Fourth European Symposium held in Stresa, Italy, September 23-25, 1986

Working Party 1: Analysis of Pollutants.- Summary by the Chairman.- Detection of gaseous nitric acid by OH (A?X) - fluorescence generated by ArF-laser irradiation.- Preparation of standard atmospheres of nitrogen acid compounds: the NO2 permeation tube.- Automated denuder systems.- A battery-powered light-weight ozone analyzer for use in the troposphere and stratosphere.- H2O2 in solid precipitation.- Detection of nitrated and oxygenated polyaromatic hydrocarbons (PAH) in suspended particulate matter sampled in urban areas and their relation with anthropogenic emission and photochemical smog formation.- Field intercomparison of sampling and analytical methods for SO2 and SO4 in ambient air.- Field measurements on the use of denuders for the evaluation of acid deposition.- Use of air - SO2 mixtures for intercomparison of SO2 monitors in the EEC.- Determination of polychlorinated dibenzo-P-dioxins and dibenzofurans in outdoor air.- Measurement of atmospheric nitrous and nitric acid by means of annular denuders.- Evaluation of analytical methods for the determination of degradation products of chlorinated hydrocarbons.- Sampling of aldehydes and carbonyl compounds in air and their determination by liquid chromatographic techniques.- The use of a filter pack for the monitoring organic and inorganic acid species in air.- IR-Tunable diode laser techniques for trace gas detection at PPBV level.- Measurement of airborne hydrocarbons by headspace-chromatography.- A study of atmospheric deposition chemistry in peninsular and insular Italy.- Chemistry of atmospheric depositions at L. TOGGIA (2160 m.a.s.l.), with emphasis on the sampling procedure.- Analysis of carbonyl compounds in the atmospheric liquid phase.- Working Party 2: Chemical and Photochemical Reactions;Mechanisms and Rates.- Summary by the Chairman.- Photo-oxidation of sulphur containing compounds.- Kinetic studies of oxidation reactions of sulphur compounds: reaction SO2 + OH in the presence of O2 and reaction 10 + DMS.- A comparison of models for the oxidation of acetylene at 300 K.- Rate constants for reaction of OH radicals with acetates and glycols in the gas phase.- OH-Dynamics during hydrocarbon oxidation in air.- Aqueous phase chemistry of biogenic sulphur compounds.- The contribution of hydrogen peroxide to atmospheric liquid phase chemistry.- A study of the HO2 + CH3CHO reaction in the photolysis of CH3CHO, and its consequences for atmospheric chemistry.- Laboratory studies of the nitrate radical.- Quelques aspects de la chimie des aldehydes dans la basse troposphere.- Kinetics of the formation of nitrous acid from the thermal reaction of nitrogen dioxide and water vapour.- FT-IR laboratory studies of kinetics of the NOx/O3 system of tropospheric interest.- OH-Initiated oxidation of P-xylene under atmospheric conditions.- Products and kinetics of the OH initiated oxidation of SO2, CH3SH, DMS, DMDS and DMSO.- Absolute rate constant for the reaction of OH with SO2 in the presence of water at atmospheric pressure.- The role of transition metal ions in atmospheric droplet chemistry.- Working Party 3: Aerosol Characterization and Particle Formation.- Summary by the Chairman.- Below and in cloud scavenging of particulates and gases.- Mesure d'aérosols dans la fôret des vosges.- Anionic composition in size-fractionated atmospheric aerosol.- Correlation analysis applied to a sulphate and nitrate aerosol measuring network in the Netherlands.- Cendres volantes industrielles et microspherules volcaniques: critères de distinction par microscopie analytique.-Radiolytic aerosols: their production and inhibition.- Chlorides in atmospheric aerosols.- Working Party 4: Pollutants Cycles.- Summary by the Chairman.- Emissions of biogenic sulfur compounds from various soils.- Dimethyl sulfide lifetime in the marine atmosphere.- Natural and anthropogenic hydrocarbons and halocarbons over the atlantic ocean: latitudinal distributions of mixing ratios and sources.- Characterization of cloud and rain water chemical composition.- Deposition measurements in Sweden.- Measurements of the dry deposition rates of some trace gas species.- Contribution of ammonia to the wet deposition of sulphur compounds.- Impact of saharan dust on the rain acidity in the mediterranean atmosphere.- Acid deposition in a snow field at 2500 m.a.s.l. in Switzerland.- Acidity measurements of snowfalls collected over the VOSGES in relation to air mass trajectories.- Nitrate and sulphate wet deposition in Europe.- Seasonal and daily variations of ozone, sulfur dioxide and nitrous gases and the photochemical production and reactions with other trace gases of the ozone.- A wet-only precipitation study in a mediterranean site, Patras, Greece.- Oxidant data collection in OECD-Europe 1985-87 (Oxidate): a cooperative project for rapid exchange of regional data on ozone, nitrogen dioxide and PAN.- Daily trends of photochemical oxidants and their precursors in a suburban forested area. A useful approach for evaluating the relative contributions of natural and anthropogenic hydrocarbons to the photochemical smog formation in rural areas in Italy.- Observations of nitrous acid at roof and street level during air pollution episodes in Gothenburg.- Speciation of ionic organolead compounds in the biosphere.- Preliminary results on fog deposition.- Determination, by PAHanalysis, of the age of air mass contamination in a area remote from sources of pollution.- Aircraft measurements of various sulfur compounds in a marine and continental environment.- Flux d'azote inorganique dissous d'origine atmosphérique en système littoral d'europe occidentale.- Meso-meteorological analysis of air pollution cycles in Spain.- Working Party 5: Transport and Modelling.- Summary by the Chairman.- Model calculations of long-term changes in atmospheric hydroxyl, hydrogen peroxide and ozone from changes in the emissions of nitrogen oxides and methane.- A mass balance of SO2 over Baden-Württemberg during the tulla experiment.- Mesoscale modelling of nitric acid generation in night-time moist atmosphere.- Long range modelling of the formation transport and deposition of photochemical oxidants and acidifying pollutants.- Analysis of an acid deposition episode and preparation of meteorological input data for an eulerian longrange transport and deposition model.- Physico-chemical properties of radiation fog in the Po Valley, Italy.- Air sampling flights at low altitudes along the border between the Federal Republic of Germany and its neighbours.- The oxidation of sulphur dioxide in the aqueous phase in plumes.- Monte-Carlo methods for simulating diffusion in the atmospheric boundary layer.- Modelling for langrangian turbulent dispersion of neutral and buoyant pollutants released in the atmospheric boundary layer.- A three-dimensional mathematical model of dispersion in turbulent shear flow.- The rapid rotation of the wind direction and sharp ozone peak features.- Local scale plume model for nitrogen oxides - comparison with measurements.- High PAN concentrations during non-summer periods: a study of two episodes in Creteil (Paris) - France.-Verification of the pollutant transport model 'MODIS' using EPRI plains site data from a tall stack.- Long-range transport of nitrogen and sulphur compounds.- Modélisation de la chimie d'un panache.- Echantillonnage et mesures sequentiels de pluies: conception d'un appareil équipé d'un automate programmable (SAPSEP).- List of Participants.- Index of Authors.