Impact of climate change on formation of nitrogenous disinfection by-products. Part II: water blooming and enrichment by humic substances.

Climate change affects the concentration and characteristics of dissolved organic matter (DOM) in surface water. The changes in composition of DOM have many implications to drinking water quality, especially in the case of formation of disinfection by-products (DBPs). The aim of this study was to investigate the formation of nitrogenous DBPs (N-DBPs) during chlorination and chloramination, caused by the alternation of surface water's DOM driven by climate change. For this reason, two different cases were examined: (a) rise of algal organic matter (AOM) due to water blooming and (b) water enrichment by humic substances. The target compounds were haloacetonitriles (HANs), haloacetamides (HAcAms), and halonitromethane (TCNM). The results showed that Anabaena appears to be a major precursor for HAcAms and TCNM, while humic acids are precursors for HANs. The results of the mixtures presented the same pattern. During the water blooming case, HAcAms and TCNM formation are in favor, while during water enrichment by humic substances case, HANs is the N-DBP group with higher formation yield. Cloraminated samples presented higher values of cytotoxicity and genotoxicity compared to the chlorinated.

Marine Microbiota Responses to Shipping Scrubber Effluent Assessed at Community Structure and Function Endpoints.

The use of novel high-throughput sequencing (HTS) technologies to examine the responses of natural multidomain microbial communities to scrubber effluent discharges to the marine environment is still limited. Thus, we applied metabarcoding sequencing targeting the planktonic unicellular eukaryotic and prokaryotic fraction (phytoplankton, bacterioplankton, and protozooplankton) in mesocosm experiments with natural microbial communities from a polluted and an unpolluted site. Furthermore, metagenomic analysis revealed changes in the taxonomic and functional dominance of multidomain marine microbial communities after scrubber effluent additions. The results indicated a clear shift in the microbial communities after such additions, which favored bacterial taxa with known oil and polycyclic aromatic hydrocarbons (PAHs) biodegradation capacities. These bacteria exhibited high connectedness with planktonic unicellular eukaryotes employing variable trophic strategies, suggesting that environmentally relevant bacteria can influence eukaryotic community structure. Furthermore, Clusters of Orthologous Genes associated with pathways of PAHs and monocyclic hydrocarbon degradation increased in numbers at treatments with high scrubber effluent additions acutely. These genes are known to express enzymes acting at various substrates including PAHs. These indications, in combination with the abrupt decrease in the most abundant PAHs in the scrubber effluent below the limit of detection-much faster than their known half-lives-could point toward a bacterioplankton-initiated rapid ultimate biodegradation of the most abundant toxic contaminants of the scrubber effluent. The implementation of HTS could be a valuable tool to develop multilevel biodiversity indicators of the scrubber effluent impacts on the marine environment, which could lead to improved impact assessment. Environ Toxicol Chem 2024;43:1012-1029. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Organophosphate esters in the urban atmosphere of Thessaloniki city, Greece.

The occurrence of organophosphate esters (OPEs) in the atmosphere of the urban area of Thessaloniki city, Greece was studied. OPEs were determined in particulate matter (PM2.5) and precipitation during the period 2020-2021. ∑OPEs in rainwater ranged from 520 to 4719 ng L-11 (mean: 1662 ng L-1) with tris (2-butoxyethyl) phosphate (TBOEP) and tris (1-chloro-2-propyl) phosphate (TClPP) being the most abundant compounds. TBOEP and TClPP as well as triphenylphosphine oxide (TPPO) and tris (chloroethyl) phosphate (TCEP) were the dominant OPEs in PM2.5. Concentrations of ∑OPEs in PM2.5ranged from 2.82 to 13.3 ng m-3 (mean: 5.93 ng m-3). Wet deposition fluxes of OPEs were estimated and air mass back trajectories were used to elucidate possible source profiles. An overall low health risk for local population via inhalation of OPEs was revealed.

Impact of climate change on formation of nitrogenous disinfection by products. Part I: Sea level rise and flooding events.

Climate change causes heavy rainfall incidents and sea level rise, which have serious impact on the availability and quality of water resources. These extreme phenomena lead to the rise of external and internal precursors in water reservoirs, and consequently affect the formation of disinfection by-products (DBPs). The aim of this study was to investigate the formation of nitrogenous_DBPs (N-DBPs) under extreme conditions caused by climate change. For this reason, two scenarios were adapted: a) sea level rise leading to increase of water salinity and b) heavy rainfall incidents leading to flooding events. The target-compounds were haloacetonitriles (HANs), haloacetamides (HAcAms) and halonitromethane (TCNM). Chlorination and chloramination were employed as disinfection processes under different doses (5 and 10 mg/L) and contact times (24 and 72 h). The results showed enhancement on the formation of N-DBPs and changes in their profile. Sea level rise scenario led to elevated concentrations of brominated species (maximum concentration of dibromoacetonitrile 23 µg/L and maximum concentration of bromoacetamide 57 µg/L), while flooding events scenario led to extended formation of chloroacetamide and bromochloroacetonitrile up to 58 µg/L and 40 µg/L, respectively. At the same time, changes in cytotoxicity and genotoxicity of the samples were observed.

Hazardous organic pollutants in indoor dust from elementary schools and kindergartens in Greece: Implications for children's health.

Children spend a significant portion of their day in school, where they may be exposed to hazardous organic compounds accumulated in indoor dust. The aim of this study was to evaluate the concentrations of major hazardous organic contaminants in dust collected from kindergartens and elementary schools in Northern Greece (n = 20). The sum concentrations of 20 targeted polybrominated diphenyl ether congeners (∑20PBDEs) in dust varied from 58 ng g-1 to 1480 ng g-1, while the sum of 4 novel brominated fire retardants (∑4NBFRs) ranged from 28 ng g-1 to 555 ng g-1. Correspondingly, the sum concentrations of phthalate esters (∑9PAEs) ranged between 265 µg g-1 and 2120 µg g-1, while the sum of organophosphate esters (∑11OPEs) was found between 2890 ng g-1 and 16,100 ng g-1. Finally, the sum concentrations of polycyclic aromatic hydrocarbons (∑16PAHs) were found within in the range 212 ng g-1 and 6960 ng g-1. Exposure to indoor dust contaminant via inhalation, ingestion and dermal absorption was investigated for children and adults (teachers). Carcinogenic and non-carcinogenic risks were also estimated. Children's estimated intakes of individual hazardous chemicals via the three exposure routes, were lower than the available health-based reference values.

A catastrophic change in a european protected wetland: From harmful phytoplankton blooms to fish and bird kill.

Understanding the processes that underlay an ecological disaster represents a major scientific challenge. Here, we investigated phytoplankton and zooplankton community changes before and during a fauna mass kill in a European protected wetland. Evidence on gradual development and collapse of harmful phytoplankton blooms, allowed us to delineate the biotic and abiotic interactions that led to this ecological disaster. Before the mass fauna kill, mixed blooms of known harmful cyanobacteria and the killer alga Prymnesium parvum altered biomass flow and minimized zooplankton resource use efficiency. These blooms collapsed under high nutrient concentrations and inhibitory ammonia levels, with low phytoplankton biomass leading to a dramatic drop in photosynthetic oxygenation and a shift to a heterotrophic ecosystem phase. Along with the phytoplankton collapse, extremely high numbers of red planktonic crustaceans-Daphnia magna, visible through satellite images, indicated low oxygen conditions as well as a decrease or absence of fish predation pressure. Our findings provide clear evidence that the mass episode of fish and birds kill resulted through severe changes in phytoplankton and zooplankton dynamics, and the alternation on key abiotic conditions. Our study highlights that plankton-related ecosystem functions mirror the accumulated heavy anthropogenic impacts on freshwaters and could reflect a failure in conservation and restoration measures.

Occurrence and removal of organophosphate esters in municipal wastewater treatment plants in Thessaloniki, Greece.

An integrate study regarding the occurrence and fate of eleven organophosphate esters (OPEs) was conducted at two wastewater treatment plants (WWTPs) in the area of Thessaloniki, Greece. Both plants employed conventional activated sludge process whereas as last treatment step the first unit use chlorination and the second one ozonation. OPEs were determined in dissolved fraction, total suspended solids and sludge from various treatment stages of WWTPs. Tris (2-butoxyethyl) phosphate (TBOEP), tris (1-chloro-2-propyl) phosphate (TClPP) and triphenylphosphine oxide (TPPO) were the most abundant compounds in influent and treated effluent. Triphenyl phosphate (TPHP) was also abundant in suspended solids and sludge. Total concentrations of ∑11OPEs ranged from 2144 to 9743 ng L-1 in influents, 1237-2909 ng L-1 in effluents and 3332-14294 ng g-1 dw in sludge. Removal rates from 55% to 80% were observed for most OPEs, whereas chlorinated OPEs, especially for tris(2-chloroethyl) phosphate (TCEP) exhibited low removal efficiency. Mass balance analysis showed that biodegradation was the dominant removal mechanism contributing up to 85%. Sorption onto sludge was also relevant removal pathway for most compounds. Emissions of OPEs through effluents and sludge did not pose considerable risk to the aquatic and terrestrial environment.

Occurrence of Disinfection By-Products in Swimming Pools in the Area of Thessaloniki, Northern Greece. Assessment of Multi-Pathway Exposure and Risk.

This study investigated the occurrence of disinfection by-products (DBPs) (trihalomethanes (THMs), haloacetic acids (HAAs), halonitriles (HANs), halonitromethane (TCNM) and haloketones (HKs)) in different type of swimming pools in the area of Thessaloniki, northern Greece by employing the EPA methods 551.1 and 552.3. Moreover, general water quality parameters (pH, residual chlorine, dissolved organic carbon, UV254 absorption, total nitrogen, alkalinity and conductivity) were also measured. The concentrations of DBPs showed great variability among swimming pools as well as within the same pool between sampling campaigns. HAAs exhibited the highest concentrations followed by THMs, HANs, TCNM and HKs. Exposure doses for four age groups (3-<6 y, 6-<11 y, 11-<16 y and adults) were calculated. Route-specific exposures varied among DBPs groups. Inhalation was the dominant exposure route to THMs and TCNM (up to 92-95%). Ingestion and dermal absorption were the main exposure routes to HAAs (40-82% and 18-59%, respectively), depending on the age of swimmers. HANs contributed up to 75% to the calculated cytotoxicity of pool water. Hazard indices for different exposure routes were <1, suggesting non-carcinogenic risk. Inhalation posed the higher carcinogenic risk for THMs, whereas risk via oral and dermal routes was low. Ingestion and dermal contact posed the higher risk for HAAs. Risk management strategies that minimise DBPs exposure without compromising disinfection efficiency in swimming pools are necessary.

Organophosphate esters in inland and coastal waters in northern Greece.

The occurrence and distribution of organophosphate esters (OPEs) in inland and coastal waters in Thessaloniki, Greece, were studied during the period 2019-2020. Samples from rivers and streams as well as coastal waters, were analyzed for the presence of 11 OPEs in dissolved and particulate fraction. OPEs were ubiquitous pollutants in the aquatic environment. Concentrations of dissolved fraction of ΣOPEs concentrations ranged from 400 to 2158 ng L-1 in rivers, 400-1270 in coastal sites and 377-30,560 ng L-1 in streams. TBOEP showed the highest concentrations followed by TPHP, TNBP and TClPP. Significant particulate fractions were determined for TNBP, TClPP TPHP and TCP. Field partition coefficients in inland waters were dependent on the concentration of total suspended solids. Risk assessment did not show potential threat due to OPEs in rivers and coastal sites, however, potential adverse effects were found in streams.

Toxic organic pollutants in Greek house dust: Implications for human exposure and health risk.

Organic contaminants often documented in house dust include mainly chemicals released from construction materials and consumer products and compounds emitted from indoor combustion activities. The occurrence of major chemical classes of toxic organic pollutants, included polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (NPAHs), was for the first time investigated in house dust in Greece. The mean concentrations of ∑16PAHs, ∑20PBDEs, ∑7NPAHs and∑15PCBs in house dust were 4650 ng g-1, 564 ng g-1, 7.52 ng g-1, and 6.29 ng g-1, respectively. Exposure to dust organic contaminants via ingestion, inhalation and dermal absorption was estimated for two age classes (adults and children) and carcinogenic and non-carcinogenic risks were assessed. The hazard index (HI) for adults and children for PBDEs, PCBs, PAHs and NPAHs in all samples was less than 1 suggesting a very low level of concern for all human age group due to exposure to those chemicals. Total carcinogenic risk via the three exposure pathways (ingestion, inhalation and dermal contact) was within the safe range of 10-6 to 10-4.

Occurrence, analysis and risk assessment of organophosphate esters (OPEs) in biota: A review.

Due to their widespread use, organophosphate esters (OPEs) are commonly detected in various environmental matrices and have been identified as emerging contaminants. In this review article, the occurrence and analytical techniques of OPEs in the biotic environment have been compiled and reviewed. Data from studies published the last decade all over the world covering a variety of species in trophic chain have been synthesized and evaluated. OPEs are among the most frequent detected flame retardants and high concentrations are detected in biota to date. Knowledge gaps and recommendations for future research are discussed emphasizing on further monitoring, advanced analytical methodologies, and risk assessment studies to completely understand the science of OPEs in biota.

Organophosphate flame retardants (OPFRs): A review on analytical methods and occurrence in wastewater and aquatic environment.

Nowadays, there is an increasing concern for organophosphate flame retardants (OPFRs) due to high production and use following the phase out and stringent regulation in the use of brominated flame retardants. OPFRs represent a group of compounds with a wide range in their polarity, solubility and persistence. OPFRs are widely used as flame retardants in various consumer products such as textiles, electronics, industrial materials and furniture to prevent the risk of fire. They are also utilized as plasticizers, antifoaming or anti-wear agents in lacquers, hydraulic fluids and floor polishing agents. The present review outlines the current state of knowledge regardimg the analytical methodology applied for their determination in wastewater and aquatic environment as well as their occurrence in water, wastewater, sediments and sludge. Knowledge gaps and future perspectives have been identified, which include the elucidation of sources, pathways and fate of OPFRs in aquatic environment and possible risks.

Removal of bisphenol A by Fe-impregnated activated carbons.

A commercial wood-based activated carbon and the oxidized counterpart were impregnated with iron. The two Fe-impregnated carbons were prepared and characterized for their iron content, textural characteristics, surface chemistry, and their performance for bisphenol A adsorption. Batch adsorption experiments were conducted to study the effect of pH, ionic strength, kinetics, and thermodynamic equilibrium. Equilibrium adsorption data were described by both Langmuir and Freundlich isotherms. The iron impregnated activated carbon and the oxidized impregnated activated carbon presented maximum adsorption capacities of 785.65 and 469.78 mg/g, respectively, while adsorption followed second-order rate kinetics for both impregnated carbons. According to the thermodynamic parameters (ΔΗο, ΔSo, ΔGo), the adsorption is a spontaneous, exothermic, and physical process. Fenton-driven experiments conducted at different molar ratios of [H2O2]/[BPA] showed efficient degradation of BPA in spent Fe-impregnated carbons up to 82-95%, with traces of hydroxylated products.

Formation of iodinated THMs during chlorination of water and wastewater in the presence of different iodine sources.

The formation potential of iodinated trihalomethanes (I-THMs) during chlorination of different organic precursors in the presence of various iodine sources was studied. Organic precursors included humic acid, natural organic matter from river water and wastewater effluent organic matter. Inorganic iodide and two iodinated X-ray contrast media compounds (iopamidol and diatrizoate) were used as iodine sources. The formation potential of I-THMs under different experimental conditions (chlorination contact time, iodide and bromide concentrations) was investigated. The formation of I-THM species upon chlorination of river water and humic acids rapidly increased up to 24h and then a decreasing trend was observed. Wastewater, showed a rapid formation of I-THMs within the first 6h, followed by a lower rate with extended time. Formation of I-THMs in the presence of iopamidol was more favorable regarding the other two iodine sources. CHBrClI was the dominant specie followed by CHCl2I and CHBr2I. Increasing iodide concentrations result in higher I-THMs formation. The presence of bromide enhanced the I-THMs yields and shifted towards bromine-containing species (CHBrClI and CHBr2I).

Study of polar organic compounds in airborne particulate matter of a coastal urban city.

Two classes of polar organic compounds, dicarboxylic acids (DCAs) and sugars/sugar anhydrides (S/SAs), were measured in airborne particulate matter in the area of Thessaloniki, northern Greece. The target compounds were measured simultaneously in two particle fractions PM10 and PM2.5 during cold and warm periods by employing extraction in an ultrasonic bath with a mixture of MeOH/DCM (1:2 v/v), derivatization with BSTFA-TMCS and GC-MS for analysis. At both fractions, phthalic was the predominant carboxylic acid during cold season and a-ketoglutaric acid in warm season, followed by maleic and malic. Levoglucosan was the dominant sugar anhydride during the cold and arabitol during the warm season. In total, the distribution of DCAs seemed to favor the PM2.5 particle fraction, probably due to anthropogenic emissions and photochemical formation. The relative contribution of DCAs to PM2.5 fraction was 0.9-3.2% in cold and 0.9-7.0% in warm period. Regarding S/SAs, levoglucosan was also predominantly distributed in fine particles, with relative contribution to this fraction 0.1-6.3% in cold and <0.65% in warm season, suggesting impact of biomass burning emissions. In contrast, arabitol, fructose, and glucose were mainly found in coarse fraction, possibly due to their biogenic origin. Negative correlation of target compounds with temperature and total solar radiation suggested the contribution of seasonal dependant local sources. Positive relationship with NO and NO2 oxidants and relative humidity showed secondary formation of polar compounds or enhanced gas-to-particle conversion.

Polybrominated diphenyl ethers (PBDEs) in background air around the Aegean: implications for phase partitioning and size distribution.

The occurrence and atmospheric behavior of tri- to deca-polybrominated diphenyl ethers (PBDEs) were investigated during a 2-week campaign concurrently conducted in July 2012 at four background sites around the Aegean Sea. The study focused on the gas/particle (G/P) partitioning at three sites (Ag. Paraskevi/central Greece/suburban, Finokalia/southern Greece/remote coastal, and Urla/Turkey/rural coastal) and on the size distribution at two sites (Neochorouda/northern Greece/rural inland and Finokalia/southern Greece/remote coastal). The lowest mean total (G + P) concentrations of ∑7PBDE (BDE-28, BDE-47, BDE-66, BDE-99, BDE-100, BDE-153, BDE-154) and BDE-209 (0.81 and 0.95 pg m-3, respectively) were found at the remote site Finokalia. Partitioning coefficients, K P, were calculated, and their linear relationships with ambient temperature and the physicochemical properties of the analyzed PBDE congeners, i.e., the subcooled liquid pressure (P L°) and the octanol-air partition coefficient (K OA), were investigated. The equilibrium adsorption (P L°-based) and absorption (K OA-based) models, as well as a steady-state absorption model including an equilibrium and a non-equilibrium term, both being functions of log K OA, were used to predict the fraction Φ of PBDEs associated with the particle phase. The steady-state model proved to be superior to predict G/P partitioning of BDE-209. The distribution of particle-bound PBDEs across size fractions < 0.95, 0.95-1.5, 1.5-3.0, 3.0-7.2, and > 7.2 µm indicated a positive correlation between the mass median aerodynamic diameter and log P L° for the less brominated congeners, whereas a negative correlation was observed for the high brominated congeners. The potential source regions of PBDEs were acknowledged as a combination of long-range transport with short-distance sources.

Toxic organic substances and marker compounds in size-segregated urban particulate matter - Implications for involvement in the in vitro bioactivity of the extractable organic matter.

Toxic organic substances and polar organic marker compounds, i.e. polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and their nitro-derivatives (N-PAHs), as well as dicarboxylic acids (DCAs) and sugars/sugar anhydrites (S/SAs) were analyzed in size-segregated PM samples (<0.49, 0.49-0.97, 0.97-3 and >3 µm) collected at two urban sites (urban traffic and urban background) during the cold and the warm season. The potential associations between the organic PM determinants and the adverse cellular effects (i.e. cytotoxicity, genotoxicity, DNA damage, oxidative DNA adduct formation, and inflammatory response) induced by the extractable organic matter (EOM) of PM, previously measured in Velali et al. (2016b), were investigated by bivariate correlations and Principal Component Analysis (PCA). Partial Least Square regression analysis (PLS) was also employed in order to identify the chemical classes mainly involved in the EOM-induced toxicological endpoints in the various particle size fractions. Results indicated that particle size range <0.49 µm was the major carrier of PM mass and organic compounds at both sites. All toxic organic compounds exhibited higher concentrations at the urban traffic site, except PCBs and OCPs that did not exhibit intra-urban variations. Conversely, wintertime levels of levoglucosan were significantly higher at the urban background site as a result of residential biomass burning. The PLS regression analysis allowed quite good prediction of the EOM-induced cytotoxicity and genotoxicity based on the determined organic chemical classes, particularly for the finest size fraction of PM. Nevertheless, it is expected that other chemical constituents, not determined here, also contribute to the measured toxicological responses.

Study of persistent toxic pollutants in a river basin-ecotoxicological risk assessment.

This study presents a complementary approach for the evaluation of water quality in a river basin by employing active and passive sampling. Persistent toxic pollutants representing three classes: organochlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), were studied in grab water samples, in passive samplers/SemiPermeable Membrane Devices (SPMDs) and in fish tissues collected along the Strymonas River, northern Greece at three sampling campaigns during the year 2013. Almost all the target compounds were detected in the study river of Strymonas, northern Greece at the periods of high rainfall intensity and/or low flow-rate. The most frequently detected compounds were 1,2-benzanthracene, benzo(a)pyrene, benzo(b)fluoranthene, endosulfan I, endosulfan II, endosulfan sulfate, endrin aldehyde, fluorene, methoxychlor, polychlorinated biphenyl PCB 28, PCB 180 and pyrene. The family of DDT compounds and aldrin were also occasionally detected. Agricultural run-off and waste effluents are the main sources of hydrophobic organic compounds in the river basin. The use of SPMDs allowed the detection of more micropollutants than active sampling (31 vs. 16, respectively). Results showed relatively low risk however the potential risk associated with micropollutants such as 1,2-benzanthracene, benzo(b)fluoranthene, p,p-dichlorodiphenyldichloroethane (DDD), endosulfan II, methoxychlor, PCB 180 and pyrene should not be neglected. Performing risk assessment based on passive sampling, more information was obtained about temporal and spatial variation. SPMDs could be applied as a pre-evaluation before chemical monitoring in biota.