The Mediterranean area is highly vulnerable to climate changes that combined with potential land use changes could influence its aquatic systems significantly. The Evros River is one of the most important surface water bodies in the Balkans with an ecologically significant delta that is protected by international legislation. The aim of this study is to analyze the impacts of climate and land use changes on Evros River water quality, for different climatic and socioeconomic scenarios. For this purpose, a hydrodynamic and advection-dispersion model was set up and calibrated, three IPCC climatic scenarios were applied, and the pollution loads of the catchment area were estimated. These scenarios involved river discharge decrease due to regional climate changes and socioeconomic and technological development that would lead to population growth and to the decrease of agricultural activities. The results indicated that in the case of discharge reduction only, the total nitrate and phosphate concentrations will be increased, while in case of combined land use and discharge changes, the concentration of nutrients will be decreased. Thus, a transboundary long-term management plan of the entire River is needed that would eliminate the pollution pressures and restore its good ecological status.

Anthropic eutrophication is one of the most widespread problems affecting water quality worldwide. This condition is caused by excessive nutrient inputs to aquatic systems, and one of the main consequences is accelerated phytoplankton growth. Eutrophication can lead to damage to human health, the environment, society, and the economy. One of the most serious consequences of eutrophication is the proliferation of cyanobacteria that can release toxins into the water. The aim of this research was to evaluate the trophic condition of a tropical reservoir over the course of time, using a database extending over 15 years to investigate relationships with environmental conditions, considering spatial heterogeneity and seasonality, as well as inter-relations between trophic state indicators. Data for chlorophyll-a, total phosphorus, and total nitrogen were collected from 2000 to 2014, and cyanobacteria abundance was determined from 2004 to 2014. The trophic state index was also calculated. The results demonstrated the existence of two distinct compartments in the reservoir: one lotic and the other lentic. No relationship was observed between chlorophyll-a and phosphorus. The results suggested that phytoplankton growth was mainly controlled by nitrogen concentrations. These conditions favored cyanobacteria predominance, resulting in increasing abundance of these potentially toxic bacteria over time. The model obtained indicated hypereutrophic conditions, with high phytoplankton biomass and cyanobacteria abundance during the next years likely to affect the uses of the water of the reservoir.

For the purpose of clarifying the chemical nature of fly ashes, the raw fly ashes were collected from the stacks of 17 fixed sources consisting of 15 municipal waste incinerators, a metal melting factory, and a cement plant all of which are located in the western Japan from Nov. 2000 to Jan. 2007. The municipal waste incinerators were successfully classified into four groups in terms of the relative mass ratios between chloride, potassium, and sodium. Sodium, potassium, and calcium were found abundantly in fly ashes collected from all four types of municipal waste incinerators. The theoretical estimation of chlorine form suggested that the form of NaCI, KCl, MgCl, and CaCl₂ accounted for approximately 55 % of total chlorine in raw fly ash. Trace heavy metals (i.e., Zn, Mn, Pb, Cu, Cr, Ni, and V) were preferentially enriched in the ambient PM₂.₅ which was strongly influenced by regional stationary sources (including municipal waste incinerators). The water-soluble OC to TC fraction in the fly ashes of municipal waste incinerator, metal furnace, and cement plant was estimated as 56.8, 79.0, and 89.6 %, respectively.

Although 8-hydroxy-2-deoxyguanosine (8-OHdG) is a widely used promising biomarker of DNA damage, there are concerns about which tissues or body fluids should be sampled. The objective of this study is to evaluate the correlation of DNA oxidative damage biomarkers, 8-OHdG, between blood and urine and risk factors associated with 8OHdG. The study population was recruited from a baseline survey of a worksite lifestyle study including 92 office workers aged 23 to 60 years. A self-administered questionnaire was used to collect information on personal characteristics. The plasma and urinary 8-OHdG was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). In linear regression, a positive relation was found (p < 0.01) between the log-transformed plasma and urinary 8-OHdG levels adjusted for gender, age, BMI, and smoking status. Our findings showed that age, gender and smoking were significantly associated with plasma 8-OHdG, but not with urinary 8-OHdG. Our results suggest that there is a positive relation between the biomarkers of plasma (steady state DNA damage) and urinary 8-OHdG (total DNA damage). However, the plasma 8-OHdG is more sensitive than urinary 8-OHdG to detect increased oxidative damages induced by risk factors.

We conducted multiday continuous monitoring of indoor and outdoor particulate matter (PM) in classrooms with fan-assisted natural ventilation (NV) at five primary schools in Singapore. We monitored size-resolved number concentration of PM with diameter 0.3–10 μm at all schools and alveolar deposited surface area concentrations of PM with diameter 0.01–1.0 μm (SA₀.₀₁–₁.₀) at two schools. Results show that, during the monitoring period, schools closer to expressways and in the downtown area had 2–3 times higher outdoor PM₀.₃–₁.₀ number concentrations than schools located in suburban areas. Average indoor SA₀.₀₁–₁.₀ was 115–118 μm² cm⁻³ during periods of occupancy and 72–87 μm² cm⁻³ during unoccupied periods. There were close indoor and outdoor correlations for fine PM during both occupied and unoccupied periods (Pearson’s r = 0.84–1.0) while the correlations for coarse PM were weak during the occupied periods (r = 0.13–0.74). Across all the schools, the size-resolved indoor/outdoor PM ratios (I/O ratios) were 0.81 to 1.58 and 0.61 to 0.95 during occupied and unoccupied periods, respectively, and average infiltration factors were 0.64 to 0.94. Average PM net emission rates, calculated during periods of occupancy in the classrooms, were lower than or in the lower range of emission rates reported in the literature. This study also reveals that indoor fine and submicron PM predominantly come from outdoor sources, while indoor sources associated with occupancy may be important for coarse PM even when the classrooms have high air exchange rates.

Nutrition and pollution stress stimulate genetic adaptation in microorganisms and assist in evolution of diverse metabolic pathways for their survival on several complex organic compounds. Persistent organic pollutants (POPs) are highly lipophilic in nature and cause adverse effects to the environment and human health by biomagnification through the food chain. Diverse microorganisms, harboring numerous plasmids and catabolic genes, acclimatize to these environmentally unfavorable conditions by gene duplication, mutational drift, hypermutation, and recombination. Genetic aspects of some major POP catabolic genes such as biphenyl dioxygenase (bph), DDT 2,3-dioxygenase, and angular dioxygenase assist in degradation of biphenyl, organochlorine pesticides, and dioxins/furans, respectively. Microbial metagenome constitutes the largest genetic reservoir with miscellaneous enzymatic activities implicated in degradation. To tap the metabolic potential of microorganisms, recent techniques like sequence and function-based screening and substrate-induced gene expression are proficient in tracing out novel catabolic genes from the entire metagenome for utilization in enhanced biodegradation. The major endeavor of today’s scientific world is to characterize the exact genetic mechanisms of microbes for bioremediation of these toxic compounds by excavating into the uncultured plethora. This review entails the effect of POPs on the environment and involvement of microbial catabolic genes for their removal with the advanced techniques of bioremediation.

Since it was commercially introduced in 1974, glyphosate has been one of the most commonly used herbicides in agriculture worldwide, and there is growing concern about its adverse effects on the environment. Assuming that glyphosate may increase the organic turbidity of water bodies, we evaluated the effect of a single application of 2.4 ± 0.1 mg l⁻¹ of glyphosate (technical grade) on freshwater bacterioplankton and phytoplankton (pico, micro, and nanophytoplankton) and on the physical and chemical properties of the water. We used outdoor experimental mesocosms under clear and oligotrophic (phytoplanktonic chlorophyll a = 2.04 μg l⁻¹; turbidity = 2.0 NTU) and organic turbid and eutrophic (phytoplanktonic chlorophyll a = 50.3 μg l⁻¹; turbidity = 16.0 NTU) scenarios. Samplings were conducted at the beginning of the experiment and at 1, 8, 19, and 33 days after glyphosate addition. For both typologies, the herbicide affected the abiotic water properties (with a marked increase in total phosphorus), but it did not affect the structure of micro and nanophytoplankton. In clear waters, glyphosate treatment induced a trend toward higher bacteria and picoeukaryotes abundances, while there was a 2 to 2.5-fold increase in picocyanobacteria number. In turbid waters, without picoeukaryotes at the beginning of the experiment, glyphosate decreased bacteria abundance but increased the number of picocyanobacteria, suggesting a direct favorable effect. Moreover, our results show that the impact of the herbicide was observed in microorganisms from both oligo and eutrophic conditions, indicating that the impact would be independent of the trophic status of the water body.

This study evaluates the present day effects of air pollutants emitted from an iron sintering plant near Wawa (Ontario, Canada) decades ago (1939–1998). During smelting and refining of iron ore, gaseous sulfur-rich emissions and large amounts of metal-containing (iron oxides) particulate materials were released in to the air, and eventually settled onto vegetation and soil cover. We test the feasibility of using magnetic measurements to investigate and quantify the soil pollution resulting from the sintering plant. Surface and subsurface magnetic susceptibility measurements, as well as various magnetic mineral properties, have been collected in a scheme designed to mimic the previously determined pollutant contamination zones. A total of 50 sites were sampled (with a sampling grid of 250 m) within and around the smelter kill zone to the northwest of Wawa. Results were plotted on cross sections perpendicular (X-X′) and parallel (Y-Y′) to the dominant wind direction in order to investigate magnetic properties of the soil samples as a function of both wind direction and distance from the source. Samples located in Rao and LeBlanc’s (The Bryologist 70:141–17, 1967) pollution zones 1 and 2 typically have κ ᵢₙ₋ₛᵢₜᵤ values >120 × 10⁻⁵ SI, while the zone 3 and 4 results are <100 × 10⁻⁵ SI. Magnetic susceptibility enhancements at depths of 5–10 cm were found to be related to the presence of magnetic spherules (fly-ashes) at sites on the wind-parallel Y-Y′ profile in the previously defined kill zone. An estimated minimum migration rate of iron-rich particulates is calculated for coarse sand and silt/clay sites as 0.24 and 0.1 cm/year, respectively.

Three macrophyte species, Typha augustifolia (T. augustifolia), Phragmites australis (P. australis), and Acorus calamus L. (A. calamus L.), have been grown in hydroponic cultivation systems fed with synthetic wastewater. The experiment was designed as 3 × 2 factorial, with three species and two ratios of NH₄ ⁺/NO₃ ⁻ so as to investigate the nitrogen transformation and nitrogen removal capacity of each species. The nitrogen removal mechanism was further disclosed by comparing biomass production, nitrogen mass balance, and root exudates of the three plant species under different NH₄ ⁺/NO₃ ⁻ ratios. The results indicated there exists a linear relationship, with positive significance (r = 0.946, p < 0.05), between plant biomass and total nitrogen (TN) removal efficiency; in other words, biomass could best reflect plant ability to remove nitrogen. It is also found that NH₄ ⁺/NO₃ ⁻ ratio could influence plant biomass and root exudates significantly. Additionally, the hydrogen donor and source of energy in denitrification happened in this research were mainly organic acids and soluble sugars, accounting for approximately 50 % of the composition in root exudates.

The fate of emerging organic micropollutants (EOMs) in wastewater treatment plants (WWTPs) is still not fully determined, and further studies are still needed to assess whether the existing treatment units can be further exploited (e.g., by modifying the operating parameters) or new and different techniques have to be implemented for their removal. The present study investigates the fate of a class of EOMs, i.e., the endocrine disrupting chemicals (EDCs), in batch-activated sludge tests under mixed and aerated conditions, as those usually adopted in full-scale WWTPs. Among the EDCs, the research focused on: bisphenol A, 17α-ethinylestradiol (EE2), and two natural EDCs—estrone (E1) and 17β-estradiol (E2). By applying different operating conditions to the tests, it was possible to distinguish between contributions due to volatilization, adsorption onto the sludge flocs, and biodegradation to the overall removal of each EDC. It was found that all the investigated EDCs were removed mainly by adsorption and biodegradation. Starting from a relatively high concentration (1000 ng/L), the removal process was capable of reducing the influent load to very low values within the duration of the test (i.e., 48 h). Kinetics of the removal process were found to be best fitted by the pseudo-second-order model for all the investigated EDCs; the values of the relative constants were always found to be equal to about 0.0023 1/h. Furthermore, the values of the coefficients K D and K OM were determined and found to be comparable with the data reported by the specialized literature.