Recent studies have pointed to evidence that fine particles in the air could be significant contributors to respiratory and cardiovascular diseases and mortality. Epidemiologists looking at the health effects of particulate pollution need more information from various receptor locations to improve the understanding of this problem. Detailed information on temporal, spatial and size distributions of particulate pollution in urban areas is also important for air quality modellers as well as being an aid to decision and policy makers of local authorities. This paper presents a detailed analysis of temporal and seasonal variation of PM10 and PM2.5 levels at one urban roadside, one urban background and one rural monitoring location. Levels of PM10, PM2.5 and coarse fraction of particulates are compared. In addition, particulate levels are compared with NO2 and CO concentrations. The study concludes that PM10 and PM2.5 are closely related at urban locations. Diurnal variation in PM 2.5/PM10 ratio shows the influence of vehicular emission and movement on size distribution. This ratio is higher in winter than in summer, indicating a build-up or longer residence time of finer particulates or washout due to wet weather in winter. In the second part of this study, a disease burden analysis is carried out based on the dose-response relationships recommended by the UK Committee on the Medical Effects of Air Pollution. The disease burden analysis indicates that if Marylebone Road (MR) levels of PM 10 were prevalent all over London, it will result in around 2.5% increase in death rates due to all causes. Whereas, if Bloomsbury (BB) levels were prevalent in London, which is more likely to occur as this is more representative of the urban background environment to which people in London are likely to be exposed, the corresponding increase would be around 1.7%. Considering this, in London, at Bloomsbury levels, 973 deaths and 1515 respiratory hospital admissions (RHA) are attributable to PM10 while 2140 RHA are attributable to NO2. After deducting the disease burden due to background levels at Rochester (RC), PM10 emission caused by anthropogenic activities in London equates to 273 additional deaths and 410 additional RHA, while NO2 account for additional 1205 incidences of RHA.