Gypsy-gadje relations are made even trickier where traditional groups still observe laws shaped by a sense of imminent defilement, the idea (more understandable when framed within an Indian caste system) that contact with gadje, particularly sexual contact, is a kind of pollution punishable by banishment.

ECONOMIST: Europe��s spectral nation

As Eric Hobsbawm has said, terrorism is a new kind of urban pollution, and the pollutant is an insidious and chronic disquiet.

NEWYORKER: Laureate of Terror

Obama told senators that he believed the best way to make a transition to a clean-energy economy is with a bill that "makes clean energy the profitable kind of energy for America's businesses by putting a price on pollution, " the statement said.

CNN: Top issues: Energy and environment

The Recovery Act will double the supply of renewable energy, but the only way to truly spark an energy transformation is through a gradual, market-based cap on carbon pollution so that energy, clean energy is the profitable kind of energy.

WHITEHOUSE: Town Hall in Arnold, Missouri