Human biomonitoring of PCDDs, PCDFs, and PCBs in women living in a Northern Italy industrial area.

In Brescia , a highly industrialized city in the Lombardy Region (Northern Italy) classified as a SIN (Contaminated Site of National Interest), a human biomonitoring study was carried out on breast milk of two groups of women residing in areas with presumably different levels of exposure to polychlorodibenzo-p-dioxins, polychlorodibenzofurans, and polychlorobiphenyls. This study was aimed at evaluating the possible difference between women living in Brescia and women living far from it but in the same Region. Between 2016 and 2018, 82 women were enrolled (41 "exposed" subjects and 41 "not exposed"), breast milk samples were collected, and a specific questionnaire was administered to the donors. Data obtained were processed by robust regression and Principal Component Factor Analysis. The differences in concentration between the two groups were significant for all the classes of analytes (except for PCDDs). The concentration increase rates from the not exposed to the exposed group resulted highly significant: some PCB congeners showed increase rates more than 1000 ng/g lb per one-unit change of the independent variable. Among the variables significantly associated with the observed concentrations, age showed the greatest influence, while BMI showed a counteracting effect. Consumption of vegetable oil and fruit resulted to possibly influence the chemicals body burden. For the not exposed group, the levels appear to be in line with the decreasing trend (2001-2018) observed for these contaminants in Italy.

Has Regulatory Action Reduced Human Exposure to Flame Retardants?

Flame retardant (FR) exposure has been linked to several environmental and human health effects. Because of this, the production and use of several FRs are regulated globally. We reviewed the available records of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDDs) in human breast milk from literature to evaluate the efficacy of regulation to reduce the exposure of FRs to humans. Two-hundred and seven studies were used for analyses to determine the spatial and temporal trends of FR exposure. North America consistently had the highest concentrations of PBDEs, while Asia and Oceania dominated HBCDD exposure. BDE-49 and -99 indicated decreasing temporal trends in most regions. BDE-153, with a longer half-life than the aforementioned isomers, typically exhibited a plateau in breast milk levels. No conclusive trend could be established for HBCDD, and insufficient information was available to determine a temporal trend for BDE-209. Breakpoint analyses indicated a significant decrease in BDE-47 and -99 in Europe around the time that regulation has been implemented, suggesting a positive effect of regulation on FR exposure. However, very few studies have been conducted globally (specifically in North America) after 2013, during the time when the most recent regulations have been implemented. This meta-analysis provides insight into global trends in human exposure to PBDEs and HBCDD, but the remaining uncertainty highlights the need for ongoing evaluation and monitoring, even after a compound group is regulated.

Determinants of exposure to polychlorinated biphenyls in the Italian population in the last decades.

Polychlorinated biphenyls (PCBs) are industrial products extensively used in the past. Because of their widespread presence and toxic effects, the international community adopted control measures to reduce their release into the environment. Currently, PCB concentrations are decreasing, but humans are still exposed. In this paper, we reported the results of a study concerning PCB concentrations in human serum samples collected in Italy over two decades. The aim of the study was to investigate the trend of major determinants of PCB human exposure, several decades after the end of their production. PCB concentrations ranged over three orders of magnitude (from 0.4 to 958 ng/g lipid), with a median value of 85 ng/g lipid. We identified age, sampling year, body mass index, sex, and living near hot spots or being occupationally exposed as relevant factors in determining body burden. Our results can give indications to refine regulatory policies on PCBs in Italy, with particular attention to the disposal of residue PCB-containing products. To improve control measures can further decrease the exposure of citizens to PCBs, limit health implications, and improve citizens' perception about chemical risk management.

The Use of Human Biomonitoring to Assess Occupational Exposure to PAHs in Europe: A Comprehensive Review.

Polycyclic aromatic hydrocarbons (PAHs) are among the chemicals with proven impact on workers' health. The use of human biomonitoring (HBM) to assess occupational exposure to PAHs has become more common in recent years, but the data generated need an overall view to make them more usable by regulators and policymakers. This comprehensive review, developed under the Human Biomonitoring for Europe (HBM4EU) Initiative, was based on the literature available from 2008-2022, aiming to present and discuss the information on occupational exposure to PAHs, in order to identify the strengths and limitations of exposure and effect biomarkers and the knowledge needs for regulation in the workplace. The most frequently used exposure biomarker is urinary 1-hydroxypyrene (1-OH-PYR), a metabolite of pyrene. As effect biomarkers, those based on the measurement of oxidative stress (urinary 8-oxo-dG adducts) and genotoxicity (blood DNA strand-breaks) are the most common. Overall, a need to advance new harmonized approaches both in data and sample collection and in the use of appropriate biomarkers in occupational studies to obtain reliable and comparable data on PAH exposure in different industrial sectors, was noted. Moreover, the use of effect biomarkers can assist to identify work environments or activities of high risk, thus enabling preventive risk mitigation and management measures.

Biomonitoring of the adult population in the area of turin waste incinerator: Baseline levels of polycyclic aromatic hydrocarbon metabolites.

Exposure to polycyclic aromatic hydrocarbons (PAHs) was assessed in a cohort of 394 subjects, 198 residing in three small municipalities near a new waste-to-energy (WTE) incinerator located in the Turin area, and 196 residing in neighbouring control areas in the town (of Turin). The assessment of exposure to PAHs was part of a human biomonitoring study aimed at assessing potential incremental exposure to pollutants related to incineration activities through the analysis of such pollutants before the plant start-up, and after one and three years of operation. The exposure assessment described in this study was carried out before the start-up of the WTE incinerator. Ten monohydroxy-PAHs (OH-PAHs) were analyzed in urine samples, consisting in the principal metabolites of naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), and pyrene (PYR). Concentrations of the sum of OH-PAHs (Σ10OH-PAHs) were in the range of 525-85200 ng/g creatinine, with P50 equal to 6770 ng/g creatinine. Metabolites of naphthalene were found at the highest concentrations (P50 values of 892 and 4300 ng/g creatinine for 1- and 2-OH-NAP, respectively) followed by the three OH-FLUs (P50 values of individual compounds in the range of 58.2-491 ng/g creatinine), the four OH-PHEs (P50 values in the range of 30.5-145 ng/g creatinine), and 1-OH-PYR (P50 value of 82.8 ng/g creatinine). Concentrations of 1-OH-NAP, 9-OH-FLU, 1-, 2-, 3, 4-OH-PHE, and 1-OH-PYR were significantly lower in subjects living near the WTE plant compared to those living in the town of Turin, with differences between the two groups in the range 14-31%. Smoking habits markedly influence the urinary concentrations OH-PAHs. Median concentrations of the single metabolites in smokers were from 1.4 fold (for 4-OH-PHE) to 14 fold higher (for 3-OH-FLU) than those observed in non-smokers. The heating system used also resulted to be a major contributor to PAH exposure. Concentrations of OH-PAHs were generally comparable with those observed in other industrialized countries. The profile pattern was consistent with those reported in the literature. Concentrations of OH-PAHs assessed in this study may be considered indicative of the background exposure to PAHs for adult population living in an urban and industrialized area.

Concentrations of polychlorinated dibenzodioxins, polychlorodibenzofurans, and polychlorobiphenyls in women of reproductive age in Italy: A human biomonitoring study.

BACKGROUND: Polychlorinated dibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), and polychlorobiphenyls (PCBs) are persistent organic pollutants that represent a major concern for women of reproductive age because of the neurodevelopmental effects associated to perinatal exposure. OBJECTIVES: This study was aimed at characterizing exposure of women of reproductive age to PCDDs, PCDFs, and PCBs as a function of residence in different Italian Regions, in areas at presumable different environmental contamination and human exposure to these pollutants. METHODS: Study participants were enrolled in 2011-2012 in 6 Italian Regions representative of Northern, Central and Southern Italy; in each region, areas at presumed different exposure (rural, urban and industrial) were selected for enrolment. Each participant provided a serum sample for the analysis of PCDDs, PCDFs and PCBs. RESULTS: Median concentrations of PCDDs+PCDFs, DL-PCBs, NDL6-PCBs and NDL9-PCBs in serum samples were respectively 6.0 and 3.5 pgWHO-TE05/g fat, and 75 and 93ng/g fat. Age was the variable that most affected median serum concentrations. Age adjusted concentrations were found significantly different between geographical zones: women from Northern Italy showed the highest values, followed by Central and Southern Italy. PCDDs+PCDFs concentrations were significantly higher in the group of women residing in industrial areas compared to the group residing in rural areas. A clear diminishing temporal trend was observed compared to levels reported in previous studies. CONCLUSIONS: This study produced the largest dataset on serum concentrations of PCDDs, PCDFs and PCBs in women of childbearing age in Italy. RESULTS: confirmed that environmental and lifestyle factors may influence exposure to these contaminants and thereby the body burden. The observed marked temporal decline in body burden during three decades is in agreement with the general trend observed worldwide.

Biomonitoring and exposure assessment of people living near or working at an Italian waste incinerator: methodology of the SPoTT study.

Only few studies on the health effect of waste incinerators were focused on human biomonitoring (HBM). Our aim is to describe a protocol for assessing early variation of selected items in a population group living close to a waste incinerator in Turin, Italy. A cohort of 394 subjects was randomly selected, among residents near the incinerator and residents far from it. To achieve this sample size, 765 subjects were contacted. The cohort was monitored before the start-up of the plant and will be followed up 1 and 3 years after, with measurements of respiratory function, selected blood and urine parameters including 19 metals, 17 congeners of PCDDs/Fs, 12 congeners of DL-PCBs, 30 congeners of NDL-PCBs, 11 OH-PAHs, specific hormones (T3, T4, TSH, cortisol and ACTH) and common health parameters. The same protocol is applied for plant workers and breeders living near the plant. Individual exposure to urban pollution and waste incinerator fallout were assessed through the use of mathematical models. Information on individual habits was assessed using a specific questionnaire. SPoTT is the first Italian study that adopts a longitudinal design of appropriate statistical power to assess health impacts of waste incinerator plants' emission. The initial results comparing the baseline to the first follow-up are due at the end of 2016.

Persistent toxic substances in Mediterranean aquatic species.

Fish and fishery products may represent one of the main sources of dietary exposure to persistent toxic substances (PTSs) such as polychlorinated dibenzodioxins, dibenzofurans, and biphenyls; polybromodiphenyl ethers; organochlorine pesticides; perfluorooctanoic acid and perfluorooctane sulfonate; and inorganic mercury and methyl mercury. In this study, PTS contamination of Mediterranean fish and crustaceans caught in Italian coastal waters was investigated in order to increase the representativeness of the occurrence database for wild species. The objectives were to verify the suitability of regulatory limits for PTSs, identify background concentrations values, if any, and examine the possible sources of variability when assessing the chemical body burdens of aquatic species. Twelve wild species of commercial interest and two farmed fish species were chosen. Excluding methyl mercury, chemical concentrations found in wild species fell generally towards the low ends of the concentration ranges found in Europe according to EFSA database and were quite lower than the tolerable maximum levels established in the European Union; farmed fish always showed contamination levels quite lower than those detected in wild species. The data obtained for wild species seemed to confirm the absence of local sources of contamination in the chosen sampling areas; however, species contamination could exceed regulatory levels even in the absence of specific local sources of contamination as a result of the position in the food web and natural variability in species' lifestyle. A species-specific approach to the management of contamination in aquatic organisms is therefore suggested as an alternative to a general approach based only on contaminant body burden. A chemical-specific analysis performed according to organism position in the food chain strengthened the need to develop this approach.

Polychlorodibenzodioxin and -furan and dioxin-like polychlorobiphenyl distribution in tissues and dairy products of dairy buffaloes.

A pilot study was performed on three different dairy buffalo herds exposed without exposure control conditions to Polychlorodibenzodioxins and -furans (PCDDs, PCDFs) and Dioxin-like Polychlorobiphenyls (DL-PCBs). This study dealt with the relationship between the contamination levels (pg WHO2005-TE/g fat) in individual raw milk and those in edible tissues and with the contamination transfer from farm bulk milk to dairy products. On a cumulative basis, kidney (41, 67, and 21 pg WHO-TE/g fat) resulted more in equilibrium with milk (48, 42, and 20) than did muscle (25, 31, and 9), while liver showed a large bioaccumulation (221, 304, and 75), with marked differences of the congener profile. Mozzarella cheese contamination (23, 42, and 29 pg WHO-TE/g fat) was higher than that of bulk milk (20, 36, and 21), which suggested a role of casein precipitation in congener transfer. The above information could improve the effectiveness of risk management during a "dioxin" crisis.

PCDD, PCDF, AND DL-PCB analysis in food: performance evaluation of the high-resolution gas chromatography/low-resolution tandem mass spectrometry technique using consensus-based samples.

Due to safety concerns regarding dietary exposure to POPs, regulatory bodies are issuing detailed guidelines for testing for polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) ('dioxins') and dioxin-like (DL)-PCBs in foods of animal origin. Determination of the aforesaid chemicals at regulatory levels requires highly selective and sensitive testing techniques. The new generation of low-resolution mass spectrometers (triple quadrupoles) allows very low levels of quantification to be reached (in the order of tens of femtograms), thus suggesting a potential for their application in food and feed analysis. The performance of the low-resolution tandem mass spectrometry (LRMS/MS) approach with triple quadrupoles was assessed on a qualified set of food samples from proficiency tests (PTs) and defense analysis. Accuracy was tested comparing the results with data from high-resolution mass spectrometry (HRMS) and with consensus values from PTs. The cumulative TEQ results were characterized by deviations not exceeding 15% of PCDD + PCDF, DL-PCB, and PCDD + PCDF + DL-PCB (TEQ(TOT)) reference consensus values (sample TEQ(TOT) range, 2.29-25.1 pgWHO-TEQ(97)/g fat). Congener analytical variabilities did not influence significantly the WHO-TEQ(97) outcome of the corresponding sample. This preliminary performance evaluation highlights the potential of LRMS/MS as a routine technique for quantitative analysis of PCDDs, PCDFs, and DL-PCBs in food.

Persistent organic pollutants (POPs) in fish collected from the urban tract of the river Tiber in Rome (Italy).

European eel and chub samples were analyzed to determine the levels of non-dioxin-like polychlorobiphenyls (NDL-PCBs), polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs), dioxin-like PCBs (DL-PCBs), and brominated polybromodiphenyl ethers (PBDEs) in order to evaluate the extent of contamination of the river Tiber along the urban tract through the city of Rome (Italy). All samples presented detectable levels of the chemicals analyzed, and exhibited species-specific differences in terms of congener composition and total concentrations. On average the European eel presented the highest values. In this species the dioxin-like compound sums (WHO-TEQs) exceeded the pertinent maximum levels (MLs). Non-ortho PCBs constituted approximately 80% of WHO-TEQ toxicological potential whereas NDL-PCB and PBDE concentrations appeared to match values determined in other polluted aquatic ecosystems where non-point contamination sources were present. The contamination patterns determined in fish tissues seemed to reflect the impact of generic contamination source(s).

Artificial-turf playing fields: contents of metals, PAHs, PCBs, PCDDs and PCDFs, inhalation exposure to PAHs and related preliminary risk assessment.

The artificial-turf granulates made from recycled rubber waste are of health concern due the possible exposure of users to dangerous substances present in the rubber, and especially to PAHs. In this work, we determined the contents of PAHs, metals, non-dioxin-like PCBs (NDL-PCBs), PCDDs and PCDFs in granulates, and PAH concentrations in air during the use of the field. The purposes were to identify some potential chemical risks and to roughly assess the risk associated with inhalation exposure to PAHs. Rubber granulates were collected from 13 Italian fields and analysed for 25 metals and nine PAHs. One further granulate was analysed for NDL-PCBs, PCDDs, PCDFs and 13 PAHs. Air samples were collected on filter at two fields, using respectively a high volume static sampler close to the athletes and personal samplers worn by the athletes, and at background locations outside the fields. In the absence of specific quality standards, we evaluated the measured contents with respect to the Italian standards for soils to be reclaimed as green areas. Zn concentrations (1 to 19 g/kg) and BaP concentrations (0.02 to 11 mg/kg) in granulates largely exceeded the pertinent standards, up to two orders of magnitude. No association between the origin of the recycled rubber and the contents of PAHs and metals was observed. The sums of NDL-PCBs and WHO-TE PCDDs+PCDFs were, respectively, 0.18 and 0.67×10(-5) mg/kg. The increased BaP concentrations in air, due to the use of the field, varied approximately from <0.01 to 0.4 ng/m(3), the latter referring to worst-case conditions as to the release of particle-bound PAHs. Based on the 0.4 ng/m(3) concentration, an excess lifetime cancer risk of 1×10(-6) was calculated for an intense 30-year activity.

Polychlorodibenzodioxin and -furan (PCDD and PCDF) and dioxin-like polychlorobiphenyl (DL-PCB) congener levels in milk of grazing sheep as indicators of the environmental quality of rural areas.

An observational study was set up to evaluate how the quality of the environment may influence the levels of of PCDDs, PCDFs, and DL-PCBs in sheep's milk. Seven farms under natural and anthropogenic pressures were considered, along with an inventory of the surrounding regular and natural sources of emissions. Analysis by HRGC-HRMS revealed the highest cumulative levels (2.1 pg of WHO(1998)-TE/g fat) in one organic and one conventional farm, each close to a relevant bushfire. Their pattern was characterized by a noticeable contribution (24%) from mono-ortho-PCB congeners to the cumulative WHO-TE. For the other farms, close to potential anthropogenic sources, the levels recorded in milk ranged from 0.7 to 1.3 pg of WHO-TE/g fat. The health and reproductive indicators were in all herds within the physiological range. Results suggest the environmental quality in extensive farming system should be eligible as a food safety factor, also for organic productions.

Bioaccumulation of dioxin-like substances and selected brominated flame retardant congeners in the fat and livers of black pigs farmed within the Nebrodi Regional Park of Sicily.

An observational study was designed to assess the bioaccumulation of polychlorodibenzodioxins (PCDD) and polychlorodibenzofurans (PCDF), dioxin-like polychlorobiphenyls (DL-PCB), and 13 selected polybromodiphenylethers (PBDE) in autochthonous pigs reared in the Nebrodi Park of Sicily (Italy). Perirenal fat and liver samples were drawn from animals representative of three different outdoor farming systems and from wild pigs and then analyzed for the chemicals mentioned previously. The highest concentrations of PCDD + PCDF and DL-PCB were detected in the fat (0.45 and 0.35 pg World Health Organization toxicity equivalents [WHO-TE] per g of fat base [FB], respectively) and livers (12.7 and 3.28 pg WHO-TE per g FB) of the wild group, whereas the free-ranging group showed the lowest levels (0.05 and 0.03 pg WHO-TE per g FB in fat and 0.78 and 0.27 pg WHO-TE per g FB in livers). The sum of PBDE congeners was highest in wild pigs (0.52 ng/g FB in fat and 5.64 ng/g FB in livers) and lowest in the farmed group (0.14 ng/g FB in fat and 0.28 ng/g FB in livers). The contamination levels in fat and livers of outdoor pigs had mean concentration values lower than those levels reported for intensively indoor-farmed animals. In wild pigs, bioaccumulation was associated with their free grazing in areas characterized by bush fires. The results of this study aid to emphasize the quality of the environment as a factor to guarantee food safety in typical processed pig meat products, specifically from outdoor and extensive Nebrodi farming systems.

PCB, PCDD and PCDF contamination of food of animal origin as the effect of soil pollution and the cause of human exposure in Brescia.

In Brescia a PCB production plant polluted soil and forage of the surrounding fields and caused a significant contamination of meat and milk of the cattle fed with local forage. This in turn induced elevated blood levels of PCDDs, PCDFs and PCBs in the consumers. The contamination levels and profiles measured in the perirenal fat, in the liver and in the milk of the overall 28 contaminated bovines are reported. TEQ levels varied from 30 to 81 pg WHO(2005)-TEQ g(-1) (38-103 pg WHO(1997)-TEQ) for perirenal fat, from 107 to 138 pg WHO(2005)-TEQ g(-1) fat (128-168 pg WHO(1997)-TEQ) for liver and from 45 to 50 pg WHO(2005)-TEQg(-1) fat (56-65pg WHO(1997)-TEQ) for milk; all these values are roughly tenfold higher than the European limits. Non-ortho dioxin-like (dl)PCBs are by far the largest contributors to TEQ and PCDF contribution also largely prevail over PCDD's; both these features are also present in both the contaminated forages and in the serum of consumers of contaminated food. The indicator PCB levels are in the following ranges: 226-664 ng g(-1) for perirenal fat; 929-1822 ng g(-1) fat for liver; 183-477 ng g(-1) fat for milk; their level is about 100 times higher than the regional background. The liver samples displayed an overall TEQ several times higher than the perirenal fat from either the same animal or the same pool of animals; the increase in liver concentration was significantly higher for PCDD and PCDF congeners than for dlPCBs, and it was maximum for OCCD.

Normative and pre-normative aspects for the management of actual and perspective POPs in meat and meat products.

With the acronym POPs we intend a group of persistent organic pollutants framed within the Stockholm Convention [Stockholm Convention on Persistent Organic Convention (POPs) (2004). Available from http://www.pops.int/]. POPs are a subgroup of the wide family of the aforesaid chemicals present in the environment, that are primarily of industrial origin. According to their physical-chemical properties, bioaccumulative behaviour in lipid tissues, and possible toxicological effects, they represent a relevant and growing concern for human beings. Foodstuffs of animal origin represent the main source of exposure. Monitoring data from national residue plans report only few non-compliances with respect to regulatory limits. However, the estimated intake, as in the case of polychloro-p-dibenzodioxins (PCDD), polychlorodibenzofurans (PCDF) and dioxin-like polychlorobyphenils (DL-PCBs) may result close to the correspondent safety guidance value (i.e., the Tolerable Daily Intake), thus indicating the need to reduce the overall exposure. In animal productions, the sources of contamination may be the commercial feedingstuffs as well as the contact with contaminated soil and bedding materials and the overall quality of the environment where animal productions are carried out. In this light, a number of safety challenges are envisaged to produce meat, such as: (a) characterization of the environment, (b) identification of the animal-based risk factors, (c) model-based approaches, able to predict bioaccumulation, and (d) teaching and training of stockmen.

High concern chemicals in top layer sediments of the northern Adriatic seabed as markers of old waste dumpings.

The results are presented of a survey planned to assess the presence of high concern chemicals in sediments collected in a northern sector of the Adriatic sea neighboring the Venice lagoon. For the assessment, persistent marker chemicals were selected from the families of polycyclic aromatic hydrocarbons, polychlorobiphenyls, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and chlorinated pesticides. Based on the chemical-specific concentrations and PCDD+PCDF profiles determined in the sediments analyzed, dumping zones appear to have existed approximately 5-6km away from lagoon shoreline. Contamination levels exceed the quality criteria established by the pertinent Italian national regulation at many sampling sites, eventually reflecting ("fingerprinting") industrial activities once performed in the industrial settlement of Porto Marghera within the Venice lagoon. In coastal samples, concentration levels appear to be lower than those determined at offshore sampling sites.

A study on PCB, PCDD/PCDF industrial contamination in a mixed urban-agricultural area significantly affecting the food chain and the human exposure. Part I: soil and feed.

This study deals with a PCB, PCDD and PCDF contamination in Brescia, a city in the North-West of Italy, affecting an area with about 11000 inhabitants. The area is close to an industrial plant that produced, in total, some 31,000 ton of PCB. A relevant part of the polluted area is agricultural soil, where cattle were fed with polluted forage and farmers were consuming their own products, so that contamination led eventually to human exposure. Total levels of PCDD/Fs varied from 8 to 592 pgTE(WHO)/g for soil samples and when the dioxin-like PCBs (dl-PCBs) are included, the levels varied from 14.6 to 1033.7 pgTE(WHO)/g. In several cases, the legal limit was exceeded by more than one order of magnitude, with the highest contamination in some agricultural areas and in the surrounding zones. For the forage samples, total levels of PCDD/Fs varied from 0.29 to 2.04 pgTE(WHO)/g and, when dl-PCBs are included, this range increased from 2.04 to 4.75 pgTE(WHO)/g. PCB contamination of the forage through vapor condensation seemed to be relevant. The toxic contribution of dl-PCBs is always relevant and must be considered for risk management. The main component of the contamination source is probably a heavy PCB mixture, such as Aroclor 1262. The study dealt generally with the contamination transfer of PCBs, PCDDs and PCDFs from soil up to humans across the food chain. Results on soils and forages are shown, while measurements concerning the contamination of the animals fed with contaminated forage, and the exposure of the farmers (through human serum analyses), as compared to general population, will be reported in a dedicated paper.

Evaluation of emission toxicity of urban bus engines: compressed natural gas and comparison with liquid fuels.

Emissions from a spark-ignition (SI) heavy-duty (HD) urban bus engine with a three-way catalyst (TWC), fuelled with compressed natural gas (CNG), were chemically analyzed and tested for genotoxicity. The results were compared with those obtained in a previous study on an equivalent diesel engine, fuelled with diesel oil (D) and a blend of the same with 20% vegetable oil (B20). Experimental procedures were identical, so that emission levels of the CNG engine were exactly comparable to the ones of the diesel engine. The experimental design was focused on carcinogenic compounds and genotoxic activity of exhausts. The results obtained show that the SI CNG engine emissions, with respect to the diesel engine fuelled with D, were nearly 50 times lower for carcinogenic polycyclic aromatic hydrocarbons (PAHs), 20 times lower for formaldehyde, and more than 30 times lower for particulate matter (PM). A 20-30 fold reduction of genotoxic activity was estimated from tests performed. A very high reduction of nitrogen oxides (NO(X)) was also measured. The impact of diesel powered transport on urban air quality, and the potential benefits deriving from the use of CNG for public transport, are discussed.

Emission comparison of urban bus engine fueled with diesel oil and 'biodiesel' blend.

The chemical and toxicological characteristics of emissions from an urban bus engine fueled with diesel and biodiesel blend were studied. Exhaust gases were produced by a turbocharged EURO 2 heavy-duty diesel engine, operating in steady-state conditions on the European test 13 mode cycle (ECE R49). Regulated and unregulated pollutants, such as carcinogenic polycyclic aromatic hydrocarbons (PAHs) and nitrated derivatives (nitro-PAHs), carbonyl compounds and light aromatic hydrocarbons were quantified. Mutagenicity of the emissions was evaluated by the Salmonella typhimurium/mammalian microsome assay. The effect of the fuels under study on the size distribution of particulate matter (PM) was also evaluated. The use of biodiesel blend seems to result in small reductions of emissions of most of the aromatic and polyaromatic compounds; these differences, however, have no statistical significance at 95% confidence level. Formaldehyde, on the other hand, has a statistically significant increase of 18% with biodiesel blend. In vitro toxicological assays show an overall similar mutagenic potency and genotoxic profile for diesel and biodiesel blend emissions. The electron microscopy analysis indicates that PM for both fuels has the same chemical composition, morphology, shape and granulometric spectrum, with most of the particles in the range 0.06-0.3 microm.