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The influence of 20 parameters on the measurement of light-vehicle emission factors on chassis dynamometer based on driving patterns, vehicle-related parameters, vehicle sampling, and laboratory-related parameters, was studied. The results were based on literature synthesis, ≈ 2700 specific tests with 183 vehicles, and the reprocessing of > 900 tests. Parameters that had a qualitative or quantitative influence on the emission measurements had a statistically significant influence. No statistically significant influence on emission measurement was found for some vehicle- and laboratory-related parameters. The influence of four parameters could be quantified, and quantitative correction factors were derived from the test data and were available to standardize emission measurements for the gearshift strategy, vehicle mileage, ambient air temperature, and ambient air humidity parameters. The mileage had no influence on the CO2 emission nor on the emissions of diesel vehicles, but increased CO, hydrocarbon, and NOx emissions of petrol cars. The hot emissions decreased with increasing temperature for petrol cars, but mainly for diesel ones. The influence of the ambient humidity existed only for NOx and for some vehicle classes. The best accuracy was encountered for CO2, for which the average coefficient of variation was around 5%. Diesel and petrol fuels strongly influenced the emissions, except for CO2.

This study uses an improved emission inventory model to assess the uncertainties in emissions of dioxins and furans associated with both knowledge on the exact technologies and processes used, and with the uncertainties of both activity data and emission factors. The annual total emissions for the year 2000 in 13 countries in central and eastern Europe can be estimated with 90% confidence within a range that is about a factor of 2-3 lower to a factor of 3-5 higher than a point value obtained from a more classical approach. It is also shown that the contribution of small residential sources and larger industrial installations and processes are of the same order of magnitude in these countries. It is argued that, despite these uncertainties, policy options can be evaluated and policy decisions on abatement of dioxin and furan emissions can be made. Dioxins and furans belong to the persistent organic pollutants (POPs), an important group of air pollutants that can have long-term effects on ecosystems and human health. Emission estimates for these pollutants all suffer from high uncertainties. This study shows that policy conclusions can still be derived despite these high uncertainties. © 2006 Elsevier Ltd. All rights reserved.

Background: Nano-specific inhalation exposure models could potentially be effective tools to assess and control worker exposure to nano-objects, and their aggregates and agglomerates (NOAA). However, due to the lack of reliable and consistent collected NOAA exposure data, the scientific basis for validation of the existing NOAA exposure models is missing or limited. The main objective of this study was to gain more insight into the effect of various determinants underlying the potential on the concentration of airborne NOAA close to the source with the purpose of providing a scientific basis for existing and future exposure inhalation models. Method: Four experimental studies were conducted to investigate the effect of 11 determinants of emission on the concentration airborne NOAA close to the source during dumping of ~100% nanopowders. Determinants under study were: nanomaterial, particle size, dump mass, height, rate, ventilation rate, mixing speed, containment, particle surface coating, moisture content of the powder, and receiving surface. The experiments were conducted in an experimental room (19.5 m3) with well-controlled environmental and ventilation conditions. Particle number concentration and size distribution were measured using real-time measurement devices. Results: Dumping of nanopowders resulted in a higher number concentration and larger particles than dumping their reference microsized powder (P < 0.05). Statistically significant more and larger particles were also found during dumping of SiO2 nanopowder compared to TiO2/Al2O3 nanopowders. Particle surface coating did not affect the number concentration but on average larger particles were found during dumping of coated nanopowders. An increase of the powder's moisture content resulted in less and smaller particles in the air. Furthermore, the results indicate that particle number concentration increases with increasing dump height, rate, and mass and decreases when ventilation is turned on. Discussion: These results give an indication of the direction and magnitude of the effect of the studied determinants on concentrations close to the source and provide a scientific basis for (further) development of existing and future NOAA inhalation exposure models. Chemicals/CAS: silicon dioxide, 10279-57-9, 14464-46-1, 14808-60-7, 15468-32-3, 60676-86-0, 7631-86-9; Air Pollutants, Occupational; Silicon Dioxide

Background: Long-term exposure to particulate matter air pollution has been associated with increased cardiopulmonary mortality in the USA. We aimed to assess the relation between traffic-related air pollution and mortality in participants of the Netherlands Cohort study on Diet and Cancer (NLCS), an ongoing study. Methods: We investigated a random sample of 5000 people from the full cohort of the NLCS study (age 55-69 years) from 1986 to 1994. Long-term exposure to traffic-related air pollutants (black smoke and nitrogen dioxide) was estimated for the 1986 home address. Exposure was characterised with the measured regional and urban background concentration and an indicator variable for living near major roads. The association between exposure to air pollution and (cause specific) mortality was assessed with Cox's proportional hazards models, with adjustment for potential confounders. Findings: 489 (11%) of 4492 people with data died during the follow-up period. Cardiopulmonary mortality was associated with living near a major road (relative risk 1.95, 95% CI 1.09-3.52) and, less consistently, with the estimated ambient background concentration (1.34, 0.68-2.64). The relative risk for living near a major road was 1.41 (0.94-2.12) for total deaths. Non-cardiopulmonary, non-lung cancer deaths were unrelated to air pollution (1.03, 0.54-1.96 for living near a major road). Interpretation: Long-term exposure to traffic-related air pollution may shorten life expectancy.

BACKGROUND: Negative effects of long-term exposure to particulate matter (PM) on lung function have been shown repeatedly. Spatial differences in the composition and toxicity of PM may explain differences in observed effect sizes between studies. METHODS: We conducted a multicenter study in 5 European birth cohorts - BAMSE (Sweden), GINIplus and LISAplus (Germany), MAAS (United Kingdom), and PIAMA (The Netherlands) - for which lung function measurements were available for study subjects at the age of 6 or 8 years. Individual annual average residential exposure to copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc within PM smaller than 2.5 μm (PM2.5) and smaller than 10 μm (PM10) was estimated using land-use regression models. Associations between air pollution and lung function were analyzed by linear regression within cohorts, adjusting for potential confounders, and then combined by random effects meta-analysis. RESULTS: We observed small reductions in forced expiratory volume in the first second, forced vital capacity, and peak expiratory flow related to exposure to most elemental pollutants, with the most substantial negative associations found for nickel and sulfur. PM10 nickel and PM10 sulfur were associated with decreases in forced expiratory volume in the first second of 1.6% (95% confidence interval = 0.4% to 2.7%) and 2.3% (-0.1% to 4.6%) per increase in exposure of 2 and 200 ng/m, respectively. Associations remained after adjusting for PM mass. However, associations with these elements were not evident in all cohorts, and heterogeneity of associations with exposure to various components was larger than for exposure to PM mass. CONCLUSIONS: Although we detected small adverse effects on lung function associated with annual average levels of some of the evaluated elements (particularly nickel and sulfur), lower lung function was more consistently associated with increased PM mass. Copyright © 2014 by Lippincott Williams & Wilkins. Chemicals/CAS: copper, 15158-11-9, 7440-50-8; iron, 14093-02-8, 53858-86-9, 7439-89-6; nickel, 7440-02-0; potassium, 7440-09-7; silicon, 7440-21-3; sulfur, 13981-57-2, 7704-34-9; vanadium, 7440-62-2; zinc, 7440-66-6, 14378-32-6 Funding Details: G0601361, MRC, Medical Research Council

In this study the effects of inhalatory exposure to coal fly ash on lung pathology and the immune system in rats were examined. Rats were exposed to 0, 10, 30, or 100 mg/m3 coal fly ash (6 h/day, 5 days/wk) for 4 wk, or to 0 and 100 mg/m3 for 1 wk, and for 1 wk followed by a recovery in clean air of 3 wk. A concentration-related increase in lung weight was found starting from 30 mg/m3 coal fly ash. After exposure to 100 mg/m3, a time-related deposition of free particles in the lungs was observed as well as a time-related number of coal fly ash particles phagocytized in alveolar macrophages. Histological examination revealed increased cellularity in alveolar septa, consisting mainly of mononuclear cell infiltrate, proliferated type II cells, and a slight fibrotic reaction. After a recovery period of 3 wk the histological picture was identical to that after 1 wk of exposure, indicating no significant recovery. No toxicological significant changes were found in the hematological, clinical chemistry, or urine parameters. Effects both on nonspecific defense mechanisms and on specific immune responses were noted. With regard to the immune function in the draining lymph nodes of the lung, a significantly increased number of both T and B lymphocytes was observed. The ratio of both cell types was not changed in either of the groups. In serum of exposed rats a significant increase of up to 150% of the immunoglobulin A (IgA) content was found. The number and phagocytic capacity of macrophages were significantly increased, while the killing of Listeria bacteria per cell ex vivo/in vitro remained unchanged. Natural killer (NK) activity in pulmonary cell suspensions was slightly stimulated in rats exposed for 4 wk to 10 and 30 mg/m3, whereas an exposure to 100 mg/m3 resulted in a slight decrease; however, both changes were not significant. In conclusion, the alterations in lung histopathology and immunity, observed in a dose and exposure time relation at concentrations up to and including 100 mg/m3 coal fly ash, may be considered an adverse response of the host to inhalation of particulate matter. Whether these observed alterations may effect the host resistance must be learned from infection studies.

Background: Most studies on the association between lung cancer and air pollution have investigated mortality. There have been few studies of lung cancer incidence. Methods: We used data from the ongoing Netherlands Cohort Study on Diet and Cancer for 114,378 subjects with follow-up from September 1986 to December 1997. Exposure to black smoke, nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter ≥2.5 μm (PM2.5) and traffic intensity variables (intensity on nearest road, intensity in a 100 m buffer, and an indicator variable for living close to a major road) were estimated at the home address. We conducted Cox proportional hazard analyses in the full cohort adjusting for age, sex, smoking status, and area-level socioeconomic status. We also carried out case-cohort analyses using more potential confounders on a subset of study participants for whom complete information from the baseline questionnaire had been processed. Results: Adjusted analyses included 1940 cases for the full cohort and 1295 cases for the case-cohort analysis. Relative risks (RRs) for the overall air pollution concentrations were slightly below unity, and for the traffic variables RRs were slightly elevated. Risk was elevated among people who never smoked cigarettes (40,114 participants; 252 cases), with RRs of 1.47 (95% confidence interval ≤ 1.01-2.16) for overall black smoke concentration, 1.11 (0.88-1.41) for traffic intensity on nearest road, and 1.55 (0.98-2.43) for living near a major road. Conclusions: We found evidence for an association of exposure to black smoke and traffic with lung cancer incidence in people who had never smoked. No associations were found for the full cohort, or for other categories of smoking. Copyright © 2008 by Lippincott Williams & Wilkins.

In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a tool in safety evaluation of complex mixtures. A "bottom-up" approach for chemosensory detection of mixtures has recently been presented. Other topics include a method for the safety evaluation of natural flavoring complexes, and an evaluation of the possible health effects of the simultaneous intake of food additives. Examples of issues related to mixtures of airborne chemicals are potential interaction of fine particles and gaseous pollutants in ambient air, nasal cancer associated with inhaled chemical mixtures, and the recommendation of a limit value for volatile organic compounds. Topics of a more strategic nature include studies concerning the public health effects of large airports, and the development of criteria for a harmonized classification of chemical mixtures. This overview illustrates that strategies to tackle the safety evaluation of combined exposures and complex mixtures as well as models facilitating the interpretation of findings in the context of risk assessment of mixtures have become increasingly important. It is true that exposure of humans to chemical mixtures is the rule rather than the exception, and therefore health risk assessments should focus on mixtures and not on single chemicals. It is also true, however, that humans have learned to cope with exposure to huge numbers of chemicals simultaneously (food, water, air, soil, and consumer products). Therefore, in view of limited resources for toxicological research, the focus in toxicology should be on priority mixtures - priority being determined by (estimated) health risk (= toxicity and exposure). Chemicals/CAS: Air Pollutants; Food Additives; Xenobiotics