Round-Robin Tests with Relocatable Coverslips Improve Asbestos Fibre Counting.

Asbestos fibre counting by phase-contrast microscope is subject to many sources of variation, including those dependent on the analyst. In this study, asbestos sample slides prepared with relocatable coverslips have been used for fibre counting among voluntary analysts to evaluate their proficiency. One slide of amosite and one of chrysotile were distributed to all the analysts, and three proficiency testing rounds were conducted for amosite and four for chrysotile. Each relocatable coverslip has a report in which are reported for each viewing field both the number of certified fibres (Verified Fibres) and a drawing representing the shape and position of the individual fibres. In the first round, the analysts were asked to report only the number of fibres counted in each of the predesignated fields of view. In the other rounds, subsequently developed, the analysts had to report the number and the position of the fibres for each field. The reported number of fibres and their position in each of the designed fields were evaluated against their respective verified fibres, to identify types of error. Discrepancies between reported fibres and verified fibres in each field of view have been used to evaluate the proficiency of the analysts. The discrepancies can be positive (D+) or negative (D-) depending on whether the analyst counts, for a specific field of view, more or less fibres compared to the verified fibres. The score is calculated using the following equation: Score = (1 - ∑D+ + ∑│D-│/VF) × 100. An analyst obtaining a score of ≥60, which corresponds to (∑D+ + ∑│D-│)/VF ≤ 0.40, is proficient. The number of laboratories that participating in this study varied from 13 to 17 depending on the rounds. For amosite fibre counts, the results were generally good compared to a proficiency score of 60. The major error made by analysts was the counting of fibres shorter than 5 µm, where this error was of 62% of extra fibres and accounted for 8% over-estimation of amosite fibres. For chrysotile, a score of ≥50 has been used to consider an analyst as proficient. The results of chrysotile fibres showed that in the first round all analysts counted less than fifty per cent of the verified fibres. In the second round 10 analysts out of 13 reached a score of ≥50, 8 of 16 in the third and 10 of 12 in the fourth. For chrysotile fibres, the error relating to the counting of fibres shorter than 5 µm was of 56% of extra fibres, but the error that most influenced the results was the number of oversight-missing fibres. This type of error accounted for 97% of the missing fibres and for the 29% under-estimation of the chrysotile fibres. For amosite fibre counting, results of this study show an improvement of the analyst's performance. For the chrysotile fibre count, although there is a significant improvement in the comparison between some rounds, this is not continuous over time.

Saharan dust and associations between particulate matter and daily mortality in Rome, Italy.

BACKGROUND: Outbreaks of Saharan-Sahel dust over Euro-Mediterranean areas frequently induce exceedances of the Europen Union's 24-hr standard of 50 µg/m3 for particulate matter (PM) with aerodynamic diameter ≤ than 10 µm (PM10). OBJECTIVES: We evaluated the effect of Saharan dust on the association between different PM fractions and daily mortality in Rome, Italy. METHODS: In a study of 80,423 adult residents who died in Rome between 2001 and 2004, we performed a time-series analysis to explore the effects of PM2.5, PM2.5-10, and PM10 on natural, cardiac, cerebrovascular, and respiratory mortality. We defined Saharan dust days by combining light detection and ranging (LIDAR) observations and analyses from operational models. We tested a Saharan dust-PM interaction term to evaluate the hypothesis that the effects of PM, especially coarse PM (PM2.5-10), on mortality would be enhanced on dust days. RESULTS: Interquartile range increases in PM2.5-10 (10.8 µg/m3) and PM10 (19.8 µg/m3) were associated with increased mortality due to natural, cardiac, cerebrovascular, and respiratory causes, with estimated effects ranging from 2.64% to 12.65% [95% confidence interval (CI), 1.18-25.42%] for the association between PM2.5-10 and respiratory mortality (0- to 5-day lag). Associations of PM2.5-10 with cardiac mortality were stronger on Saharan dust days (9.73%; 95% CI, 4.25-15.49%) than on dust-free days (0.86%; 95% CI, -2.47% to 4.31%; p = 0.005). Saharan dust days also modified associations between PM10 and cardiac mortality (9.55% increase; 95% CI, 3.81-15.61%; vs. dust-free days: 2.09%; 95% CI, -0.76% to 5.02%; p = 0.02). CONCLUSIONS: We found evidence of effects of PM2.5-10 and PM10 on natural and cause-specific mortality, with stronger estimated effects on cardiac mortality during Saharan dust outbreaks. Toxicological and biological effects of particles from desert sources need to be further investigated and taken into account in air quality standards.

Evaluation of the temporal variation of air quality in Rome, Italy, from 1999 to 2008.

The main objective of this study was to asses the temporal variation (1999 trough 2008) of air quality in Rome, focusing on airborne concentration of selected pollutants (PM10 and PM2.5 mass concentration and particle number concentration, PNC, carbon monoxide, CO, nitrogen oxides, NO and NO2) used for health effects assessment in epidemiological analyses. Time series analysis using Seasonal Kendall test has been applied. A statistically significant decreasing trend was found for primary gaseous pollutants and total particle number concentrations. Moreover a decreasing trend was assessed for PM10, PM2.5 and NO2 measured at traffic oriented sites even if the estimated reduction was lower compared with NO, CO and PNC. The urban background PM10 and NO2 concentrations seem to be practically unchanged since 1999 as no statistically significant trends were found. All the pollutants show higher slope of the estimated trend line at traffic oriented sites compared with those observed at the urban background. Thus a reduction of the intra-city concentration variability throughout the years occurred.

Impact of fine and ultrafine particles on emergency hospital admissions for cardiac and respiratory diseases.

BACKGROUND: Little is known about the short-term effects of ultrafine particles. METHODS: We evaluated the effect of particulate matter with an aerodynamic diameter or=35 years hospitalized for acute coronary syndrome, heart failure, lower respiratory tract infections, and chronic obstructive pulmonary disease (COPD). Information was available for factors indicating vulnerability, such as age and previous admissions for COPD. Particulate matter data were collected daily at one central fixed monitor. A case-crossover analysis was performed using a time-stratified approach. We estimated percent increases in risk per 14 microg/m PM10, per 10 microg/m PM2.5, and per 9392 particles/mL. RESULTS: An immediate impact (lag 0) of PM2.5 on hospitalizations for acute coronary syndrome (2.3% [95% confidence interval = 0.5% to 4.2%]) and heart failure (2.4% [0.3% to 4.5%]) was found, whereas the effect on lower respiratory tract infections (2.8% [0.5% to 5.2%]) was delayed (lag 2). Particle number concentration showed an association only with admissions for heart failure (lag 0-5; 2.4% [0.2% to 4.7%]) and COPD (lag 0; 1.6% [0.0% to 3.2%]). The effects were generally stronger in the elderly and during winter. There was no clear effect modification with previous COPD. CONCLUSIONS: We found sizeable acute health effects of fine and ultrafine particles. Although differential reliability in exposure assessment, in particular of ultrafine particles, precludes a firm conclusion, the study indicates that particulate matter of different sizes tends to have diverse outcomes, with dissimilar latency between exposure and health response.

Exposure to fine and ultrafine particles from secondhand smoke in public places before and after the smoking ban, Italy 2005.

BACKGROUND: A smoking ban in all indoor public places was enforced in Italy on 10 January 2005. METHODS: We compared indoor air quality before and after the smoking ban by monitoring the indoor concentrations of fine (<2.5 microm diameter, PM2.5) and ultrafine particulate matter (<0.1 microm diameter, UFP). PM2.5 and ultrafine particles were measured in 40 public places (14 bars, six fast food restaurants, eight restaurants, six game rooms, six pubs) in Rome, before and after the introduction of the law banning smoking (after 3 and 12 months). Measurements were taken using real time particle monitors (DustTRAK Mod. 8520 TSI; Ultra-fine Particles Counter-TRAK Model 8525 TSI). The PM2.5 data were scaled using a correction equation derived from a comparison with the reference method (gravimetric measurement). The study was completed by measuring urinary cotinine, and pre-law and post-law enforcement among non-smoking employees at these establishments RESULTS: In the post-law period, PM2.5 decreased significantly from a mean concentration of 119.3 microg/m3 to 38.2 microg/m3 after 3 months (p<0.005), and then to 43.3 microg/m3 a year later (p<0.01). The UFP concentrations also decreased significantly from 76,956 particles/cm3 to 38,079 particles/cm3 (p<0.0001) and then to 51,692 particles/cm3 (p<0.01). Similarly, the concentration of urinary cotinine among non-smoking workers decreased from 17.8 ng/ml to 5.5 ng/ml (p<0.0001) and then to 3.7 ng/ml (p<0.0001). CONCLUSION: The application of the smoking ban led to a considerable reduction in the exposure to indoor fine and ultrafine particles in hospitality venues, confirmed by a contemporaneous reduction of urinary cotinine.

Two-years of fine and ultrafine particles measurements in Rome, Italy.

Long-term aerosol measurements have been conducted at two sites in Rome, Italy, April 2001 through March 2003, in a traffic-oriented site, and at an urban background site, close to the city center. The main objective was to establish validated and consistent data sets of particle number concentrations (PNC) in Rome to be used for epidemiological analyses of cardiovascular health effects. Particle number concentrations were measured by a condensation particle counter (CPC 3022A, TSI). Other pollutants (PM10, PM2.5, CO, NO2, NO, NOx, O3) were simultaneously measured at the traffic-oriented site. During the study period, the mean (standard deviation) 24-h PNC values were 4.69 x 10(4) (1.99 x 10(4)) cm(-3) and 2.46 x 10(4) (1.10 x 10(4)) cm(-3), respectively, at the traffic-oriented site and at the urban background site. Mean (standard deviation) 24-h mass concentration of PM2.5 was 23.1 (11.9) microg m(-3), while for PM10 it was 41.3 (17.9) microg m(-3). Higher values for all the pollutants, except ozone, were recorded during the winter period in comparison with the summer period, and a higher variability of the results was also observed during cold months. The comparison between the daily PNC measured at the two sites showed a good correlation (r = .74). CO (r = .77), NO (r = .82), and NOx (r = .83) were all highly correlated with PNC (simultaneous obs. number 576). The diurnal and seasonal pattern of PNC can be attributed to the combined effect of motor vehicle emissions and meteorological conditions.

Air pollution and lung function among susceptible adult subjects: a panel study.

BACKGROUND: Adverse health effects at relatively low levels of ambient air pollution have consistently been reported in the last years. We conducted a time-series panel study of subjects with chronic obstructive pulmonary disease (COPD), asthma, and ischemic heart disease (IHD) to evaluate whether daily levels of air pollutants have a measurable impact on the lung function of adult subjects with pre-existing lung or heart diseases. METHODS: Twenty-nine patients with COPD, asthma, or IHD underwent repeated lung function tests by supervised spirometry in two one-month surveys. Daily samples of coarse (PM10-2.5) and fine (PM2.5) particulate matter were collected by means of dichotomous samplers, and the dust was gravimetrically analyzed. The particulate content of selected metals (cadmium, chrome, iron, nickel, lead, platinum, vanadium, and zinc) was determined by atomic absorption spectrometry. Ambient concentrations of nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and sulphur dioxide (SO2) were obtained from the regional air-quality monitoring network. The relationships between concentrations of air pollutants and lung function parameters were analyzed by generalized estimating equations (GEE) for panel data. RESULTS: Decrements in lung function indices (FVC and/or FEV1) associated with increasing concentrations of PM2.5, NO2 and some metals (especially zinc and iron) were observed in COPD cases. Among the asthmatics, NO2 was associated with a decrease in FEV1. No association between average ambient concentrations of any air pollutant and lung function was observed among IHD cases. CONCLUSION: This study suggests that the short-term negative impact of exposure to air pollutants on respiratory volume and flow is limited to individuals with already impaired respiratory function. The fine fraction of ambient PM seems responsible for the observed effects among COPD cases, with zinc and iron having a potential role via oxidative stress. The respiratory function of the relatively young and mild asthmatics included in this study seems to worsen when ambient levels of NO2 increase.

Aerosol particle number concentration measurements in five European cities using TSI-3022 condensation particle counter over a three-year period during health effects of air pollution on susceptible subpopulations.

In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm(-3) and 20,000 cm(-3), whereas the summer min is approximately 5000-6000 cm(-3). In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4-10. The winter maximum in both Rome and Barcelona is close to 100,000 cm(-3), whereas the summer minimum is > 10,000 cm(-3). During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.

[Air pollution and fatal and non fatal coronary events in Rome]. / Inquinamento atmosferico ed eventi coronarici fatali e non fatali a Roma.

OBJECTIVE: To examine the relationship between air pollution and coronary events in Rome in the period 1998-2000, considering both out-of-hospital deaths and hospitalisations. DESIGN: Time-series of daily counts of out-of-hospital deaths and hospitalised events, implementation of Generalised Additive Models. SETTING: The air pollutants taken into account were PNC (Particle Number Concentration--a measure of ultrafine particles), PM10, CO, NO2, SO2 and O3. The association was studied with respect to either single days or the cumulative effect on more consecutive days; furthermore, effect modification by age was tested (for the age groups 0-64, 65-74 and 75+). PARTICIPANTS: People resident of Rome and died/hospitalised for coronary causes into the city in the period 1998-2000. MAIN OUTCOME MEASURE: Association between pollutants and out-of-hospital deaths/hospitalised events. Distinction between fatal events (out-of-hospital deaths + hospitalisations with death within 28 days of admission) and non fatal events (hospitalisations with survival longer than 28 days). RESULTS: Significant association between PNC, PM10, and CO with out-of-hospital deaths, smaller effect on hospitalised events. For a variation of PNC of 28000 particles per cm3 (interquartile range of the distribution) the increase in the risk of out-of-hospital coronary death at lag 0 was 8.1%; for hospital admissions, the risk increased by 4%. The association was stronger in subjects older than 65, and was more evident for total fatal events than for non-fatal hospitalisations. CONCLUSION: The study showed increased risks of coronary events associated with air pollution in Rome: ultrafine particles, directly generated by vehicular traffic, are the environmental indicator which best characterizes the health risk.

[Pleural mesothelioma and environmental exposure to mineral fibres: the case of a rural area in the Basilicata region, Italy]. / Mesotelioma pleurico ed esposizione ambientale a fibre minerali: il caso di un'area rurale in Basilicata.

The main aspects of the sites characterized by environmental exposure to mineral asbestiform fibres are described. Several adverse health effects including high incidence of pleural mesothelioma are reported. The average concentration of airborne fibres is generally low but it rises significantly in association with mechanical disturb of materials with fibres. Multiple sources of exposure have been identified, fibres can be found in the soil and in many materials locally used, mainly in buildings. Three mesothelioma cases were observed in a small rural area of the Basilicata region (Italy). Two of them had a possible occupational exposure to asbestos, the third had a proved environmental exposure to tremolite. This fibre, found in the area, is the same observed in two of the three biological samples analysed.

[Airborne particulate matter: definitions, health effects, measurement and summary of environmental studies in Rome]. / Materiale particellare aerodisperso: definizioni, effetti sanitari, misura e sintesi delle indagini ambientali effettuate a Roma.

Epidemiological studies conducted in different countries have reported associations between increases in PM concentration and increases in morbidity and mortality, particularly among those people with respiratory or cardiovascular diseases. However, there are still important unanswered questions concerning potential biologic mechanisms of PM effects, the identification of the factors responsible of the adverse health effects (size and or chemical composition), the groups of people that may be particularly sensitive to the effects of PM. The most recent hypotheses indicate that ultrafine particles (UF) (< 0.1 microm) and transition metals (like Fe) may play an important role in the induction of toxic effects. Results obtained during last years in some sites located in the city center of Rome, showed mean annual levels of PM10 and PM2.5, that were often higher than 40 microg/m3, with peak values during winter months. UF particles concentrations showed similar seasonal trends, and daily trend correlated with increasing traffic fluxes, with peak levels of 10(5) p/cm3.

[Particulate matter measurements PM2.5 and PM10 in Rome: comparison indoor/outdoor]. / Misure di materiale particellare PM10 e PM2.5 a Roma: confronti indoor/outdoor.

The concentration of airborne particulate matter (PM2.5 and PM10) was assessed over 12 months (1999-2000) both outdoor and indoor (workplaces and homes without major PM sources) through a manual gravimetric method. Mean concentration values outdoors were moderately lower than indoor concentrations in summer, but higher in winter. The correlations between outdoor and indoor values are statistically significant, especially for PM2.5 in winter. The position of indoor sites with respect to street level was immaterial as far as mean values is concerned, whilst maximum values presented some differences accordingly. Day-to-day variability was higher outside than inside, especially in winter. The PM2.5/PM10 ratio was higher indoors, probably owing to the higher sedimentation speed of the coarse fraction.

[Occurrence of metals in various size fractions of particulate matter]. / Contenuto di metalli nelle varie frazioni dimensionali di materiale particellare.

Size distributions of trace metals of specific health concern (Pb, Cd, Cr, Ni, Cd, V, Zn and Fe) in the fine (PM2.5) and coarse (PM2.5-10) fractions of suspended particulate matter were evaluated. Samples were collected through a year in three sites (traffic oriented and urban background in the urban area of Rome, and remote, in the Regional Park of Simbruini Mountains). Mean concentrations never exceeded the values recommended by WHO and EU. During winter season, levels of Cr, Cd, Pb and Zn resulted higher than in summer, in both fine and coarse fractions. The series of Pb, Cd, and V concentrations clearly showed a predominant fine-particle distribution, whereas Cr, Mn and Ni were more equally distributed between the coarse and fine fractions. Fe prevailed in the coarse mode at the urban sites. At the urban sites mean concentrations of the different metals were from 4 to 22 times higher than at the remote site. For various metals the distribution mode, as well as the seasonal trends of the concentrations, showed significant differences between urban and remote site. In busy and densely populated urban areas, without relevant industrial emissions, anthropogenic sources of metallic species seem still to give a contribution to air pollution, though a trend downwards, compared to previous surveys, was observed, particularly for Pb.

[Airborne fine particles pollution and health risks estimates]. / Inquinamento da particelle fini aerodisperse e stime di rischio sanitario.

In this paper the results of the analyses of health risks associated with PM10 and PM2.5 are discussed, which have been made by the WHO and by a recent Italian multicentric epidemiological study in 8 cities. The distribution of PM10 and PM2.5 levels in the various cities are also considered. WHO estimates of short-term relative risk of daily mortality were 1.0074 and 1.015, by 10 microg/m3 increase respectively of PM10 and of PM2.5. Long-term risk estimates of mortality for the same increase of PM10 and PM2.5 were respectively 1.10 and 1.14, whereas more recent evaluations have indicated a value of 1.07 for PM2.5. The Italian meta-analysis study was concentrated on short-term effects associated to PM10. The effect estimate on mortality was an increase of 1.17%. The short-term effects indicated by the Italian study appeared greater than those estimated by WHO, but the confidence intervals (0.44%-2.06%) included the value of 0.74%. The hypothesis of a greater risk in Italy for the same increase of PM10 deserves further examination. The available mean concentration levels of PM10 in Italy showed an acceptable agreement, even if they were produced by different bodies. Mean yearly concentration of PM10 in the major Italian cities resulted about 50 microg/m3, range 30 microg/m3 to less than 70 microg/m3 since the first '90 up to 2001. Very few data are available on PM2.5, with the exception of Rome where mean annual levels resulted near 28 microg/m3, with 24 h averages ranging from 5 to 101 microg/m3.

[Air pollution and cardiac and respiratory function in three groups of patients]. / Inquinamento atmosferico e funzionalità cardiaca e respiratoria in tre gruppi di pazienti.

The association between exposure to urban air pollution and cardiac or respiratory impairments in susceptible subjects was evaluated in a panel study including 11 patients with chronic obstructive pulmonary disease (COPD), 7 with ischemic heart disease (IHD), and 11 asthmatics resident in Rome (Italy). Patients underwent repeated 24 h Holter EKG monitoring, 12 h pulse oximetry at night and spirometry examinations during 1999 summer and winter. Multiple linear regression models for repeated individual measures (fixed-effect) were used to analyse the relationship between average daily concentrations of pollutants (PM10-2.5, PM2.5 NO2 and O3) and outcome variables, controlling for meteorological conditions, survey period, and week-ends. In the BPCO panel, increasing ambient PM2.5 levels were associated with increased heart rate and decreased respiratory function. In the asthmatic panel, inverse associations between pulmonary function and both NO2 and PM10-2.5 concentrations were observed, as well as direct association between ambient NO2 concentrations and NO in exhaled breath. In the IHD panel an increase of hearth rate variability associated with increasing concentration of PM2.5 was observed.