The focus in the present study is the spatialvariation of anthropogenic volatile organic carbon compounds (VOC), mainly benzene and toluene, in parks and their built-up surroundings. Case studies were located in two large Scandinavian cities and measurements were made two meters aboveground level in maximum traffic periods. The results showedlarge variations in time and space but despite high pollutionlevels in the streets the air in parks and non-traffickedbuilt-up areas are substantially cleaner. The pollutantconcentration inside a large park decreased to a low level(i.e. 1/3 to 1/9 the concentration at the source) in a shortdistance (<40 m). An analysis showed that measured VOC wasassociated with fresh emissions, suggesting that the localtraffic intensity was the main governing parameter. It is,however, obvious that the spatial pattern of pollution is theresult of a combination of many different factors and variablesincluding traffic intensity, weather, local climate, land useand the character of park border.

Twenty-eight volatile organic compounds have been measured in a 3-month monitoring campaign. The sampling point is locatedin the urban centre of La Coruña, a medium-size town in theNorthwest of Spain. Only a petrol refinery can be consideredas an important point VOCs source in its surrounding area.The municipal landfill collapsed in September 1996, and rebuilding works caused strong odour episodes at the urbancentre. We tried to check how this problem affected urban airquality. Samples were taken with Tenax-TA tubes and analysedby thermal desorption-GC-MS. From the results obtained, traffic emissions were recognised as the main VOCs source inthe sampling zone. On November 9th a contaminationepisode took place. Aromatic and aliphatic compounds levelswere probably affected by emissions from fuel treatmentprocesses in a nearby petrol refinery. No influence onquantified VOCs concentrations from the remaking landfillworks was observed. Several compounds (organosulphurs, estersand alcohols) were recognised as the cause of odour problems.

This research was done on the effectof high concentration of negative ions in the air onchlorophyll contents and photosynthetic efficiency in leavesof Zea mays L. In vivo reflectance and chlorophyllfluorescence were measured in intact maize leaves before andafter exposing to the high concentration of negative ions inthe air. Reflectance, yield of chlorophyll fluorescence, redshift in chlorophyll fluorescence and blue shift inreflectance are observed in exposed species. These resultsindicate that high concentrations of negative ions inair cause significant change in: a) chlorophyll content andb) photosynthetic efficiency.

Corrosion products have been takenfrom 130 copper or bronze outdoor objects all overEurope. Their chemical composition and crystalsymmetry have been determined by means of scanning electron microscopy (SEM/EDS) and X-ray powderdiffraction. Data on location, sampling, objectcharacteristics, general environment and air pollutionlevel; type, colour and chemical composition of thecorrosion layers have been obtained and evaluated by multivariate statistical analysis. The resultsverify that the highest air pollution levels are usually associated with the occurrence of thick,black or dark grey corrosion layers on copper orbronze objects, preferentially containing soot, ironoxide hydroxides, and antlerite,Cu₃(SO₄)(OH)₄. Pale green corrosionusually contains brochantite,Cu₄(SO₄)(OH)₆, and is rather associatedwith less polluted areas. Atacamite, a copper hydroxide chloride with the chemical formula Cu₂Cl(OH)₃, is preferentially observed in coastal regions.In addition, sulphur isotope analyses have beenperformed on eleven corrosion samples from citycenters. The δ³⁴S values are typically inthe region from +4 to +6‰ relative to the sulphurisotope standard CDT (Canyon Diablo Troilite) with amean value of 4.7±1.2 (1σ), therebyindicating that the sulphur in the corrosion layers,in the form of brochantite or antlerite, mainlyoriginates from a similar source despite geographicvariation, most likely sulphur contained in air pollutants.

Air monitoring stations were set up at 2 sites in the southern hemisphere — Moody Brook, Falkland Islands (51° 25′ S, 57° 56′W) and Halley, Research Station, Antarctica (75° 35′ S, 26° 30′ W). PCBs were monitored at the stations throughout 1999. Highest concentrations were observed when temperatures were greater. In general, concentrations were greater at Moody Brook than at Halley, although the difference in concentrations between sites was less for more chlorinated congeners. Air concentrations at both sites were compared with samples collected nearby over-water. Over water air concentrations were found to be greater than over land air concentrations. Concentrations were also compared with literature data for air concentrations at a remote site in the Canadian Arctic. Atmospheric concentrations of tri-chlorinated biphenyls were found to be approximately double those reported for Ellesmere Island in the Canadian Arctic, whilst concentrations in samples from Antarctica were very similar to those found in the high Arctic. Most other PCBs were a factor of 2–4 greater in the Canadian Arctic.

The incentives and approaches for modelling chemical fate at a continental scale are discussed and reviewed. It is suggested that a multi-media model consisting of some 20–30 regions, each of which contains typically seven environmental compartments represents a reasonable compromise between the issues of the need for detailed resolution, avoidance of excessive data demands and inherent complexity and transparency. Strategies adopted in compiling the Berkley-Trent (BETR) model for North America are discussed and used to illustrate the issues of selecting appropriate number and nature of segments, treatment of air and water flows and the acquisition of environmental data. It is suggested that GIS software can play a valuable role in gathering and processing such data and in the display and interpretation of the results of the model assessment. The BETR model will be a useful tool for describing the nature of persistence and long-range transport of chemicals of concern in the North American environment.

Ongoing deliberations on the regulation of semivolatile organic chemicals require the assessment of chemical transport in atmospheric and marine systems. The characteristic travel distance was proposed as a measure for the transport potential in air and water. However, the existing definition treats the transport processes separately. It is shown that combined transport in coupled air-ocean systems can accelerate the overall transport into remote regions. Concentration ratios in air and water change with distance from sources depending on the initial concentration ratio and on the difference between the transport velocities. A measure is suggested facilitating the chemical screening with respect to transport potentials in such air-ocean systems. A case study for α and γ-hexachlorocyclohexane shows that the suggested measure qualitatively reveals the transport potentials of these chemicals and exemplifies possible concentration patterns.