Genotoxicity of total and fractionated extractable organic matter in fine air particulate matter from urban Guangzhou: comparison between haze and nonhaze episodes

To investigate the genotoxic potencies of extractable organic matter (EOM) in aerosols, fine air particulate matter (PM(2.5)) was collected simultaneously at a roadside (1.2 m above ground) and at a rooftop location (50 m above ground) in urban Guangzhou (China) during a nonhaze period in September 2006 and a haze period in October 2006. Particle-bound organics were extracted and separated into aliphatic, aromatic, and polar fractions. The genotoxicity of total and fractionated extracts were tested by single-cell electrophoresis (comet assay) with human blood lymphocytes. The PM(2.5) concentrations usually exceeded the U.S. National Ambient Air-Quality Standard level (65 microg/m(3)) at both the roadside and the rooftop. During nonhaze days, the roadside samples showed substantially higher PM(2.5) levels (108-130 microg/m(3)) and significantly higher genotoxic effects of total and fractionated EOM (p < 0.05 for >10 m(3) air equivalent/ml) than the rooftop samples. During haze days, however, PM(2.5) levels and genotoxic potencies of rooftop samples were drastically elevated and comparable to those of roadside samples, implying that during haze episodes, most people in the urban area are exposed to PM(2.5) pollution as serious as in the heavily polluted roadside microenvironment. All total EOM samples showed significant (p < 0.05) dose-response effects, and their effects as olive tail moment were less than the sums of the three fractions. Aromatic fractions of EOM exhibited the greatest genotoxic potencies, but polar fractions also contributed substantially to DNA-damaging effects. Polycyclic aromatic hydrocarbons and nitrated derivatives likely are the most important species responsible for the genotoxicity of EOM in PM(2.5).     

Soil contamination detected using bacterial and plant mutagenicity tests and chemical analyses

Soil contaminants are common in industrialized countries, causing widespread contamination directly of soil and indirectly of ground water and food. Among these pollutants particular attention should be paid to soil mutagens and carcinogens due to their potentially hazardous effects on animal populations and human health. The aim of this research was to evaluate the genotoxicity of contaminated soils by means of an integrated chemical/biological approach, using a short-term bacterial mutagenicity test (Ames test), a plant genotoxicity test (Tradescantia/micronucleus test), and chemical analyses. Soil samples were collected in a highly industrialized area in the Lombardy region, in Northern Italy. Soil samples were extracted with water or with organic solvents. Water extracts of soil samples were tested using the Tradescantia genotoxicity test and organic solvent extracts were analyzed for their polycyclic aromatic hydrocarbon (PAH) concentrations and for their mutagenicity with the Ames test. Heavy metal concentrations were also studied. Some soil samples showed mutagenic activity with the Ames test and clastogenicity with the Tradescantia/micronucleus test. The same soils showed high concentrations of genotoxic PAH and heavy metals.     

PM<Subscript>2.5</Subscript> and Associated Polycyclic Aromatic Hydrocarbon and Mutagenicity Emissions from Motorcycles

In this study, PM(2.5) in diluted exhausts of motorcycles are collected and emission characteristics of PM(2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and mutagenicities are investigated. The measured mutagenicity emission factors with metabolic activation for new fuel injection, used fuel injection, new carburetor and used carburetor motorcycles are 7.77 x 10(4), 1.18 x 10(5), 1.32 x 10(5) and 1.15 x 10(5) rev/km, respectively. The mutagenicity emission factors with metabolic activation are higher than the corresponding values without metabolic activation. The average PAH emission factors are 12.3, 16.3, 25.5 and 26.5 mug/km for new and used fuel-injection motorcycles, and new and used carburetor-operated motorcycles, respectively. The correlation coefficients between PAHs and mutagenicity emission factors are higher with metabolic activation (0.59) than that without metabolic activation (0.31).     

The mutagenic hazards of environmental PM2.5 in Turin

Owing to the large number of natural and anthropogenic sources, particulate matter (PM) may present several physical and chemical patterns in different areas. The finer PM2.5 fraction, which is now widely but not routinely measured in Europe, is considered to be the alveolar fraction of the ambient particles. Annual and winter mean concentrations of PM2.5 substantially vary in Europe, with higher concentrations in the South. The aims of this work were to (a) measure the PM2.5 levels in Turin over a long period, (b) evaluate mutagenic activities of organic extracts containing this collected complex mixture using the Ames test and (c) determine the level of polycyclic aromatic hydrocarbons (PAHs) in order to identify important mutagens in ambient air. Sampling was carried out from November 2001 to December 2004. The monthly mean of PM2.5 was 48.76+/-24.12 microg/m3. From the beginning to the end of the sample period there was a decrease in gravimetric levels, with annual means of 54.10+/-29.77 microg/m3 in 2002; 42.48+/-15.73 microg/m3 in 2003 and 45.89+/-24.92 microg/m3 in 2004. Samples were tested for mutagenicity using Salmonella typhimurium strains TA98 and TA100, with and without S9 mix metabolic activation. A positive genotoxic response was observed for TA98, with and without metabolic activation. The measured PAHs monthly mean level was 8.24+/-6.30 ng/m3, with values ranging from 0.20 to 21.38 ng/m3 Seasonal variation of gravimetric, mutagenic and PAH values was significant. The Salmonella assay results statistically correlated to PM2.5 and PAHs levels, but sometimes the mutagenic potencies were rather different despite an equal concentration of pollutant. The results confirm the usefulness of this biological approach to detect genotoxic properties of sampled PM2.5 and they show the variability of the mutagenic properties of the airborne mixture over time.     

Concentrations of Atmospheric Polycyclic Aromatic Hydrocarbons in Particulate Matter and the Gaseous Phase at Roadside Sites in Hanoi,Vietnam

We analyzed the concentrations of polycyclic aromatic hydrocarbons (PAHs) in both particulate matter (PM) and the gaseous phase at 10 roadside sites in Hanoi, Vietnam. The average concentrations of 47 PAHs ( summation 47PAHs) were 63 +/- 82 ng m(-3) in PM and 480 +/- 300 ng m(-3) in the gaseous phase. The PAHs mainly originated from motorcycles without catalytic converters. The highest concentrations of summation 47PAHs in both PM and the gaseous phase were observed at a terminal for buses and trucks. The operation of large commercial vehicles led to increased PAH pollution at the terminal site.     

Artificial Turf Football Fields: Environmental and Mutagenicity Assessment

The public has recently raised concerns regarding potential human health and environmental risks associated with tire crumb constituents in the artificial turf of football fields. The aim of the present study was to develop an environmental analysis drawing a comparison between artificial turf football fields and urban areas relative to concentrations of particles (PM10 and PM2.5) and related polycyclic aromatic hydrocarbons (PAHs), aromatic hydrocarbons (BTXs), and mutagenicity of organic extracts from PM10 and PM2.5. No significant differences were found between PM10 concentrations at an urban site and on a turf football field, both during warm and in cold seasons, either with or without on-field activity. PM2.5 concentrations were significantly greater at the urban site in the cold season as was the ratio of PM2.5 to PM10. BTXs were significantly greater at urban sites than on turf football fields on both on warm and cold days. The ratio of toluene to benzene (T/B ratio) was always comparable with that of normal urban conditions. The concentration of PAHs on the monitored football fields was comparable with urban levels during the two different sampling periods, and the contribution of PAHs released from the granular material was negligible. PM10 organic extract mutagenicity for artificial turf football fields was greater, whereas PM2.5 organic extract mutagenicity was lower, compared with the urban site studied. However, both organic extract mutagenicity values were comparable with the organic extract mutagenicity reported in the literature for urban sites. On the basis of environmental monitoring, artificial turf football fields present no more exposure risks than the rest of the city.     

PAH Content and Mutagenicity of Marine Sediments from the Venice Lagoon

Sediments from the Venice lagoon, a polluted coastal environment in northeastern Italy, were assayed for mutagenicity and content of several toxic microcontaminants, which included selected polycyclic aromatic hydrocarbons (PAHs); the latter are specifically dealt with in this paper. Samples were collected at three lagoon sites with reasonably distinct environmental features—urban, industrial, or agricultural—and at two others considered to be under mixed pollution influences; a sixth sample was obtained from an open sea area to act as background control. The organic matter (EOM) associated with the mineral substrata was extracted; after cleanup, analyte determination was carried out by HRGC-LRMS(SIM) using isotopically labeled compounds as internal standards. Cumulative levels of the selected PAHs were found to be in the range of 0.065 to 0.46 μg/g of dry matrix at five sites; a much higher concentration (48 μg/g) was detected in the sample from the urban environment. The remarkable PAH level increase at this site was mostly accounted for by the concurrent, apparent increase of EOM contamination as PAH concentration was seen to reach 32 μg/mg of EOM from <1 μg/mg at the five remaining sites. Mutagenicity assays withSalmonella typhimuriumstrains TA98 and TA100 of marine sediment organic extracts also highlighted a distinct activity in the sample from the urban site. Further fractionation and analysis of this extract pointed to PAHs as the main mutagenic component present in the sediment matrix, possibly accounting for up to approximately 70–80% of the entire mutagenic potential detected.     

乙醇-柴油混合燃料排放物的遗传毒性检测及分析

目的了解在柴油中掺烧不同比例乙醇对柴油机工作时污染排放的影响,为寻找节能、低污染汽车燃料提供科学依据。方法采用Ames试验、彗星试验及色谱-质谱联用仪对不同比例乙醇-柴油(体积比为0∶100、5∶95、10∶90、20∶80)混合燃料排放颗粒提取物(E0、E5、E10、E20)进行了遗传毒性检测和16种多环芳烃测定及分析。结果不同比例乙醇-柴油混合燃料燃烧后排放颗粒提取物在Ames试验和彗星试验中均为阳性反应,表明其具有明显的致基因突变及DNA损伤作用。其中不掺烧乙醇的柴油排放物(E0)遗传毒性作用明显,掺体积分数为5%的乙醇的排放物(E5)遗传毒性降低,增加掺烧乙醇的比例,排放物的毒性作用又逐渐增强。多环芳烃的测定结果显示,不掺烧乙醇排放物比排量较高(77.19μg·kw-1·h-1),掺烧体积分数为5%的乙醇可降低比排放量(62.43μg·kw-1·h-1),增加掺烧乙醇比例,比排量又出现明显的增加(107.15μg·kw-1·h-1)。其结果与基因突变试验和DNA损伤试验结果有一定的正相关。结论与纯柴油或高比例掺烧乙醇相比较,掺燃体积分数为5%的乙醇的柴油燃料可降低燃烧排放物中多环芳烃的比排放量和燃烧排放物的遗传毒性。     

Polycyclic aromatic hydrocarbons and their quinones modulate the metabolic profile and induce DNA damage in human alveolar and bronchiolar cells

The release of particulate pollutants into the air through burning of coal, crude oil, diesel, coal tar, etc. raises concerns of potential health hazards to the exposed human population. Polycyclic aromatic hydrocarbons (PAHs) are major toxic constituents of particulate matter (PM), which upon ingestion get metabolized to even more toxic metabolites such as quinones. The PAHs levels were assessed in both respirable particulate matter (RSPM, <10 μM size) and suspended particulate matter (SPM, >10 μM size) of urban ambient air (UAA) and that of major contributors viz. diesel exhaust particles (DEPs) and coal tar combustions emissions (CTCE). Seven US Environmental Protection Agency (USEPA) prioritized PAHs in RSPM and 10 in SPM were detected in UAA. Ten and 15 prioritized PAHs, respectively, were also detected in diesel exhaust particles (DEP) and coal tar combustion emission (CTCE) evidencing their release in the air. These PM associated PAHs for UAA, DEP and CTCE showed significant increase (p < 0.05) in mutagenicity and mammalian genotoxicity in the order CTCE > DEP > UAA. Human lung alveolar (A549) and bronchiolar (BEAS-2B) cells when treated with PAH-metabolites viz. 1,4-benzoquinone (1,4-BQ), hydroquinone (HQ), 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ) and 9,10-phenanthroquinone (9,10-PQ) showed metabolic modulation in these cell lines with significant depletion of principal cellular metabolites viz. NADP, uracil, asparagines, glutamine, and histidine and accumulation of di-methyl amine and beta-hydroxybutyrate, identified using ¹H NMR spectroscopy. These results suggest that PAH-quinones induce genotoxic effects by modulating the metabolic machinery inside the cells by a combined effect of oxidative stress and energy depletion. Our data for metabolic profiling of human lung cells could also help in understanding the mechanism of toxicity of other xenobiotics.     

Assessment of the mutagenic potency of sewage sludges contaminated with polycyclic aromatic hydrocarbons by an Ames sludges for fluctuation assay

The mutagenicity of crude extracts and subfractions of two samples of a reference sewage sludge material and two sewage sludges from two wastewater treatment plants (WWTP), one urban and the other one urban mixed with industrial, was assessed using an Ames fluctuation assay based on 384-well microtiter plates with liquid cultures. Crude extracts of sludges were obtained by ultrasonic extraction with dichloromethane/methanol, and further column fractionation yielded two fractions, one of which containing mutagenic polycyclic aromatic hydrocarbons (PAHs). Quantitative analysis performed by gas chromatography-mass spectrometry gave sum concentrations of the 16 PAHs listed as priority pollutants by the U.S. Environmental Protection Agency at levels between 1,305 and 2,442 microg/kg. Subjecting crude extracts and column fractions to the mutagenicity assay with Salmonella strains TA98 and TA 100 provided good qualitative correlation between the presence of mutagenic PAH and the induction of gene mutations. In general, the crude extracts and the PAH-fractions induced positive responses in the assay with both bacterial strains on metabolic activation by S9 rat-liver homogenate, whereas direct-acting mutagens were not detectable. In the assay with the real sludge samples of two different WWTPs, TA98 proved to be more sensitive than TA100; however, similar sensitivities of the tester strains were observed for two reference sewage sludge materials of the same origin. The outcomes of the Ames fluctuation assay demonstrated its performance as a cost-effective and relatively rapid screening tool to assess the genotoxic potential of complex environmental samples.     

Determination of genotoxic polycyclic aromatic hydrocarbons in a sediment from the Black River (Ohio)

Polycyciic aromatic hydrocarbons (PAH) have been identified as genotoxic pollutants in sediment from the Black River, Ohio, where a high incidence of hepatoma was observed in brown bull-head catfish (Ictalurus nebulosus). Subfractions of PAH based on the number of aromatic carbons were isolated from the PAH fraction of a Black River sediment extract. Ten subfractions were analyzed by capillary column gas chromatographymass spectrometry, tested for mutagenicity using the Ames assay, and tested for induction of unscheduled DNA synthesis (UDS) in primary rat hepatocytes. The Ames assay indicated significant mutagenic activity in fractions which contained PAH with 4–6 aromatic rings; the majority of the activity was found in the fraction composed of 5-ring compounds. UDS was also significant in the same fractions, although the greatest genotoxicity was observed in thecata-condensed andperi-condensed 4-ring fractions which contained a large amount of alkylated-PAH.Contribution of the National Bureau of Standards, not subject to copyright     

Influence of traffic patterns on particulate matter and polycyclic aromatic hydrocarbon concentrations in Roxbury,Massachusetts

Vehicle emissions have been associated with adverse health effects in multiple epidemiological studies, but the sources or constituents responsible have not been established. Characterization of vehicle-related exposures requires detailed information on spatial and temporal trends of various pollutants and the ability to predict exposures in unmonitored settings. To address these issues, in the summer of 2001 we measured continuously particle-bound polycyclic aromatic hydrocarbons (PAHs), ultrafine particles, and PM(2.5) at a number of sites in Roxbury, a neighborhood of Boston, Massachusetts with significant diesel and gasoline-fueled traffic. We took measurements at the side of the road and at varying distances from the road, with simultaneous collection of traffic counts and meteorological conditions. Across all nine sites, median roadside concentrations were 8 ng/m(3) of particle-bound PAHs (range: 4-57), 16,000 ultrafine particles/cm(3) (range: 11,000-53,000), and 54 microg/m(3) of PM(2.5) as measured with a DustTrak (range: 12-86). Concentrations of all pollutants were lower at greater distances from the road, upwind, and at higher wind speeds, with greater concentration gradients for PAHs and ultrafine particles. In linear mixed effects regression models accounting for temporal autocorrelation, large diesel vehicle counts were significantly associated with roadside concentrations of PAHs (P=0.02), with a moderate association with ultrafine particles and little relation with PM(2.5). Although more comprehensive information would be needed for epidemiological applications, these data demonstrate significant spatial and temporal heterogeneity for traffic-related pollutants during the summer in an urban center, with our monitoring and analytical methodology helping to inform source attribution.     

In situ biomonitoring of PAH-contaminated sediments using juvenile coho salmon (Oncorhynchus kisutch)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous marine and freshwater sediment contaminants. Extensive data exist to confirm that PAHs are toxic to aquatic receptors. However, limited information is available regarding the bioavailability and genotoxicity of sediment PAHs to aquatic organisms. This study investigated an integrated biomonitoring approach using chemical analyses and biomarkers to characterize the bioavailability and genotoxicity of a complex PAH mixture in freshwater lake sediments associated with a former manufactured gas plant (MGP). Sediment PAH genotoxicity was assessed by flow cytometry (FCM), DNA adduct (32)P-postlabeling, and erythrocyte micronuclei in juvenile coho salmon (Oncorhynchus kisutch) caged in the water column. Significant PAH-induced genotoxicity was observed with FCM and (32)P-postlabeling, but not with erythrocyte micronuclei. Chromosome damage in peripheral blood and hepatic DNA adducts correlated with sediment, but not water column PAH concentrations. Total hepatic DNA adducts in salmon caged nearest the former MGP facility was 39+/-6.5 (RALx10(9)), while salmon caged in a reference lake had 28+/-2.3 total hepatic DNA adducts per 10(9) nucleotides. These results indicate that in situ biomonitoring using biomarkers and caged fish can be a sensitive indicator of genotoxic PAHs in sediments.     

Mutagenicity and genotoxicity of coal fly ash water leachate

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals-sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significant (P<0.05) concentration-dependent increases in DNA damage in whole blood cells, lymphocytes, and in Nicotiana plants. The comet parameters show increases in tail DNA percentage (%), tail length (mum), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.     

Levels of polycyclic aromatic hydrocarbons (PAHs) in air samples in the city of Arezzo (1997-1998)

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environment pollutants of air, water and soil. Since many PAHs are potent mutagens and/or carcinogens the occurrence of these compounds in the lower atmosphere is an important element of environmental pollution. We measured PAH levels in airborne particles collected in the town of Arezzo, (Tuscany, Italy), during the period April 1997-February 1998. Air monitoring for 24 h was repeated for 7 days, during two weeks, in each season; a total of 84 air samples were obtained sampling two urban sites where the traffic is the main source of pollution. One site is a residential area. The data of this study indicate a pronounced seasonal variation in PAH levels and show that in cold spells other sources of contamination besides vehicular traffic are important.     

Mutagenicity, Genotoxicity, and Estrogenic Activity of River Porewaters

We investigated mutagenicity, genotoxicity, and estrogenic activity in the porewaters of two river basins in southern Italy that had different features. Three samples from each site were collected in different seasons from 7 sites for a total of 21 samples. Mutagenicity was measured with the Ames test with and without metabolic activation (S9) using Salmonella typhimurium TA98 and TA100 strains. Genotoxicity was measured with two tests: one involved a chromophore that detected DNA damage in Escherichia coli PQ37 (SOS chromotest), and the other measured micronuclei formation in the root cells of Vicia faba. Estrogenic activity was measured with a yeast-based estrogen receptor assay and an MCF-7 cell-based, estrogen-sensitive proliferation assay. We also applied chemical analyses to detect alkylphenols, pesticides, natural and synthetic hormones, and heavy metals. The porewaters of both river sediments showed mutagenic/genotoxic activity on V. faba test and Ames test, the latter both with and without S9 liver fraction. The SOS chromotest without metabolic activation was not sufficiently sensitive to detect genotoxicity of the porewaters, but the SOS DNA repair system in E. coli PQ37 was activated in the presence of S9 mix. Good correlations were found between mutagenicity/genotoxicity and the concentration of cadmium and between estrogenic activity and the presence of copper. This study assessed the chemical concentrations of some bioavailable pollutants in porewater and detected the overall effects of multiple pollutants that contributed to mutagenicity, genotoxicity, and estrogenic activity of these two basin porewaters, thus increasing our understanding of the environmental consequences of polluted aquatic ecosystems.     

Photoirradiation of representative polycyclic aromatic hydrocarbons and twelve isomeric methylbenz[a]anthracene with UVA light: formation of lipid peroxidation

Polycyclic aromatic hydrocarbons (PAHs) are widespread genotoxic environmental pollutants, which require metabolic activation in order to exert biological activities, including mutagenicity and carcinogenicity. Photoactivation is another activation pathway that can lead to PAH genotoxicity. In this paper, we demonstrate that photoirradiation of a series of representative PAHs, with and without bearing a methyl substituent, with UVA light in the presence of methyl linoleate resulted in the formation of methyl linoleate hydroperoxides (a lipid peroxide). The lipid peroxide formation was inhibited by dithiothreitol (DTT) (free radical scavenger), NaN3 (singlet oxygen and free radical scavenger), and superoxide dismutase (SOD) (superoxide scavenger), but was enhanced by the presence of deuterium oxide (D2O) (extends singlet oxygen lifetime). These results suggest that photoirradiation of PAHs by UVA light generates reactive oxygen species (ROS), which induce lipid peroxidation.     

Particle-Size Distribution of Polycyclic Aromatic Hydrocarbons in Urban Road Dust of Masan, Korea

Concentrations and compositions of polycyclic aromatic hydrocarbons (PAHs) in particle size fractions of road dust sampled from contrasting areas of an industrialised city in Korea are reported. The largest amounts of road dust were present in industrial areas, followed by areas subject to heavy traffic, and the lowest amounts were associated with a residential area. The highest concentrations of PAHs were recorded in road dust sampled from the areas with the heaviest traffic (0.45-4.1 μg/g), followed by industrial areas (0.1-3.56 μg/g), with the lowest concentrations associated with a residential area (0.32-1.95 μg/g). PAH concentrations in the fractionated dust from the industrialised areas exhibited an inverse correlation with particle size. Although a similar general pattern was observed in the areas of heavy traffic, some increased concentrations associated with larger particles possibly reflect petrogenic contributions. Particles in road dusts from the residential area were generally smaller than those from the other areas, with PAH composition dominated by pyrogenic sources. PAH compositional profiles, evaluated through diagnostic isomeric ratios, indicate that exhaust emissions, rather than crankcase oils or tire and asphalt abrasion, are the major polluting source.     

Occupational and environmental levels of mutagenic PAHs and respirable particulate matter associated with diesel exhaust in Santiago, Chile

This work studied the mutagenic potential and polycyclic aromatic hydrocarbon (PAH) levels onto PM10 collected in diesel revision plants, in an urban area as well as in a rural area in Santiago, Chile. The PM10 average levels in diesel emission plants during working hours (there is no occupational PM10 Chilean standard) were significantly higher than the atmospheric Chilean PM10 standard and highly mutagenic and with high PAHs levels. Additionally, we evaluated the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-pyrene urinary levels. The diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype. The higher levels of 1-OH-P were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype. This kind of information might be relevant to establish prevention, protection, and mitigation actions to protect public health.     

Columba livia as a Sentinel Species for the Assessment of Urban Air Genotoxicity

This study explored the comet assay as a possible tool to assess genotoxicity in erythrocytes of Columba livia to detect genotoxic effects induced by exposure to urban air pollution. Fieldwork was conducted between June 2004 and June 2005 in the city of Milan, Italy, by sampling pigeons in different areas almost twice a week. Six air contaminants—CO, PM10, NO₂, O₃ (ozone), SO₂, and C6H6—plus polycyclic aromatic hydrocarbons (PAHs) in fine particles, temperature, and ultraviolet index, were considered. Genotoxicity levels, expressed as %DNA migrated, tail moment, and damage index (DI), were always higher in wild pigeons than in pigeons living indoors (controls). Animals exposed to urban air showed significant differences from season to season, and the genotoxic parameters presented the highest values in summer (45.30% ± 1.40% %DNA migrated, 12.73 ± 0.80 tail moment, and 22.30 ± 0.15 × DI × 10⁻¹); regression analyses showed a positive relation between DI and O₃ concentrations (P < 0.001). The use of the comet assay DI parameter as a rapid assessment of incipient genotoxic risk by pollution, as measured in C. livia living in urban areas, is also discussed.