Effects of the flue gas treatment of incinerator plants on sub-micron particle concentrations at the stack.

The paper is focused on the emission of sub-micron particles from incinerator plants characterized by different treatment sections. In particular, measurement of particle number concentrations and distributions in different sampling points of the flue-gas treatment sections, and/or over several years, allowed to detect, for the very first time through in-field tests, the effect of the age of the fabric filter bags and of the SCR system on the emission of sub-micron particles. In fact, tests showed that the age of the fabric filter bags can affect the particle number concentrations at the stack: indeed, for older bags higher concentrations at the stack were measured likely due to the filter cleaning process. Concerning the effect of the SCR system, the natural gas combustion performed in the SCR system leads to an increase of sub-micron particle concentrations at the stack with respect to the values measured after the filtration section.

A novel approach to evaluate the lung cancer risk of airborne particles emitted in a city.

Air quality still represents a main threat to human health in cities. Even in developed countries, decades of air pollution control not yet allowed to reduce pollutant concentrations in urban areas adequately. Indeed, high airborne particle concentrations are measured in several European cities; this is a main issue since particles represent a carrier for carcinogenic compounds. Numerous researches measuring the exposure to the different aerosol metrics in urban areas were recently performed, nonetheless, few data on the lung cancer risk in such environments are available. In the present paper a novel approach to evaluate the lung cancer risk related to the airborne particles emitted by the different sources located in a city is proposed and applied to a pilot case-study (i.e. an Italian city). In particular, an existing lung cancer risk model was modified and applied to assess the particle-related lung cancer "emitted" by the different sources of the city using pollutant emission factors provided by accredited emission inventory databases. Therefore, the average toxicity of the particles emitted by the city (i.e. lung cancer slope factor) and the lung cancer risk globally emitted by the city, expressed as new cases of lung cancer, were evaluated. The proposed emission inventory also allowed to identify and localize the main contributors to the overall risk emitted in a city. As an example, for the city under investigation, the research revealed that the main contributor, amongst the sources considered, is the vehicular traffic which is characterized by a lower mass fraction of carcinogenic compounds but a much higher sub-micron particle emission with respect to the other sources.

Lung cancer risk assessment due to traffic-generated particles exposure in urban street canyons: A numerical modelling approach.

Combustion-generated nanoparticles are responsible for negative health effects due to their ability to penetrate in the lungs, carrying toxic compounds with them. In urban areas, the coexistence of nanoparticle sources and particular street-building configurations can lead to very high particle exposure levels. In the present paper, an innovative approach for the evaluation of lung cancer incidence in street canyon due to exposure to traffic-generated particles was proposed. To this end, the literature-available values of particulate matter, PAHs and heavy metals emitted from different kind of vehicles were used to calculate the Excess Lifetime Cancer Risk (ELCR) at the tailpipe. The estimated ELCR was then used as input data in a numerical CFD (Computational Fluid Dynamics) model that solves the mass, momentum, turbulence and species transport equations, in order to evaluate the cancer risk in every point of interest inside the street canyon. Thus, the influence of wind speed and street canyon geometry (H/W, height of building, H and width of the street, W) on the ELCR at street level was evaluated by means of a CFD simulation. It was found that the ELCR calculated on the leeward and windward sides of the street canyon at a breathable height of 1.5 m, for people exposed 15 min per day for 20 years, is equal to 1.5 × 10-5 and 4.8 × 10-6, respectively, for wind speed of 1 m/s and H/W equal to 1. The ELCR at street level results higher on the leeward side for aspect ratios equal to 1 and 3, while for aspect ratio equal to 2 it is higher on the windward side. In addition, the simulations showed that with the increasing of wind speed the ELCR becomes lower everywhere in the street canyon, due to the increased in dispersion.

Characterization of airborne particles emitted by an electrically heated tobacco smoking system.

Smoking activities were recognized as a main risk factor for population. Indeed, mainstream smoke aerosol is directly inhaled by smokers then delivering harmful compounds in the deepest regions of the lung. In order to reduce the potential risk of smoking, different nicotine delivery products have been recently developed. The latest device released is an electrically heated tobacco system (iQOS®, Philip Morris) which is able to warm the tobacco with no combustion. In the present paper a dimensional and volatility characterization of iQOS-generated particles was performed through particle number concentration and distribution measurements in the mainstream aerosol. The experimental analysis was carried out through a condensation particle counter, a fast mobility particle sizer and a thermo-dilution sampling system allowing aerosol samplings at different temperatures. Estimates of the particle surface area dose received by smokers were also carried out on the basis of measured data and typical smoking patterns. The particle number concentrations in the mainstream aerosols resulted lower than 1 × 108 part. cm-3 with particle number distribution modes of about 100 nm. Nonetheless, the volatility analysis showed the high amount of volatile fraction of iQOS-generated particles, indeed, samplings performed at 300 °C confirmed a significant particle shrinking phenomena (modes of about 20 nm). Anyway, the particle number concentration does not statistically decrease at higher sampling temperatures, then showing that a non-volatile fraction is always presents in the emitted particles. The dose received by smokers in terms of non-volatile amount of particle surface area was equal to 1-2 mm2 per puff, i.e. up to 4-fold larger than that received by electronic cigarette vapers.

Indoor exposure to particles emitted by biomass-burning heating systems and evaluation of dose and lung cancer risk received by population.

Homes represent a critical microenvironment in terms of air quality due to the proximity to main particle sources and the lack of proper ventilation systems. Biomass-fed heating systems are still extensively used worldwide, then likely emitting a significant amount of particles in indoor environments. Nonetheless, research on biomass emissions are limited to their effects on outdoor air quality then not properly investigating the emission in indoor environments. To this purpose, the present paper aims to evaluate the exposure to different airborne particle metrics (including both sub- and super-micron particles) and attached carcinogenic compounds in dwellings where three different heating systems were used: open fireplaces, closed fireplaces and pellet stoves. Measurements in terms of particle number, lung-deposited surface area, and PM fraction concentrations were measured during the biomass combustion activities, moreover, PM10 samples were collected and chemically analyzed to obtain mass fractions of carcinogenic compounds attached onto particles. Airborne particle doses received by people exposed in such environments were evaluated as well as their excess lung cancer risk. Most probable surface area extra-doses received by people exposed to open fireplaces on hourly basis (56 mm2 h-1) resulted one order of magnitude larger than those experienced for exposure to closed fireplaces and pellet stoves. Lifetime extra risk of Italian people exposed to the heating systems under investigation were larger than the acceptable lifetime risk (10-5): in particular, the risk due to the open fireplace (8.8 × 10-3) was non-negligible when compared to the overall lung cancer risk of typical Italian population.

The influence of lifestyle on airborne particle surface area doses received by different Western populations.

In the present study, the daily dose in terms of particle surface area received by citizens living in five cities in Western countries, characterized by different lifestyle, culture, climate and built-up environment, was evaluated and compared. For this purpose, the exposure to sub-micron particle concentration levels of the population living in Barcelona (Spain), Cassino (Italy), Guilford (United Kingdom), Lund (Sweden), and Brisbane (Australia) was measured through a direct exposure assessment approach. In particular, measurements of the exposure at a personal scale were performed by volunteers (15 per each population) that used a personal particle counter for different days in order to obtain exposure data in microenvironments/activities they resided/performed. Non-smoking volunteers performing non-industrial jobs were considered in the study. Particle concentration data allowed obtaining the exposure of the population living in each city. Such data were combined in a Monte Carlo method with the time activity pattern data characteristics of each population and inhalation rate to obtain the most probable daily dose in term of particle surface area as a function of the population gender, age, and nationality. The highest daily dose was estimated for citizens living in Cassino and Guilford (>1000 mm2), whereas the lowest value was recognized for Lund citizens (around 100 mm2). Indoor air quality, and in particular cooking and eating activities, was recognized as the main influencing factor in terms of exposure (and thus dose) of the population: then confirming that lifestyle (e.g. time spent in cooking activities) strongly affect the daily dose of the population. On the contrary, a minor or negligible contribution of the outdoor microenvironments was documented.

Particle-related exposure, dose and lung cancer risk of primary school children in two European countries.

Schools represent a critical microenvironment in terms of air quality due to the proximity to outdoor particle sources and the frequent lack of proper ventilation and filtering systems. Moreover, the population exposed in schools (i.e. children) represents a susceptible population due to their age. Air quality-based studies involving students' exposure at schools are still scarce and often limited to mass-based particle metrics and may thus underestimate the possible effect of sub-micron particles and particle toxicity. To this purpose, the present paper aims to evaluate the exposure to different airborne particle metrics (including both sub- and super-micron particles) and attached carcinogenic compounds. Measurements in terms of particle number, lung-deposited surface area, and PM fraction concentrations were measured inside and outside schools in Barcelona (Spain) and Cassino (Italy). Simultaneously, PM samples were collected and chemically analysed to obtain mass fractions of carcinogenic compounds. School time airborne particle doses received by students in classrooms were evaluated as well as their excess lung cancer risk due to a five-year primary school period. Median surface area dose received by students during school time in Barcelona and Cassino resulted equal to 110mm2 and 303mm2, respectively. The risk related to the five-year primary school period was estimated as about 2.9×10-5 and 1.4×10-4 for students of Barcelona and Cassino, respectively. The risk in Barcelona is slightly higher with respect to the maximum tolerable value (10-5, according to the U.S. Environmental Protection Agency), mainly due to toxic compounds on particles generated from anthropogenic emissions (mainly industry). On the other hand, the excess lung cancer risk in Cassino is cause of concern, being one order of magnitude higher than the above-mentioned threshold value due to the presence of biomass burning heating systems and winter thermal inversion that cause larger doses and great amount of toxic compounds on particles.

Do air quality targets really represent safe limits for lung cancer risk?

In order to estimate the lung cancer risk associated to airborne particles, exposure and risk-assessment studies ordinarily use particle mass concentration as dosimetry parameter. Consequently, the corresponding air quality targets are based on this metrics, neglecting the potential impact of ultrafine particles (UFPs) due to their negligible mass. The main purpose of this study was to evaluate the reliability of air quality targets in protecting Italian non-smoking people from lung cancer risk due to exposure to polycyclic aromatic hydrocarbons and some heavy metals associated with particle inhalation. A modified risk-assessment scheme was applied to estimate the cancer risk contribution from both sub-micron (mainly UFPs) and super-micron particles. We found a very high lung cancer risk related to the actual target levels due to the contribution of UFPs, in particular from indoor microenvironments. Therefore, as possible actions to reduce the lung cancer risk, we have hypothesized and tested three different scenarios: a) a reduction of the concentration of carcinogenic chemicals condensed onto particles in agreement with the current EU air pollution policy; b) the use of local ventilation systems to mitigate the exposure to cooking-generated particles; c) the improvement of the overall indoor air quality by considering a mechanical ventilation system instead of the widespread natural ventilation in order to increase the air exchange rates. Even with the simultaneous application of specific actions, performed with the best technologies available, the corresponding estimated lifetime lung cancer risk (ELCR) values for the Italian population for the entire life were equal to 1.25×10-4 and 1.23×10-4 for males and females, respectively, well higher with respect to the maximum tolerable lifetime cancer risk, 1×10-5.

Lung cancer risk of airborne particles for Italian population.

Airborne particles, including both ultrafine and supermicrometric particles, contain various carcinogens. Exposure and risk-assessment studies regularly use particle mass concentration as dosimetry parameter, therefore neglecting the potential impact of ultrafine particles due to their negligible mass compared to supermicrometric particles. The main purpose of this study was the characterization of lung cancer risk due to exposure to polycyclic aromatic hydrocarbons and some heavy metals associated with particle inhalation by Italian non-smoking people. A risk-assessment scheme, modified from an existing risk model, was applied to estimate the cancer risk contribution from both ultrafine and supermicrometric particles. Exposure assessment was carried out on the basis of particle number distributions measured in 25 smoke-free microenvironments in Italy. The predicted lung cancer risk was then compared to the cancer incidence rate in Italy to assess the number of lung cancer cases attributed to airborne particle inhalation, which represents one of the main causes of lung cancer, apart from smoking. Ultrafine particles are associated with a much higher risk than supermicrometric particles, and the modified risk-assessment scheme provided a more accurate estimate than the conventional scheme. Great attention has to be paid to indoor microenvironments and, in particular, to cooking and eating times, which represent the major contributors to lung cancer incidence in the Italian population. The modified risk assessment scheme can serve as a tool for assessing environmental quality, as well as setting up exposure standards for particulate matter.

Personal exposure to ultrafine particles: the influence of time-activity patterns.

Exposure to ultrafine particles (UFPs) is deemed to be a major risk affecting human health. Therefore, airborne particle studies were performed in the recent years to evaluate the most critical micro-environments, as well as identifying the main UFP sources. Nonetheless, in order to properly evaluate the UFP exposure, personal monitoring is required as the only way to relate particle exposure levels to the activities performed and micro-environments visited. To this purpose, in the present work, the results of experimental analysis aimed at showing the effect of the time-activity patterns on UFP personal exposure are reported. In particular, 24 non-smoking couples (12 during winter and summer time, respectively), comprised of a man who worked full-time and a woman who was a homemaker, were analyzed using personal particle counter and GPS monitors. Each couple was investigated for a 48-h period, during which they also filled out a diary reporting the daily activities performed. Time activity patterns, particle number concentration exposure and the related dose received by the participants, in terms of particle alveolar-deposited surface area, were measured. The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8 × 10(4) part. cm(-3); men 9.2 × 10(3) part. cm(-3); Winter: women 2.9 × 10(4) part. cm(-3); men 1.3 × 10(4) part. cm(-3)), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12 × 10(2) and 6.33 × 10(2) mm(2), respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in both winter and summer).

Influential parameters on particle concentration and size distribution in the mainstream of e-cigarettes.

Electronic cigarette-generated mainstream aerosols were characterized in terms of particle number concentrations and size distributions through a Condensation Particle Counter and a Fast Mobility Particle Sizer spectrometer, respectively. A thermodilution system was also used to properly sample and dilute the mainstream aerosol. Different types of electronic cigarettes, liquid flavors, liquid nicotine contents, as well as different puffing times were tested. Conventional tobacco cigarettes were also investigated. The total particle number concentration peak (for 2-s puff), averaged across the different electronic cigarette types and liquids, was measured equal to 4.39 ± 0.42 × 10(9) part. cm(-3), then comparable to the conventional cigarette one (3.14 ± 0.61 × 10(9) part. cm(-3)). Puffing times and nicotine contents were found to influence the particle concentration, whereas no significant differences were recognized in terms of flavors and types of cigarettes used. Particle number distribution modes of the electronic cigarette-generated aerosol were in the 120-165 nm range, then similar to the conventional cigarette one.

Indoor aerosols: from personal exposure to risk assessment.

Motivated by growing considerations of the scale, severity, and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state-of-the-art experimental techniques used for personal exposure assessment; (ii) compare exposure levels reported for domestic/school settings in different countries (excluding exposure to environmental tobacco smoke and particulate matter from biomass cooking in developing countries); (iii) assess the contribution of outdoor background vs indoor sources to personal exposure; and (iv) examine scientific understanding of the risks posed by personal exposure to indoor aerosols. Limited studies assessing integrated daily residential exposure to just one particle size fraction, ultrafine particles, show that the contribution of indoor sources ranged from 19% to 76%. This indicates a strong dependence on resident activities, source events and site specificity, and highlights the importance of indoor sources for total personal exposure. Further, it was assessed that 10-30% of the total burden of disease from particulate matter exposure was due to indoor-generated particles, signifying that indoor environments are likely to be a dominant environmental factor affecting human health. However, due to challenges associated with conducting epidemiological assessments, the role of indoor-generated particles has not been fully acknowledged, and improved exposure/risk assessment methods are still needed, together with a serious focus on exposure control.

Open tension-free Lichtenstein repair of inguinal hernia: use of fibrin glue versus sutures for mesh fixation.

PURPOSE: To investigate pain and other complications following inguinal hernioplasty performed by the Lichtenstein technique with mesh fixation by fibrin glue or sutures. METHODS: Five hundred and twenty patients were enrolled in this 12-month observational multicenter study and received either sutures or fibrin glue (Tissucol(®)/Tisseel(®)) based on the preference of the surgeon. Pain, numbness, discomfort, recurrence, and other complications were assessed postoperatively and at 1, 3, 6, and 12 months. Pain intensity was assessed by a visual analog scale (VAS; 0 [no pain] to 10 [worst pain]). RESULTS: One hundred and seventy-one patients received sutures and 349 received fibrin glue. During the early postoperative phase, 87.4% of patients in the fibrin glue group and 76.6% of patients in the sutures group were complication-free (P = 0.001). Patients who received fibrin glue were also less likely to experience hematoma/ecchymosis than those in the suture group (both P = 0.001). The mean pain score was significantly lower in the fibrin group than the sutures group (2.5 vs. 3.2, P < 0.001). At 1 month, significantly fewer patients in the fibrin glue group reported pain, numbness, and discomfort compared with patients in the sutures group (all P < 0.05). Fibrin glue patients also experienced less intense pain (0.6 vs. 1.2; P = 0.001). By 3 months, the between-group differences had disappeared, except for numbness, which was more prevalent in the sutures group. By 12 months, very few patients reported complications. CONCLUSIONS: Tissucol fibrin glue for mesh fixation in the Lichtenstein repair of inguinal hernia shows advantages over sutures, including lower incidence of complications such as pain, numbness, and discomfort, and should be considered as a first-line option for mesh fixation in hernioplasty.

Risk factors for coronary artery disease in healthy persons with hyperinsulinemia and normal glucose tolerance.

We studied the relation of serum insulin levels to plasma lipid levels and blood pressure in two groups drawn from among 247 healthy, normotensive nonobese subjects with normal glucose tolerance. One group of 32 subjects was defined as having hyperinsulinemia (serum insulin, greater than 2 SD above the mean) and then compared with 32 normoinsulinemic subjects (serum insulin within 1 SD of the mean) matched for age (mean, 39 years), sex (22 men and 10 women), and body-mass index (24.7). The two groups had similar patterns of smoking, drinking, and physical exercise. Plasma glucose levels after an oral glucose challenge were significantly higher (P less than 0.05) in the hyperinsulinemic group. In addition, the mean (+/- SEM) fasting plasma triglyceride levels in subjects with hyperinsulinemia were significantly higher (1.73 +/- 0.2 vs. 1.24 +/- 0.1 mmol per liter) and the plasma high-density lipoprotein cholesterol concentrations were lower (1.21 +/- 0.06 vs. 1.43 +/- 0.06 mmol per liter) than in subjects with normoinsulinemia. Both systolic (126 vs. 119 mm Hg; P less than 0.05) and diastolic (85 vs. 78 mm Hg; P less than 0.01) blood pressures were significantly elevated in the group with hyperinsulinemia. We conclude that healthy persons with hyperinsulinemia and normal glucose tolerance have an increase in risk factors for coronary artery disease, as compared with a well-matched group of healthy subjects with normal insulin levels.

Autoimmune hemolytic anemia and dermoid cyst of the mesentery. A case report.

An autoimmune hemolytic anemia has been detected in a patient suffering from a dermoid cyst of the mesentery. Early recognition of the teratoma is important, since only removal of the tumor is consistently curative. Investigations showing immunocompetent cells within the cyst's wall lend further support to the contention that the tumor tissue itself produces, for reasons yet unknown, antitumor autoantibodies that could cross-react with the patient's erythrocytes. The role of computerized tomography (CT) in the diagnosis of abdominal teratoma is emphasized, since CT has permitted visualization of the cystic structure of the tumor before the surgical removal of the mass.

Serum ferritin in beta-thalassaemia intermedia.

The iron status of 10 patients with beta-thalassaemia intermedia has been investigated in order to assess whether the liver iron overload could be constantly predicted through the patients' S-ferritin levels. Our data have shown that only when the iron overload is in the far advanced stages do the S-ferritin concentrations appear to be strongly raised, whilst in the early stages of the disease the levels fall to normal ranges with consequent underestimation of the expanding iron stores. Thus, in the early stages of the iron overload the liver iron burden of such patients is only reflected by both chemical and histochemical investigations performed on the liver biopsy specimens long before the rise in their S-ferritin levels.

L-glutaminase and L-asparaginase by extracorporeal route in acute lymphoblastic leukemia therapy.

Use of L-asparaginase by the extracorporeal route in the therapy of acute lymphoblastic leukemia (ALL) has been proposed. Results, however, are not so satisfactory as i.v. administration of this enzyme, because the levels of L-asparagine do not fall for a sufficient length of time due to the antagonistic action of the L-asparagine-synthetase. To avoid the L-asparagine rebound we have utilized, by extracorporeal route, L-glutaminase together with L-asparaginase, in order to reduce L-asparagine and L-glutamine levels. We have therefore performed a series of experiments in vitro and in vivo either using L-asparaginase alone or together with L-glutaminase. Results show that, contrary to what happens when L-asparaginase is used alone, L-asparagine levels decrease and remain low even after 24 hours from the treatment, when L-glutaminase is added to the system. Thus a lowering of L-glutamine levels, which seems to play an important role in the therapy of ALL, is obtained.