Naphthenic acids (NAs) are toxic constituents of oil sands process-affected water (OSPW) which is generated during the extraction of bitumen from oil sands. NAs consist mainly of carboxylic acids which are generally biorefractory. For the treatment of OSPW, ozonation is a very beneficial method. It can significantly reduce the concentration of NAs and it can also convert NAs from biorefractory to biodegradable. In this study, a factorial design (2⁴) was used for the ozonation of OSPW to study the influences of the operating parameters (ozone concentration, oxygen/ozone flow rate, pH, and mixing) on the removal of a model NAs in a semi-batch reactor. It was found that ozone concentration had the most significant effect on the NAs concentration compared to other parameters. An empirical model was developed to correlate the concentration of NAs with ozone concentration, oxygen/ozone flow rate, and pH. In addition, a theoretical analysis was conducted to gain the insight into the relationship between the removal of NAs and the operating parameters.

Determining the environmental risk of metals requires an in-depth understanding of the environmental matrices composition, which currently also includes the presence of manufactured metallic nanoparticles (NPs) usually, stabilized by a polymer surface coating. As a consequence, is necessary to take into account effects of the NP core, the polymer surface coating and their mutual interaction as well as with other environmental components. The release of metal ions from metallic NPs is a well-known outcome, however, the effect of the presence of the NP polymer coating in the NPs solubilization mechanism is not well understood. In this study the dynamic speciation of Cd and Pb in presence of a polyacrylic acid (PAA)-stabilized CdTe/CdS NP was quantified by scanned stripping chronopotentiometry (SSCP). It was found that although the NP solubility was 5.8× larger at pH 8.5 than at pH 6.0, the amount of free Cd ions was much smaller (2.4 % at pH 8.5 vs. 57 % at pH 6.0). The concentration of free Cd and Pb ions in solution was larger in presence of the PAA-shells than when in presence of the same amount of polymer but when this is at the surface of the NP. This effect is attributed to the metal ions interaction with the particle itself. The effect is notably larger for Pb ions and might results from the exchange of Cd by Pb ions at the particle surface since PbS is less soluble than CdS.

Air pollution in cities is a serious environmental problem especially in the developing countries. We examined the associations between gaseous pollutants and hospitalizations for chronic obstructive pulmonary diseases (COPD) among people living in Tabriz, a city in north western of Iran. We used the approach proposed by the World Health Organization (WHO) using the AirQ 2.2.3 software developed by the WHO European Center for Environment and Health, Bilthoven Division. To assess human exposure and health effect, data were used for ozone as a1h average; for nitrogen dioxide and sulfur dioxide as daily average concentrations. The association between air pollution and chronic obstructive pulmonary disease (COPD) was assessed using AirQ 2.2.3 model. The results of this study showed that 3 % (95 % CI 1.2–4.8 %) of HA COPD were attributed to O₃concentrations over 10 μg/m³. Also, 0.9 % (95 % CI 0.1–2.2 %) and 0.4 % (95 % CI 0–1.1 %) of HA COPD were attributed to NO₂and SO₂concentrations over 10 μg/m³, respectively. For every 10 μg/m³increase in O₃, NO₂, and SO₂concentrations, the risk of HA COPD increase to about 0.58, 0.38, and 0.44 %, respectively. We found significant positive associations between the levels of all air pollution and hospital admissions COPD. Otherwise, O₃, NO₂, and SO₂have a significant impact on COPD hospitalization.

In the present study, tissue samples of patients with cancerous and non-cancerous prostate were analyzed for their Se, Ni, and Ca contents. Possible relationship between Se, Ni, and Ca concentrations and some parameters including preoperative prostate-specific antigen (PSA) levels, histopathological neurovascular invasion, extra-capsular extension, seminal vesicle invasion, positive surgical margins, PSA relapse after radical prostatectomy, and total Gleason scores were obtained. Inductively coupled plasma (ICP) optical emission spectrometry and ICP-mass spectrometry instruments were used for the determination of analytes interested. All the system parameters in digestion and measurement steps were optimized to obtain efficient digestion and sensitive measurements. There was no statistically meaningful difference observed in the concentration of selenium in cancerous and benign prostatic tissues (p = 0.347) while nickel levels in cancerous tissues were observed as significantly lower than benign tissues (p < 0.001). In addition, calcium concentration in cancerous tissue samples were found to be statistically lower than those in benign tissues (p < 0.001) with mean values of 657 and 1,431 mg/kg, respectively.

The concentration changes of 18 different polycyclic aromatic hydrocarbons (PAHs) in two different biochars were assessed after (1) chemical oxidative treatment with a solution of H₂O₂ and Na₂S₂O₈, (2) exposure to sunlight with intermittent wetting, and (3) exposure to sunlight with intermittent wetting after mixing in ZnO and Na₂S₂O₈. Chemical oxidative treatment of biochars derived from gasified wood biochar and a gasified wood/Arundo donax mixture led to decreases in six-ring PAHs, but overall significant increases in measured PAH concentration sums for both biochars (from 225 ± 7 to 312 ± 18 μg g⁻¹ for wood-derived and 165 ± 3 to 244 ± 7 μg g⁻¹ for mixture-derived). Sunlight exposure of the mixture-derived biochar led to increases in some three- and four-ring PAHs, but overall decreases in summed PAH concentrations (165 ± 3 to 60 ± 1 μg g⁻¹ with wetting only and 165 ± 3 to 41 ± 4 μg g⁻¹ when Na₂S₂O₈ and ZnO were included). The mass losses in the sunlight-exposed samples primarily were due to losses of low molar mass (two-ring) PAHs, though high molar mass (five- and six-ring) PAH concentrations also decreased. This result implies sun and rain exposure to biochar, prior to agricultural application, will help reduce potential PAH soil contamination from the biochar.

In urban areas, primary and secondary organic aerosols are typically considered to originate from vehicular traffic emissions. However, industrial emissions within or in the vicinity of urban areas may also be significant contributors to carbonaceous aerosol concentrations. This hypothesis was tested and validated in two urban areas in Spain. The observed unusual dominance of organic carbon (OC) over elemental carbon (EC), the analysis of the variability of OC, EC and OC/EC and their correlation with transport patterns suggested the presence of OC sources associated with industrial activities. A methodology based on chemical speciation of particulate matter (PM) followed by the application of receptor modelling techniques allowed for the identification of the specific industrial sources of OC, which were linked to primary OC emissions from a grain drying plant (cereal) and to secondary OC formation from paper production activities (paper mills), as well as from urban sources and biogenic emissions. This work presents an integrated approach to identifying and characterizing of industrial sources of carbonaceous aerosols in urban areas, aiming to improve the scarce body of literature currently available on this topic.

Cadmium (Cd) is an important toxic chemical due to its increasing levels in the environment and its resulting accumulation in humans and animals. The present study was performed to evaluate the long-term effects of low doses of Cd administered in offspring by oral route to rats during pregnancy and lactation. There were no adverse effects on the physical and sexual development in the pups, except to delay the development of offspring. The relative weights of livers and kidneys in the adult female offspring were significantly decreased after exposure to 10 ppm Cd. These results indicated that there were adverse effects on growth and development from exposure to 5 or 10 ppm Cd in utero and during lactation. The results also showed differential gender sensitivity effects on the organ weights.

Microbial community compositions in pesticide-contaminated aquifers have not been studied, although such information is important for remediation and maintaining freshwater sources clean under changing climate. Therefore, phospholipid (PLFAs), glycolipid (GLFAs), and neutral lipid (NLFAs) fatty acids were determined from sand and clay sediments at depths of 0.3–24.8 m, all contaminated with triazines and dichlobenil/2,6-dichlorobenzamide. The portion of fungi and Gram-negative bacteria at 0.3 m was greater than at 0.8 m, where the percentage of Gram-positive bacteria, actinobacteria, and sulfate-reducing bacteria (SRB) increased. In deeper sediments, microbial biomass, activity, and diversity decreased. Clay sediments seemed to serve as a reservoir for slow pesticide elution to groundwater, and their biomarker portion for all bacteria except actinobacteria was greater than in sand sediments. The slow pesticide dissipation seemed to occur in the main groundwater flow zone, resulting in nitrogen release simultaneously with organic matter elution from gardening and bank filtration. As a result, microbial biomass, activity, and diversity were increased. This shift in conditions towards that in surface soil may be appropriate for enhanced natural attenuation of pesticides in groundwater sources.

A low crystalline Fe-oxyhydroxy sulfate (FeOS) was used to immobilize arsenic (As) in soils in this study. The effects of FeOS amount, treatment time and soil moisture on As immobilization were investigated. The results showed that water-soluble and NaHCO₃-extractable As were immobilized by 53.4–99.8 and 13.8–73.3 % respectively, with 1–10 % of FeOS addition. The highest immobilization of water-soluble (98.5 %) and NaHCO₃-extractable arsenic (47.2 %) was achieved under condition of 4 % of FeOS and 80 % of soil moisture. Further, more amounts of FeOS addition resulted in less time requirement for As immobilization. Sequential chemical extraction experiment revealed that easily mobile arsenic phase was transferred to less mobile phase. The FeOS-bonded As may play a significant role in arsenic immobilization. Under leaching with simulated acid rain at 60 times pore volumes, accumulation amount of As release from untreated soil and soil amended with FeOS were 98.4 and 1.2 mg, respectively, which correspond to 7.69 and 0.09 % of total As amounts in soil. The result showed that the low crystalline FeOS can be used as a suitable additive for arsenic immobilization in soils.

Di-n-butyl phthalate (DBP), a xenobiotic, is widely used in industries as a softener for polyvinyl chloride resins. The aim of the present study was to evaluate whether DBP induces oxidative stress in testes of Wistar rats. DBP at doses of 500, 1,000 and 1,500 mg/kg b.wt. (doses below LD₅₀) was given orally for 7 days. After 24 hrs from the last dose, the animals were killed under ether anesthesia. Nonsignificant increase in testicular weight was observed. Histological studies indicated a dose-related degeneration of germinal, Leydig and Sertoli cells along with loss of spermatozoa in the lumen. The concentrations of malondialdehyde (TBARS), lipid hydroperoxides, water-soluble antioxidant capacity, glutathione-S-transferase, catalase and trace elements—zinc and copper increased while concentrations of total protein, lipid soluble antioxidant capacity, ascorbic acid, glutathione, total superoxide dismutase (SOD), Cu–ZnSOD, MnSOD, glutathione peroxidase, glutathione reductase and metallothionein decreased at all the dose levels. The data suggests that the cellular functions were adversely affected due to impairment of spermatogenesis indicative of oxidative stress as evident by altered antioxidative defense system which appears to mediate through hypothalamo-pituitary-gonadal axis. The spectrum of changes in testes reflects its susceptibility to phthalate even at low dose with the potential to interfere with critical reproductive function.