Bricks reveal recent history of heavy metal pollution in soil around a north Indian city

Up to now, geochemical monitoring of atmospheric heavy metal pollution has been limited to the use of peat, ice deposits and aquatic sediments as sample types. These systems are open, dynamic and easily affected by climatic variations. In a recent report, Shrivastav et al. (Environ Mon Ass 1996;40:271–278) have suggested the use of bricks as a geochemical monitor of heavy metal fallout and their study has clearly demonstrated the practical feasibility of the above concept at least in some parts of the world. However, more research is required in order to understand the suitability of using bricks as a geochemical monitor of heavy metal fallout. As part of our continuing research in this direction, in this article we report on the history of heavy metal pollution in the soils of Agra since 1900, that have been traced by analysing bricks of different ages collected from the old buildings/monuments. The study indicated that the soil concentrations of lead, zinc and chromium rose initially until between 1950 and 1960 and then fell sharply especially over the last 2–3 decades, which can be explained as an outcome of socio-economic fluctuations on a local scale and climatic changes on a global or regional scale.