‘Policemen working on the Secunderabad-Patancheruvu stretch are accumulating significant levels of platinum, palladium and rhodium in their bodies’

Traffic cops in the city may be soaking up deadly combinations of rare earth metals in toxic concentrations which, alarmingly, are not part of regular air pollution monitoring.

A recently published study shows policemen working and living on the Secunderabad-Patancheruvu stretch accumulating significant levels of platinum (Pt), palladium (Pd) and rhodium (Rh) in their bodies. Bioaccumulation of these metals was attributed to catalytic convertors in automobiles; the devices contain powdered forms of these metals to convert carbon monoxide to carbon dioxide. Exhaust from each vehicle contains these in trace amounts which accumulate over a period of time, researchers say. The study was conducted for over two years and authors measured concentrations of the elements in blood samples of 60 traffic policemen who gave their blood twice, once before and once after the end of their working shift. According to findings published in the Journal of Applied Geochemistry by C.T. Kamala of EPTRI and others, platinum was found to be higher in concentration than other two metals, with average concentration of 6.65 parts per billion (ppb).

Significantly, general population in Hyderabad has far lower levels of rare earth metal concentrations. For comparison, authors’ readings from a person whose exposure to traffic and air pollution was minimal by nature of his work as control. The control concentration of Pt was only 0.0005 ppb.

“Results of the study have revealed higher concentrations of Pt, Pd and Rh among these traffic police operating in high density traffic sensitive zones in comparison to those in industrial and residential areas. In particular among the PGE, platinum accumulation was more,” wrote authors. The study also revealed concentration variations across age. To explain these variations, the authors considered location of residence, besides work location, of the participating cops. They concluded that living close to roads, which ferry large volumes of traffic, further increased blood concentrations of these metals.