RESUMEN

The ultraviolet (UV) component of sunlight can damage DNA. Although most solar UV is absorbed by the ozone layer, wavelengths > 300 nm (UVA and UVB bands) can reach the Earth's surface. It is essential to understand the genotoxic effects of UV light, particularly in natural environments. Caulobacter crescentus, a bacterium widely employed as a model for cell cycle studies, was selected for this study. Strains proficient and deficient in DNA repair (uvrA-) were used to concurrently investigate three genotoxic endpoints: cytotoxicity, SOS induction, and gene mutation, using colony-formation, the SOS chromotest, and RifR mutagenesis, respectively. Our findings underscore the distinct impacts of individual UV bands and the full spectrum of sunlight itself in C. crescentus. UVC light was highly genotoxic, especially for the repair-deficient strain. A UVB dose equivalent to 20 min sunlight exposure also affected the cells. UVA exposure caused a significant response only at high doses, likely due to activation of photorepair. Exposure to solar irradiation resulted in reduced levels of SOS induction, possibly due to decreased cell survival. However, mutagenicity is increased, particularly in uvrA- deficient cells.

Asunto(s)

RESUMEN

Pteris vittata L. is a terrestrial genus growing in moist, shady forests and on hillsides. The plant has considerable ethnomedicinal importance. Investigations have been carried out on chemical profiling and antioxidant compounds from some genera of pteridophytes but studies on the biological properties of P. vittata are lacking. Therefore, the present study investigates antioxidant, antigenotoxic, and antiproliferative potential of the aqueous fraction of P. vittata (PWE). A battery of assays were carried out to assess the antioxidant potential of the PWE. SOS chromotest and DNA nicking assay were used to evaluate the antigenotoxicity of the fraction. The cytotoxic effect of PWE was analyzed using MTT and Neutral Single Cell Gel Electrophoresis comet assay. EC50 of 90.188 µg/ml, 80.13 µg/ml, 142.836 µg/ml, and 12.274 µg/ml was obtained in DPPH, superoxide anion scavenging, reducing power and lipid peroxidation assays, respectively. PWE was potent in inhibiting Fenton's reagent-induced nicking of pBR322 plasmid. The fraction significantly inhibited hydrogen peroxide (H2O2) and 4-nitroquinoline-N-oxide (4NQO) induced mutagenicity and a reduction in induction factor was found with increased PWE concentration. GI50 of 147.16 µg/ml was obtained in MTT assay in human MCF-7 breast cancer cell line. PWE induced apoptosis as confirmed from confocal microscopy studies. The protective effects can be attributed to the presence of the phytochemicals in PWE. These results will be helpful in the development of functional food characteristics, as well as unravel the benefits of pteridophytes as promoters of health.

Asunto(s)

RESUMEN

Since DNA damage can occur spontaneously or be produced by the environmental genotoxins in living cells, it is important to investigate compounds that can reverse or protect DNA damage. An appropriate methodology is essential for the responsive identification of protection offered against DNA damage. This review includes information on the current state of knowledge on prokaryotic cell-based assays (SOS chromotest, umu test, vitotox assay) and cytogenetic techniques (micronucleus assay, chromosome aberration test and sister chromatid exchange assay) with an emphasis on the possibility to explore genoprotective compounds. Throughout the last decade, studies have extrapolated the scientific methodologies utilized for genotoxicity to assess genoprotective compounds. Therefore, shortcomings of genotoxicity studies are also mirrored in antigenotoxicity studies. While regulatory authorities around the world (OECD, US-EPA and ICH) continue to update diverse genotoxic assay strategies, there are still no clear guidelines/approaches for efficient experimental design to screen genoprotective compounds. As a consequence, non-synergetic and inconsistent implementation of the test method by the researchers to execute such simulations has been adopted, which inevitably results in unreliable findings. The review has made the first attempt to collect various facets of experimentally verified approaches for evaluating genoprotective compounds, as well as to acknowledge potential significance and constraints, and further focus on the assessment of end points which are required to validate such action. Henceforth, the review makes an incredible commitment by permitting readers to equate several components of their test arrangement with the provided simplified information, allowing the selection of convenient technique for the predefined compound from a central repository.

Asunto(s)

RESUMEN

The chemical components of plastic wastes have made their disposal a major economic, social, and environmental problem worldwide. This study evaluated the acute toxicity and genotoxicity of marine plastic debris on the beaches of Concepción Bay, Central Chile, taken during three periods (spring, summer, and winter). An integrated approach was used, including chemical and toxicological data, using the Microtox® test with Vibrio fischeri and SOS chromotest with Escherichia coli and concentrations of polychlorinated biphenyls (PCBs), Organochlorine Pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The results presented here exclusively include the novel data obtained from the winter campaign, revealing high concentrations of PBDEs (238 ± 521 ng g-1). In addition, the genotoxicity and acute toxicity tests were sensitive for most of the samples studied. This investigation is the first attempt to analyse the toxicity of plastic debris in coastal areas along the Chilean coast.

Asunto(s)

RESUMEN

Concern on the toxicity of final wastewater generated by the petroleum refining industry has increased in recent years due to the potential health threats associated with their release into the waterways. This study determined the mutagenic and genotoxic potential of petroleum refinery wastewater and a receiving river using the Ames fluctuation test on Salmonella typhimurium strains TA100 and TA98, SOS chromotest on Escherichia coli PQ37, and piscine peripheral micronucleus (MN) assay. Analyses of the physicochemical parameters, heavy metal, and organic contents of the samples were also performed. Ames test result showed that the two tested samples were mutagenic with TA100 strain as the more responsive strain for both the refinery wastewater and the river sample in terms of the calculated mutagenic index. A similar result was obtained in the SOS chromotest; however, the E. coli PQ37 system recorded a slightly higher sensitivity for detecting genotoxins than the Salmonella assay in the two samples. MN data showed induction of a concentration-dependent significant (p < 0.05) increase in the frequency of MN by both samples when compared with the negative control. Generally, the refinery wastewater induced the highest mutagenicity and genotoxicity compared to the river sample in the three assays used. Haemoglobin, platelets, red blood cells, mean corpuscular volume, total white blood cells, heterophils, haematocrit, and eosinophils reduced significantly with increased lymphocytes, basophils, mean corpuscular haemoglobin, and mean corpuscular haemoglobin concentration in fishes exposed to both samples. Total petroleum hydrocarbon, benzene, toluene, phenol index, polycyclic aromatic hydrocarbons, cadmium, mercury, nickel, lead, and vanadium contents analysed in the samples were believed to be responsible for the observed genotoxicity and mutagenicity. The findings of this study revealed that petroleum refinery wastewater is a potential mutagenic and genotoxic risk to the environment.

Asunto(s)

RESUMEN

Mine water as a result of meteoric and/or underground water's contact with tailings and underground workings could have an elevated content of metals associated with sulfate, often acidic, due to the bio-oxidation of sulfides. When entering aquatic ecosystems, the mine water can cause significant changes in the species' trophic levels, therefore a treatment is required to adjust the alkalinity and to remove the heavy metals and metalloids. The conventional mine water treatment removes metals, but in many cases it does not reduce the sulfate content. This paper aimed to predict the impact of conventionally treated mine water on the receiving river by assessing the genotoxic activity on an engineered Escherichia coli and by evaluating the toxic effects generated on two Gram-negative bacterial strains, Pseudomonas aeruginosa and Escherichia coli. Although the main chemical impact is the severe increases of calcium and sulfate concentrations, no significant genotoxic characteristics were detected on the Escherichia coli strain and on the cell-viability with a positive survival rate higher than 80%. Pseudomonas aeruginosa was more resistant than Escherichia coli in the presence of 1890 mg SO42-/L. This paper reveals different sensitivities and adaptabilities of pathogenic bacteria to high concentrations of sulfates in mine waters.

Asunto(s)

RESUMEN

The practice of burning household waste including different types of plastic is illegal in Hungary, still an existing problem. As environmental consequences are hardly known, this study attempts to give an initial estimation of the ecotoxicity generated during controlled combustion of different waste types. These samples included polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PU), oriented strand board (OSB) and rag (RAG). Ecotoxicological profiling was completed using the following test battery: Vibrio fischeri bioluminescence inhibition assay, Daphnia magna immobility test and the seedling emergence assay. Also, genotoxicity of plastic waste samples was assessed using the SOS Chromotest. Concerning main pollutants in the samples, the samples could be distinguished as 'PAH-type' and 'heavy metal-type' samples. PVC, PU and PS samples showed the highest toxicity in the Vibrio and Daphnia assays. The PVC sample was characterized by an extremely high cadmium concentration (22.4 µg/L), PS, PP and PU samples on the contrary had high total PAH content. While Vibrio and Daphnia showed comparable sensitivity, the phytotoxicity assay had no response for any of the samples tested. Samples originating from the controlled burning of different plastic types such as PU, PVC, PS and PP were classified as genotoxic, PS sample showed extremely high genotoxicity. Genotoxicity expressed as SOSIF showed strong correlation with most of the PAHs detected.

Asunto(s)

RESUMEN

Boiling water before drinking or using it for cooking is a general practice especially in areas where portable water is not readily available. However, boiling water in an aluminum pot could be a route of entry of heavy metals into humans. This study assessed the genotoxic and mutagenic potential of boiled water samples from aluminum pots of different duration of use using the SOS chromotest on Escherichia coli PQ37 and the Ames fluctuation test on Salmonella typhimurium strains TA98 and TA100, respectively. Three aluminum pots from the same manufacturer but of different years of use (6-year-old, 3-year-old, and new aluminum pots) were used for the experiment. Six selected heavy metals (Cadmium, Copper, Arsenic, Nickel, Lead, and Aluminum) were also analyzed in the samples using an Atomic Absorption Spectrophotometer (AAS Buck, Scientific model 210 VGP). Cadmium, Copper, Arsenic, Nickel, Lead, and Aluminum were present in all the test water samples at concentrations that were higher than the maximum limit allowable by standard regulatory organizations. The concentrations of these metals in the samples also increased as the duration of use of the aluminum pots increased. The results further showed that the water boiled in the three aluminum pots is mutagenic and genotoxic in both Ames fluctuation and SOS chromotests. The 6-year-old aluminum pot induced the highest mutagenicity and genotoxicity followed by the 3-year-old aluminum pot. The metals in the tested samples were believed to be responsible for the observed mutagenicity and genotoxicity in the microbial assays. The findings of this study revealed that cooking with Aluminum pots could lead to the leaching of heavy metals into food, and pose mutagenic and genotoxic risks to consumers.

RESUMEN

INTRODUCTION: Plants can be sources of photoprotective/antigenotoxic compounds that prevent cellular mutations involved in skin cancer and aging by regulating UV-induced mutability. PURPOSE: The study was aimed at investigating the sunscreen properties of plants growing in Colombia. MATERIALS AND METHODS: Ultraviolet (UV) radiation-absorption capability of different plant extracts was examined. In vitro photoprotection efficacies were evaluated using in vitro indices such as sun protection factor (SPFin vitro) and critical wavelength (λc). Pearson correlation analysis was used to examine the relationship between SPFin vitro and complementary UVB- antigenotoxicity estimates (%GI) based on the SOS Chromotest database. The cytotoxicity in human fibroblasts was studied using the trypan blue exclusion assay. Major compounds of promising plant extracts were determined by gas chromatography coupled to mass spectrometry (GC/MS). RESULTS: We showed that plant extracts have sunscreen properties against UVB, whereas broad-spectrum radiation protection efficacy was poor. SPFin vitro and %GI were correlated (R = 0.71, p < .0001) for the plant extracts under study. Three extracts obtained from Achyrocline satureioides, Chromolaena pellia, and Lippia origanoides species resulted to possess high protection efficacy and relatively low cytotoxicity in human fibroblasts. These plant extracts contained major compounds such as α-pinene, trans-ß-caryophyllene, γ-muurolene, γ-cadinene and caryophyllene oxide in A. Satureioides extract, trans-ß-caryophyllene, caryophyllene oxide, squalene and α-amyrin in C. pellia extract, and p-cymene, carvacrol, trans-ß-caryophyllene and pinocembrin in L. origanoides extract. CONCLUSIONS: Plants growing in Colombia contain compounds that can be useful for potential sunscreens. SPFin vitro and %GI estimates were correlated, but %GI estimates were more sensitive to detecting activity at lower plant extract concentrations. Our results supported the need to use DNA damage detection assays as a complement to photoprotection efficacy measurement.

Asunto(s)

RESUMEN

DNA is exposed to the attack of several exogenous agents that modify its chemical structure, so cells must repair those changes in order to survive. Alkylating agents introduce methyl or ethyl groups in most of the cyclic or exocyclic nitrogen atoms of the ring and exocyclic oxygen available in DNA bases producing damage that can induce the SOS response in Escherichia coli and many other bacteria. Likewise, ultraviolet light produces mainly cyclobutane pyrimidine dimers that arrest the progression of the replication fork and triggers such response. The need of some enzymes (such as RecO, ExoI and RecJ) in processing injuries produced by gamma radiation prior the induction of the SOS response has been reported before. In the present work, several repair-defective strains of E. coli were treated with methyl methanesulfonate, ethyl methanesulfonate, mitomycin C or ultraviolet light. Both survival and SOS induction (by means of the Chromotest) were tested. Our results indicate that the participation of these genes depends on the type of injury caused by a genotoxin on DNA.

Asunto(s)

RESUMEN

This paper reports the first data from an integrated study investigating genotoxicity in the Brantas River, Java, Indonesia. Results showed that organic sediment extracts from the sites in the Brantas Delta retained genotoxic compounds identified using the SOS Chromotest and that the Aloo River and, to a lesser extent, the Surabaya River were the most contaminated studied sites. This genotoxicity was attributable to compounds that did not require any bioactivation under the test conditions. Occurrence of genotoxic effects was further investigated in erythrocytes from Nile tilapia, Oreochromis niloticus. High numbers of micronuclei were counted, especially in fish sampled in the rivers of the Brantas Delta. Moreover, cytoplasmic alterations which could be indicative of the presence of lipofuscin were found in the cytoplasm of the fish blood cells, especially in fish from the Aloo, Surabaya and Kalimas rivers. Altogether, our data showed that genotoxicity is occurring in fish living in rivers of the delta of the Brantas River and suggest that sediments from these sites may constitute a major source of pollution and hazard for species living or feeding in the area.

Asunto(s)

RESUMEN

Nowadays, the interest in the role of dietary components able to influence the composition and the activity of the intestinal microbiota and, consequently, to modulate the risk of genotoxicity and colon cancer is increasing in the scientific community. Within this topic, the microbial ability to have a protective role at gastrointestinal level by counteracting the biological activity of genotoxic compounds, and thus preventing the DNA damage, is deemed important in reducing gut pathologies and is considered a new tool for probiotics and functional foods. A variety of genotoxic compounds can be found in the gut and, besides food-related mutagens and other DNA-reacting compounds, there is a group of pollutants commonly used in food packaging and/or in thousands of everyday products called endocrine disruptors (EDs). EDs are exogenous substances that alter the functions of the endocrine system through estrogenic and anti-estrogenic activity, which interfere with normal hormonal function in human and wildlife. Thus, this paper summarizes the main applications of probiotics, mainly lactobacilli, as a bio-protective tool to counteract genotoxic and mutagenic agents, by biologically inhibiting the related DNA damage in the gut and highlights the emerging perspectives to enlarge and further investigate the microbial bio-protective role at intestinal level.

Asunto(s)

RESUMEN

Surface waters may contain varying levels of wastewater effluent associated with de facto reuse, which may influence their toxicological properties both prior to and following treatment. This study examined the genotoxic response of three surface waters containing a range of wastewater effluent (5%, 10%, and 25% by volume). The SOS Chromotest™ was used to assay the genotoxicity of both chlorinated and unchlorinated mixtures. Chlorinated mixtures were also analyzed for trihalomethanes (THMs), haloacetonitriles (HANs), and halonitromethanes (HNMs); their concentrations were used to calculate a relative toxicity index for each sample, based on published potencies in the comet assay and subsequently referred to as predicted genotoxicity. Wastewater effluents were observed to be reactive in the genotoxicity assay, whereas raw and chlorinated surface waters were not. Upon chlorination, surface waters containing 5% or 10% wastewater did not elicit a response and only modest effects were observed for higher wastewater ratios (25%). The measured SOS responses correlated well with predicted genotoxicity (R = 0.92) and THM concentrations (R = 0.92). This is important since THMs themselves are non-reactive in either the SOS or comet genotoxic assays, but their formation may serve as surrogates for non-regulated DBPs which drive toxic effects.

Asunto(s)

RESUMEN

Increase in production of different types of plastics has led to increase in the amount of plastic waste generation worldwide. The chemical constituents of these plastic wastes have made their disposal an important economic and environmental health problem globally. This study assessed the mutagenic and genotoxic potential of plastic waste dumpsite raw and simulated leachates using the Ames Salmonella fluctuation test with Salmonella typhimurium strains TA98 and TA100, and the SOS chromotest with Escherichia coli PQ37. Physico-chemical parameters and organic constituents of the leachates were also analyzed. The result of the Ames test showed that the leachates are mutagenic even at low concentration. Also, the TA100 strain was the more responsive strain in terms of mutagenic index in the absence of metabolic activation. The SOS chromotest results complimented the Ames Salmonella fluctuation test results. Nevertheless, the E. coli PQ37 system was slightly more sensitive than the Salmonella assay for detecting mutagens and genotoxins in the tested leachates. Generally, simulated leachate showed a higher mutagenicity and genotoxicity than the raw leachate. Pb, Cd, Cr, Ni, Cu, As, PBDEs, PAHs, PCBs, and Bisphenol A contents analyzed in the leachates were believed to play significant role in the observed mutagenicity and genotoxicity in the microbial assays. These data showed that plastic waste constituents are capable of inducing DNA damage in exposed organisms and might induce similar damage in plants, animals and humans exposed to it, hence, great care should be taken to eliminate indiscriminate disposal of plastics in the environment.

Asunto(s)

RESUMEN

Tunisia water resources are limited. The country currently has 29 large dams, more than 1000 hill lakes, and 220 small dams which are essential for economic and social development given their contribution to irrigation, drinking water consumption, flooding protection, production of electrical energy, groundwater recharge, and industrial uses. Given the scarcity of these resources, it is crucial to be able to ensure the quality of freshwater environments, particularly those intended for human consumption. In this study, we meant to assess the health status of various freshwater ecosystems in different regions of Tunisia (north and center west) in order to detect genotoxic components in sediments and their potential effect on zooplankton (cladocerans). Sediment and cladoceran species were collected from dams, ponds, and temporary rivers in Tunisia. For each collection site, micronucleus (MN) assay was performed, in triplicates, using a pool of ten specimens of the same cladoceran species. MN occurrence in cladocerans varied from one site to another and MN frequencies varied between 0.67 and 22‰, suggesting the presence of genotoxic substances in certain sites. Sediment genotoxicity and mutagenicity were assessed using the SOS Chromotest and the Ames test. Sediment results showed that genotoxicity varies from one site to another displaying a quantitative and a qualitative variation of pollutant among the sites. These results suggest an urgent need for continuous monitoring of freshwater environments in Tunisia, particularly those intended for drinking water.

Asunto(s)

RESUMEN

Genotoxic compounds, as common contaminants of the air environment, are of interest in air pollution monitoring. There are several methods to determine the level of these contaminants in different localities, many of which may be difficult to access with the use of conventional active and passive samplers. In the present study, the needles Pinus mugo Turra and Picea abies were used to monitor sampling localities in Austria, Slovakia, and the Czech Republic. Needles were extracted and chemical analysis and the genotoxicity bioassay SOS chromotest were used to obtain complex information about the chemical mixture of pollutants present and their genotoxic effects. The SOS chromotest method was optimized by using a CPRG chromogenic substrate to reduce the false positive genotoxic effect of needle extracts. Pinus mugo Turra and Picea abies were identified as suitable passive sampling matrices for long-term air monitoring using the same plants sampled at the same time. The presented study brings an innovative method for the fast screening and identification of localities loaded by genotoxic active air contaminants.

Asunto(s)

RESUMEN

Lactic acid bacteria and yeasts, representing the prevailing microbiota associated with different foods generally consumed without any cooking, were identified and characterized in vitro for some functional properties, such as acid-bile tolerance and antigenotoxic activity. In particular, 22 Lactobacillus plantarum strains and 14 yeasts were studied. The gastro-intestinal tract tolerance of all the strains was determined by exposing washed cell suspensions at 37°C to a simulated gastric juice (pH 2.0), containing pepsin (0.3% w/v) and to a simulated small intestinal juice (pH 8.0), containing pancreatin (1 mg mL-1) and bile extract (0.5%), thus monitoring changes in total viable count. In general, following a strain-dependent behavior, all the tested strains persisted alive after combined acid-bile challenge. Moreover, many strains showed high in vitro inhibitory activity against a model genotoxin, 4-nitroquinoline-1-oxide (4-NQO), as determined by the short-term method, SOS-Chromotest. Interestingly, the supernatants from bacteria- or yeasts-genotoxin co-incubations exhibited a suppression on SOS-induction produced by 4-NQO on the tester strain Escherichia coli PQ37 (sfiA::lacZ) exceeding, in general, the value of 75%. The results highlight that food associated microorganisms may reach the gut in viable form and prevent genotoxin DNA damage in situ. Our experiments can contribute to elucidate the functional role of food-associated microorganisms general recognized as safe ingested with foods as a part of the diet.

RESUMEN

The inappropriate and unsafe management practices related to disposal and recycling of electronic wastes in Nigeria has led to environmental and underground water contamination. Reports on the level and type of contamination as well as the possible DNA damage effects of this contamination are insufficient. This study evaluated the DNA damaging potential of e-waste simulated and raw leachates, and its contaminated underground water using the SOS chromotest on Escherichia coli PQ37 and the Ames Salmonella fluctuation test on Salmonella typhimurium strains TA98 and TA100, without and with metabolic activation. Physico-chemical parameters of the samples were also analyzed. The result of the Ames test showed induction of base pair substitution and frameshift mutation by the test samples. However, the TA100 was the more responsive strain for the three samples in terms of mutagenic index in the absence and presence of metabolic activation. The SOS chromotest results were in agreement with those of the Ames Salmonella fluctuation test. Nevertheless, the E. coli PQ37 system was slightly more sensitive than the Salmonella assay for detecting genotoxins in the tested samples. Lead, cadmium, manganese, copper, nickel, chromium, arsenic, and zinc contents analyzed in the samples were believed to play a significant role in the observed DNA damage in the microbial assays. The results of this study showed that e-waste simulated and raw leachates, and its contaminated underground water are of potential mutagenic and genotoxic risks to the exposed human populace.

Asunto(s)

RESUMEN

In this work, the main objectives were to assess the mutagenic and genotoxic effects of fine particulate matter collected in an industrial influenced site in comparison with a non-industrial influenced one (rural site) and to relate the particulate matter (PM) composition to the observed genotoxic effects. At the industrial influenced site, higher concentrations of phosphates, trace metals, and polycyclic aromatic hydrocarbons (PAHs) in particles could be related to the contributions of quarries, fertilizer producer, cement plants, and tires burning. Gasoline and diesel combustion contributions were evidenced in particles collected at both sites. Particles collected under industrial influence showed a higher mutagenic potential on three tested strains of Salmonella typhimurium (TA98, YG1041, and TA102), and especially on the YG1041, compared to particles from the rural site. Furthermore, only particles collected in the vicinity of the industrial site showed a tendency to activate the SOS responses in Escherichia coli PQ37, which is indicative of DNA damage as a result of exposure of the bacteria cells to the action of mutagenic samples. The mutagenicity and genotoxicity of the industrial PM2.5-0.3 particulates may be attributed to its composition especially in organic compounds. This study showed that proximity of industries can affect local PM composition as well as PM genotoxic and mutagenic potential.

Asunto(s)

RESUMEN

This study evaluates the toxicity and genotoxicity levels of atmospheric particulate matter (PM) samples collected at several locations of a megacity (Istanbul, Turkey) with different urban and industrial characteristics. The ambient air samples, in the form of a coarse fraction of inhalable particulates, PM2.5-10, were collected on Teflon filters using a passive sampling method on a monthly basis during a one-year period. Later, they were extracted into both the lipophilic and hydrophilic phases using dimethyl sulfoxide (DMSO) and ultra-pure water, respectively. The obtained aqueous extracts were tested for acute toxicity and genotoxicity using the photo-luminescent bacterium Vibrio fischeri Microtox® and SOS Chromotest® assays, respectively. Statistically significant differences greater than background levels were obtained in both measurements, indicating the presence of toxic substances absorbed on particulate matter. The PM2.5-10 extracts identified significant seasonal and locational differences in the toxicity and genotoxicity levels. Local anthropogenic activities and factors were associated with the quantified higher levels. Finally, a qualitative inner comparison study of regional toxicity and genotoxicity indexes was suggested to provide a clearer picture of the pollution and risk levels (or occurrences) in the Istanbul urban area. In this indexing study, the threshold levels for the urban background and episodic occurrences of the toxicity and genotoxicity levels in PM2.5-10 samples were identified to be 1.11 TU (Toxicity Unit) and 8.73 TU and 0.72 IF (Induction Factor) and 1.38 IF, respectively.

Asunto(s)