of this study is to assess the prevalence and possible risk factors of occupational asthma and its effect on quality of life among workers in detergent and cleaning products industries in El Asher men Ramadan city. This cross-sectional study was conducted on 780 workers. All participants were personally interviewed at their workplaces and were subjected to a questionnaire regarding sociodemographic, work characteristics and asthma symptoms, clinical examination, chest X-ray, spirometer, and bronchodilator test. The prevalence of occupational asthma among the studied workers was 35.4%. Multivariate logistic regression analysis revealed that female gender [odds ratio 1.397; 95% CI 1.09–1.96], manually working participants [odds ratio 3.067; 95% CI 1.72–5.46], and history of atopy [odds ratio 1.596; 95% CI 1.09–2.33] were risk factors for development of occupational asthma. The total mean score of asthma-specific quality of life was significantly lower in asthmatic (5.10 ± 0.49) than non-asthmatic workers (5.89 ± 0.46) (P < 0.01) indicating impairment of quality of life among asthmatic group. Workers in detergent and cleaning products industry are at higher risk for developing occupational asthma that adversely affects their general health and quality of life.

2,4,6-Trichlorophenol (2,4,6-TCP) is a common waste among the resulting chlorophenols generated in the production of common products classified as an extremely toxic, mutagenic, carcinogenic and highly persistent xenobiotic in the environment. To evaluate the impact of 2,4,6-TCP in aquatic systems, the catfish species Clarias batrachus has been selected to test its toxicity due to its high market value and consumption in India. Here is presented the impact of this compound on different physiological parameters of fish: haematological parameters (haemoglobin, total erythrocyte count, total leucocyte count and mean corpuscular haemoglobin), biochemical parameters (total serum protein and total serum glucose), growth and reproductive parameters (condition factor, hepatosomatic index, maturity index, specific growth rate, growth hormone, 17β-estradiol and testosterone), exposed to two concentrations of 2,4,6-TCP (0.5 mg/L and 1 mg/L — 1/10th and 1/20th of the LC₅₀) for a period of 15, 30 and 45 days. The results showed that C. batrachus even when exposed to the lower concentration (0.5 mg/L) for the shortest time (15 days) negatively impacted the organism in all the assessed parameters. This was highlighted by the Integrated Biomarker Response index (IBR), showing worse scores for the treatments (up to 20 × worse than the control). This work highlights the importance of continued research on the impact of 2,4,6-TCP, on an important commercial, supported by the high environmental persistence of this compound that can reach the same range of tested concentrations.

Rhizosphere bacteria, for example, rhizobia, can play several roles, and one of the most important, the protection of plant roots against toxic conditions and other environmental stresses. In this work, the action of Cu²⁺ and Cr⁶⁺ on cell growth and EPS production of four strains of rhizobia, Rhizobium tropici (LBMP-C01), Ensifer sp. (LBMP-C02 and LBMP-C03), and Rhizobium sp. LBMP-C04, were tested. The results confirmed the strong effect of Cu²⁺ and Cr⁶⁺ on bacterial exopolysaccharides (EPS) synthesis, and how cells can adsorb these metals, which may be a key factor in the interactions between rhizosphere bacteria and host plants in heavy metal–contaminated soils. Here, we emphasize the importance of proving the potential of treating bacterial cells and their extracellular EPS to promote the bio-detoxification of terrestrial and aquatic systems contaminated by heavy metals in a highly sustainable, economic, and ecological way.

Investigation of ZnO nanoparticles (nano-ZnO) and graphene quantum dots (GQDs) toxicology on dinoflagellate Gymnodinium helps to understand the effects of different surface characteristic nanoparticles on marine algae. The growth and biological responses of the algae exposed to 1, 10, 20 mg L⁻¹ nano-ZnO and GQDs in f/2 media were explored. Nano-ZnO showed slight effects on algal cells growth, while the growth inhibition rates of Gymnodinium increased as GQDs concentration increasing. Both nanoparticle treatments induced accumulation of reactive oxygen species and activated intracellular antioxidant defensive system, including SOD and ATPase, which were related to the two nanoparticles concentration. Under combined exposure of nano-ZnO and GQDs, the inhibitory effects decreased compared to the single GQDs and showed antagonistic effect. The addition of nano-ZnO could decrease the toxicity of GQDs due to aggregation and sedimentation interaction between nanoparticles. The morphologic change of the cells observed by SEM proved that nanoparticles adsorbed onto the cell surfaces and caused the cell shrinkage.