Personal measurement of exposure to black carbon and ultrafine particles in schoolchildren from PARIS cohort (Paris, France).

This study aimed to measure in French children personal exposure concentrations of black carbon (BC) and ultrafine particles (UFP) and to quantify the contribution of different microenvironments (home, school, places of extracurricular activities, transport) to their total exposure. It was conducted on 96 9-year-old children from the PARIS birth cohort. BC and UFP were continuously measured by portable devices (microAeth® AE51 and DiSCmini® ) for a minimum of 24 hours, while participating families simultaneously filled in a space-time-activities-budget questionnaire. BC exposure concentration was higher during trips (principally metro/train and bus), while UFP exposure concentration was higher during indoor activities (mainly eating at restaurants) and in trips. The most important UFP peaks were measured at home, especially during cooking. Home and school together accounted for much of the total exposure, 83.8% for BC and 85.3% for UFP. The contribution of transport to total exposure was 12.4% for BC and 9.7% for UFP, while extracurricular activities were responsible for 3.8% and 5% of the total exposure to BC and UFP, respectively.

Characterisation of CIME, an experimental chamber for simulating interactions between materials of the cultural heritage and the environment.

An approach consisting in combining in situ and laboratory experiments is often favoured for investigating the mechanisms involved in the weathering of the materials of the cultural heritage. However, the realistic simulation in the laboratory of the environmental conditions ruling the interactions of atmospheric compounds with materials is a very complex task. The aim of this work is to characterise CIME, a new chamber specially built to simulate the interactions between materials of the cultural heritage and the environment. The originality of this instrument is that beside the usual climatic parameters (temperature, relative humidity, solar radiation) and gaseous pollutants, it also allows the controlled injection of different types of particulate matter such as terrigenous, marine and anthropogenic. Therefore, varied realistic atmospheric environments (marine or urban) can be easily simulated within CIME. In addition to the technical description of CIME, this paper shows the first results obtained by the impact of gaseous pollutants on non-durable glass, bronze and limestone. The first experiments for the deposition of different particles (calcite, clays, soot and halite) are also presented.

[Airway deposition of nanoparticles from second hand cigarette smoke]. / Rétention dans les voies aériennes des particules nanométriques de l'aérosol de la fumée de cigarette au cours du tabagisme passif.

INTRODUCTION: Second hand cigarette smoke consists predominantly of nanoparticles (with two dimensions less than 100 nanometres). The aim of this study was to examine the aerosol of cigarette smoke suspended in the air of a smoking room, its disappearance over the course of time, and its retention in the airways of passive smokers, as these processes remain poorly characterised. METHODS: A smoking machine produced cigarette smoke in a room. A low pressure electrostatic impactor with 13 plates, measured the size distribution and the concentration of the smallest particle sizes in the room air. Healthy adult volunteers (n=14) inhaled and exhaled this air through a nasal mask, allowing calculation of the retention of nanometric particles. RESULTS: The tobacco smoke aerosol was composed of 75% of nanometric particles. The half-life of these particles in the air was 18min. After 2h, 3% of the tobacco smoke particles remained suspended in the air. In passive smokers, the measured airway retention was on average 20%. CONCLUSION: This work shows that 75% of second hand cigarette smoke aerosol is made up of nanoparticles. When non-smokers inhale this passively, 20% of the particles are retained in their respiratory tract.

[Particle size in water pipe smoke]. / Tailles particulaires de la fumée de chicha.

INTRODUCTION: It is a popular perception that narghile (water pipe) smoking is less harmful to the lungs than cigarettes in both active and passive smokers. METHODS: Using a sinusoidal pump we simulated water pipe smoking in conditions close to users' habits. The particle sizes and concentrations in the smoke streams were measured with an electrical low pressure impactor (ELPI), sorting particle numbers and size into 12 classes ranging from 0.028 to 10 microm in diameter. RESULTS: Water pipe smoke contains microparticles and nanoparticles. The main inhaled smoke stream (C1) contains particles in a concentration of 3.55 x 10(6) ml(-1) with a median particle diameter (D50) of 0.34microm before bubbling through water. After bubbling, it retains 1.20 x 10(6) ml(-1) particles with a D50 of 0.27 mm, indicating that 2/3 of the particles are retained in the water, the smallest being trapped the less. Compared with C1, the D50 of the side stream smoke (C2) is smaller (0.11mm) while the D50 of the expired stream (C3) is similar (0.25mm). CONCLUSION: After bubbling, C1 particle sizes are similar to those measured in cigarette smoke but the volumes inhaled by a water pipe smoker are higher allowing prediction of greater deposition in the respiratory tract than with cigarette smoking.

[Particle size in the smoke produced by six different types of cigarette]. / Tailles particulaires de la fumée produite par six différents types de cigarettes.

INTRODUCTION: For several decades a more peripheral distribution of the broncho-pulmonary pathologies related to tobacco has been observed. METHODS: The aim of this study is to examine whether changes in the particle size of cigarette smoke as the result of new manufacturing technologies could play a part in the observed epidemiologic changes through a more distal disposition of smoke particles in the airways. Using a smoking machine and a low pressure electrostatic impactor we measured the particle size of the smoke from six different types of cigarette, representing old and new manufacturing techniques. The effect of a filter was assessed by a size analyser measuring the electrical mobility of the particles. RESULTS: The results show a difference in particle size between the primary smoke inhaled by the smoker, S1 (0.27 +/- 0.03 microm.) and the secondary smoke, S2 inhaled by passive smokers (0.09 +/- 0.01 microm). There is no difference in particle size between the 6 different types of cigarette. Filters dilute the smoke without altering particle size. CONCLUSION: The recent alterations in the distribution of tobacco related pathologies cannot be explained by changes in particle size in cigarette smoke. The explanation has to sought elsewhere.