Microarray platforms are a good approach for assessing biological responses to pollution as they enable the simultaneous analyses of changes in the expression of thousands of genes. As an omic and non-targeted methodology, this technique is open to unforeseen responses under particular environmental conditions. In this study, we successfully apply a commercial oligonucleotide microarray containing Mus musculus whole-genome probes to compare and assess the biological effects of living in a heavily polluted settlement, the Domingo Rubio stream (DRS), at the Huelva Estuary (SW Spain), on inhabitant free-living Mus spretus mice. Our microarray results show that mice living in DRS suffer dramatic changes in gene and protein expression compared with reference specimens. DRS mice showed alteration in the oxidative status of hepatocytes, with activation of both the innate and the acquired immune responses and the induction of chronic inflammation, accompanied by metabolic alterations that imply the accumulation of lipids in the liver (hepatic steatosis). The identified deregulated genes may be useful as biomarkers of environmental pollution.

Eight wheat cultivars were grown in soil amended with arsenate (Asⱽ) at a concentration of 15 mg As kg⁻¹ soil, with or without a triple super phosphate amendment of 40 mg P kg⁻¹ soil. All eight wheat cultivars accumulated higher As in stems/leaves (9–23 μg As g⁻¹) and chaff (9–22 μg As g⁻¹) compared with the grain (0.6–1.6 μg As g⁻¹). The As present in stems/leaves, grain and chaff was found as inorganic As species—Asⱽ or arsenite (Asᴵᴵᴵ). For most cultivars, increased P availability had minimal influence on As accumulation in chaff tissues. If this data is reflective of what occurs in situ, then As can accumulate in chaff at similar concentrations to stem and leaf tissues which are much higher than in grain. Further research is required to determine the risks of As accumulation in livestock products (meat and dairy) when fed with As-contaminated wheat chaff.

The elimination of herbicides in aquatic environment is influenced by various biotic or abiotic factors. Thus, efficient, more applicable, and flexible methods are in demand. Photodegradation has been applied to remove three main types of herbicides, phenylurea, triazine, and chloroacetanilide, from water, based on a series of TiO₂–reduced graphene oxide nanocomposites. Experimental results showed that the three types of herbicides could be mostly removed under simulated sunlight irradiation for 5 h with the as-prepared photocatalyst. Compared with pure TiO₂ or P25, the photodegradation efficiency has been markedly increased. Thus, the present work could promote a new strategy dealing with the pollution of herbicides in aquatic ecosystems.

Sudan dyes are widely used as coloring agents in various solvents, waxes, and polishes. However, the dyes are environmental contaminants and Sudan I is a weak carcinogen, and its removal from wastewater remains challenging. Here, we developed a new strategy for Sudan dye degradation for use in the non-alkaline conditions typically found in wastewater. By combing glucose oxidase (GOD) and horseradish peroxidase (HRP), we avoided the hydrogen peroxide-induced HRP damage and inactivation. Moreover, the GOD-HRP-coupled degradation of Sudan dyes were enhanced by the addition of different kinds of phenols. Systematic investigations were carried out to determine the optimal process parameters (i.e., phenol concentration, pH value, temperature, and enzyme dose) for degrading Sudan I with GOD and HRP. Also, this strategy could be applied to degradation of Sudan II and Sudan III. We were also able to co-express GOD and HRP in a prokaryotic-like polycistronic expression system in Pichia pastoris, based on the internal ribosome entry sites (IRES). Therefore, this fermented liquid containing GOD and HRP might be used in the future to degrade pollutants in weakly acidic conditions.

We investigated the effects of exposure to molluscicidal metaldehyde (MET) on golden apple snail (GAS) Pomacea canaliculata and Rhinella arenarum tadpoles by assessing mortality and/or other effects via: acute toxicity assays; B-esterase activities (acetilcholinesterase (AChE) and carboxilesterase (CbE)) and oxidative responses (glutathione-S-transferase (GST) and catalase (CAT)). The effect of sublethal concentrations of MET was also analysed by assessing biochemical changes and swimming parameters in tadpoles. The LC₅₀ value in P. canaliculata was as 0.50 mg L⁻¹ and in R. arenarun tadpoles, 229.7 mg L⁻¹ at 48 h. The intestine of MET-exposed P. canaliculata exhibited a significant reduction in CbE and CAT activities, but not in AChE activity; hepatopancreas of GAS showed a decreased GST activity decreased with respect to control individuals. In addition, a significant reduction of CbE activities was detected in R. arenarum tadpoles exposed to MET, and AChE presented lower values than the control but without statistical differences. Antioxidant enzymes (GST and CAT) were significantly reduced in tadpoles exposed to MET compared with the control group. In addition, MET had a significant effect on the swimming behaviour of R. arenarum. Finally, since amphibian tadpoles and P. canaliculata often co-occur, other native amphibian species should be studied to elucidate the ecological risk of MET to amphibian populations.

In this study, a novel water-insoluble zinc–Schiff base complex, Zn(II)-N-salicylaldehyde-2-hydroxyanil (abbreviated as Zn-salen), was synthesized and used as a heterogeneous photocatalyst for the activation of molecular oxygen to degrade organic pollutants in aqueous solution under visible light irradiation (λ ≥ 420 nm). The catalyst was characterized by FT-IR, UV–vis spectroscopy, NMR, and MS analysis. Zn-salen displays a selective adsorption and degradation of electropositive organics, such as rhodamine B (RhB), methylene blue (MB), and o-phenylenediamine (OPD). After using cetyl trimethyl ammonium bromide (CTAB) to change sulforhodamine B (SRB) into RhB-like electropositive molecule, the degradation of SRB increased up to 96 % after 4 h of irradiation, indicating that the selectivity arises from the charge interaction between the catalyst and substrates. Zeta potential of Zn-salen also reveals that the catalyst surface is negatively charged in neutral solution, suggesting that the catalyst is selective towards positively charged substrates due to an electrostatic force of attraction. The photocatalyst was active within a wide pH range (pH 3–11) and chemically stable and can be reused over 10 times. In addition, ¹O₂ and O₂·⁻ were involved in photocatalytic degradation but O₂·⁻ appears to be the primary reactive oxygen species.

Research and routine analysis laboratories produce sizeable amounts of residues as a result of experiments and by-products of chemical reactions. An example of that is soil analysis, in which a sulfochromic solution is used for the determination of organic matter content. This solution contains sodium dichromate and sulfuric acid, reagents that oxidize the soil’s organic fractions and contribute to the presence of chromium in laboratory residues discharged into the environment. In an attempt to find solutions to environmental problems, the aim of the present study was to quantitatively and qualitatively characterize chromium-contaminated residues generated during soil analysis. Therefore, management methods were proposed in order to recover chromium in its trivalent form (Cr³⁺) by precipitation. The use of biochemical oxygen demand, chemical oxygen demand, nitrogen, phosphorus, and metals to characterize the samples revealed the presence of 16.76 g L⁻¹ of total chromium, with 4.19 g L⁻¹ of Cr(VI). By means of ozonation, 68 % of the chromium was converted to liquid form and, after being reduced with bisulfite, it was turned into chromium sulfate (III). The remainder, 32 %, was kept with the other metals present in the solid form (sludge).

Fluoride intake, fluorosis, and dental caries could affect quality of life and disease burden worldwide. As a part of the National and Sub-national Burden of Disease Study (NASBOD) in Iran, we conducted a systematic review to evaluate province-year-specific mean drinking water fluoride concentrations and prevalence of fluorosis and of decayed, missed, and filled teeth (DMFT) in Iran from 1990 to December 2015. We did electronic searches of all English and Persian publications on PubMed, ScienceDirect, Google Scholar, and Iranian databases. Results revealed that the weighted mean drinking water fluoride concentration in Iran from 1990 to 2015 has been about 0.65 ± 0.38 mg/l. However, based on the WHO guideline value (1.50 mg/l) and the maximum permissible Iranian national fluoride standard (1.40 to 2.40 mg/l depending on the region's climate), there have been some regions in Iran with non-optimum fluoride concentrations in their drinking water (up to 7.0 mg/l). Overall, concentrations have been higher in southern parts of Iran and in some areas of Azerbaijan-e-Gharbi Province in the northwest and lower in the rest of the northwest and central parts of Iran. In addition, some hotspots have been found in Bushehr Province, southwest of Iran. The highest prevalence of dental flourosis has been reported in normal index while the lowest prevalence has been expressed in severe index. The lowest DMFT (about 0.1) was in Arsanjan City in Fars Province, and the highest (about 6.7) was for Najaf Abad City in Isfahan Province. Prevalence of fluorosis has been rather high in studied areas of Iran (e.g. 100 % in Maku City in Azarbaijan-e-Gharbi Province), and there was discrepancy for DMFT, but a lack of studies renders the results inconclusive. Further studies, health education and promotion plans, and evidence-based nutrition programs are recommended.

Pharmaceutically active compounds (PhACs) are common contaminants found in surface and groundwaters, often due to their inefficient removal from wastewater treatment plants. One way in which these compounds can be removed is via aerobic cometabolism, a process that involves oxygenases produced by microorganisms. Limited work has been done examining the efficacy of cometabolism in the removal of PhACs. Therefore, the aim of this work was to investigate the use of an alkane (pentane) in the aerobic cometabolic transformations of paracetamol, ibuprofen, naproxen, diclofenac, and nimesulide. Both paracetamol and ibuprofen (single aromatic compounds) were readily transformed, with net specific biodegradation rates equal to 1.6 and 3.2 μmol/gcₑₗₗ/day, respectively. Conversely, the two aromatic ring PhACs showed slower (naproxen and nimesulide) or no transformation (diclofenac). In addition, four of the tested PhACs (ibuprofen, paracetamol, naproxen and nimesulide) did not inhibit pentane uptake.