Some less polluted regions have had little or no dimming.

As an example, take the history of one particularly polluted region of the tax code: the special rules for oil companies.

Growing numbers of pilgrims and tourists are visiting the area, and it is now one of the most polluted regions of the Himalayas.

"We are one of the most polluted regions in Europe."

This provides good estimates of the background carbon dioxide levels and isotopic ratios, rather than the values that scientists would find at more polluted regions.

The rules categorized polluted regions from marginal to severe and laid out timetables to make improvements by category.

The agency believes that investors will refuse to buy plants in the polluted region if they will also have to pay for cleaning up the environment.

The Niger delta is one of the most polluted regions in the world.

Amendments to the Clean Air Act require companies in some polluted regions to increase the number of employees using car pools or mass transit.

Indeed, our aim to become the least polluted region in the world cannot but be to our advantage.