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Since the introduction of motor vehicles, practicing engineers and city planner have underestimated the potential of non-motorized transport. As traffic congestion has become severe in many large cities, especially in the developing world, other transport alternatives need to be considered and efficient public transport systems should be given utter priority as they have enormous environmental, social and commercial benefits. There are several options of public transport system. However, in recent times the Bus Rapid Transit (BRT) system option is fast catching up with developing countries. Accra has in recent years been grappling to put in place a public transport system. The BRT concept has been introduced and the World Bank has pledged to support it having ascertained its feasibility [1,2]. Inevitably, there has arisen the need to integrate cycling into the BRT system owing to the increasing use of bicycles in Accra. The integration will afford commuters the opportunity to combined different modes in the most efficient, time and cost-effective manner. This would therefore require strategic planning to link cycle routes to terminals on major route.

The concentration of hydrogen peroxide (HO) in rainwater samples collected between April 2003 and April 2004 in downtown São Paulo were determined. The concentrations of HO ranged from 2.29 to 48.6 μ mol L, with an average value ( = 70) of 13.1 (±11.3) μ mol L. The higher concentrations were observed in spring and summer. The volumeweighted mean (VWM) of the free H was 6.5 μ mol L, corresponding to a pH of 5.2. The analysis of SO, NO, and HCOO, in the same set of samples, showed an average concentration of 11.7 (±10.9), 20.0 (±18.0), and 6.18 (±12.4) μ mol L, respectively. The HCOO concentrations showed correlation ( = 0.43) with HO, which can indicate reactions in aqueous phase where these two species are formed.

The paper presents mutual comparison of samples of individual kinds of precipitation – deposited from fog, precipitation below the tree canopies (the throughfall), and bulk – and wet-only (WO) precipitation on an open place. The throughfall samples reach the highest conductivity values and maximum mean concentrations of individual components with the exception of Cu, Pb, and Cd. The throughfall exhibits also the lowest mean pH values. It was also found that the mean concentrations of several components in fog water are significantly higher than those in the WO samples, but not by one order of magnitude, as it is presented in several papers.

The majority of components in throughfall exhibit considerably higher concentrations throughout the autumn season. On the other hand, concentrations of only several distinct components in fog water exhibit an increase in autumn (K, Mn, Fe, Be, Cd, Al, Ba, and Rb), in effect without any changes remain values and concentrations of pH, Na, F, Cl, Cu, Pb, and As. Concentrations or values of other components are higher in spring than in autumn.

Wales receives rainfall for about 210 days in a year. Chemical characteristics of rainfall and its seasonal variation at the Llandaff campus station located in Cardiff, Wales were studied for the period from June 2003 to July 2004. The station is located in an urban area about 3 km north of Cardiff centre. The rainwater samples were collected weekly using bulk precipitation techniques and analysed for pH and major ion concentration by atomic absorption spectrophotometer (AAS). The samples were collected from two sample collectors at different heights and separated by about 200 m, the ground level of house sample being designated (Hs) and upper level of roof sample (Rs).

Over the period of investigation, the volume of rainfall measured was almost the same for Hs and Rs. The pH of Hs and Rs was 5.6 and 5.3, respectively. Average wet deposition of ions in parts per million (ppm) of Hs and Rs were: Mg (0.56, 0.73), Na (7.3, 8.0), Ca (3.17, 3.10), K (3.03, 1.76), and Cl (10.6, 12.0). The ratio of the total average concentration of chloride to that of sodium for Hs and Rs are 1.45 and 1.5, respectively, which is close to the ratio of seawater, 1.8. Seasonal variations for some major ions appear to be pronounced. Generally, the maximum pH occurred in the autumn season and the minimum pH in winter season for both samples. Dust, insects, and tree debris found in both samples may have been the reason for the increased pH, and was more pronounced in the Hss. This study provides the influence of wet deposition in Cardiff.

Based on the determination of Zn, Cu, Pb, Ni, and Cd in soils, street dusts, and sediments from the urban area of Coventry, UK, two sets of bioaccumulators were located around Coventry City Centre. The first set of 12 peat-containing seed trays were located on a busy road traffic island with a second set placed for comparison with a rural area. One tray was removed each month from each site for analysis. Whilst the concentrations of most metals were higher in the urban area, the temporal trends were similar, with the concentrations of Pb indicating that urban levels had declined. The second set of biomonitors of three moss bags were located at 16 sites in the City Centre; one bag was removed every 2 months, making a 6- month study in all. The temporal trends for the moss bags were generally increasing concentrations with time, although two sites declined in the last sampling month. Concentrations of Zn and Cu in the street dusts, sediments, and soils were high, as was Zn in both biomonitors and Ni in just the moss bags.

One of the most air-polluted cities in the world is Beijing, where PM2.5 was sampled on filters by a mini-volume sampler (200 L h) and coarse particles on collection plates by means of the passive sampler Sigma-2. From 15 January to 5 February 2005, sampling was carried out in two modes, by collecting particles over periods of several days separated in day and night samples, and alternately during night and daytime in intervals of 12 h. The sampling site was located in north-west of Beijing. Automated microscopic image analysis of coarse particles showed significantly differing size distributions of particle fractions between 3 and 100 μm for day and night samples. The different size distributions could be attributed to varying conditions of atmospheric dispersion and particularities due to local traffic. Elemental carbon containing particles accounted for 10% to 30% of total coarse particles. Scanning electron microprobe analyses identified a wide range of different anthropogenic and geogenic particles. Average PM2.5 concentration during daytime was about 75μg m in the first, 200 μg m in the second, and 64 μg m in the third week. Peaks of daily PM2.5 concentrations reached more than 300 μg m in the second week. Trace metals such as Pb, As, Cu, and Zn showed similar temporal courses. Several different sources of aerosols were identified by means of scanning electron microscopy (SEM). Backward trajectories indicated that highly polluted air masses reaching Beijing during the second week were advected from south. These air masses passed with low velocities industrial areas in the south and the whole city before reaching the sampling site, whereas air masses entering Beijing during the first and third week came from less industrialized regions in the north. Due to the specific spatial distribution of air pollution sources in the area of Beijing, trajectories could provide a simple approach to an air pollution forecast

In megacities like São Paulo, which is responsible for approximately 16% of Brazil’s gross national product (GNP), the subway serves as a major transportation mode, transporting 2.7 million people daily. The underground portion of the subway system is a confined space that may permit the concentration of contaminants either from the outside atmosphere or generated internally. The objective of this study is to evaluate the air quality of two of São Paulo’s subway stations (Clínicas and Praça da Sé), by identifying the fungi species, the nitrogen dioxide (NO), BTEX (benzene, toluene, ethylbenzene, and xylene), and particulate material (PM) concentrations. Afterwards, a comparison of the internal pollutants concentration values with external atmosphere parameters is performed.

A study has been carried out to evaluate the air quality impact under different typologies of motorways in Portugal. The monitoring of atmospheric pollutants with the use of indicative and continuous simultaneous measurement methods was the strategy to evaluate the conformity with National/ European air quality legislation. This paper gathers results obtained in two major air quality-monitoring campaigns. Meteorological and traffic data were also collected. Benzene showed a decreasing linear dispersion behaviour for all the considered motorways and seems to be the best descriptor to evaluate the impact on air pollution through indicative measurements.

The Alpine environment as a sensitive region is heavily influenced by major traffic routes. Within the project ALPNAP (monitoring and minimization of traffic-induced noise and air pollution along major Alpine transport routes) the integration of advanced scientific methods of monitoring and simulating the air quality distribution and noise propagation is a key aspect for the impact analysis on human health. A methodology for measurement strategies and model simulations for air pollutants will be demonstrated for the Brenner traverse. First, results of a field measurement campaign give detailed insights of the complexity of the atmospheric conditions and the distribution of air pollutants in the Inn valley.

Elevated platinum group elements (PGEs) concentrations have been reported at Summit in Central Greenland. Automobile catalysts and Russian smelters have been suggested as potential sources of PGEs at Summit, but the relative importance of these sources still needs to be determined. Here, we provide a source characterization based on relative PGE concentrations and air mass modelling. This study suggests that both catalysts and smelters are potential sources of PGE in Greenland, but that the contribution of smelters is relatively limited. The larger contribution from catalysts is probably the result of higher emission rates related to the number of vehicle equipped with a catalyst. The presence of automobile catalysts-derived PGE in Greenland suggests that automobile catalysts are resulting in widespread contamination.