Airborne particulate matter at a bus station : concentration levels and governing parameters

Traffic emissions are an important contributor to ambient air pollution, especially in large cities featuring extensive and high density traffic networks. Bus fleets represent a significant part of inner city traffic causing an increase in exposure to general public, passengers and drivers along bus routes and at bus stations. Limited information is available on quantification of the levels, and governing parameters affecting the air pollution exposure at bus stations. The presented study investigated the bus emissions-dominated ambient air in a large, inner city bus station, with a specific focus on submicrometer particles. The study’s objectives were (i) quantification of the concentration levels; (ii) characterisation of the spatio-temporal variation; (iii) identification of the parameters governing the emissions levels at the bus station and (iv) assessment of the relationship between particle concentrations measured at the street level (background) and within the bus station. The results show that up to 90% of the emissions at the station are ultrafine particles (smaller than 100 nm), with the concentration levels up to 10 times the value of urban ambient air background (annual) and up to 4 times the local ambient air background. The governing parameters affecting particle concentration at the station were bus flow rate and meteorological conditions (wind velocity). Particle concentration followed a diurnal trend, with an increase in the morning and evening, associated with traffic rush hours. Passengers’ exposure could be significant compared to the average outdoor and indoor exposure levels.

Down the aisle : the effects of technological change on retail workers skills

Reconfiguration of corporate structures and the retailer-supplier interface in the retail industry have restructured product markets and supply chains, as well as supermarket employment, over the past decade or so (Baret, Lehndorff & Sparks 2000; du Gay 1996). Various studies have examined the consequent changes in labour usage practices within supermarkets or superstores (Baret et al. 2000; Marchington 1995; Penn & Wirth 1993; Sparks 1992; Dawson, Findlay & Sparks 1987, 1986). Commonly, this literature explores the interplay between shifts in the structure of the labour market, broader societal trends and retailers’ employment strategies. One study found that domestic and gender dimensions, accompanied by industrial relations regimes, exert considerable influence on patterns of labour usage (Baret et al. 2000). However, while the types of labour usage and the drivers of changes to labour usage patterns have attracted significant academic attention, research has largely overlooked the ways in which the nature of supermarket work has evolved as a result of changing technology, which effectively bolsters managerial prerogative, and which has affected the skill levels of workers in the industry (Marchington 1995).