As the 10th Annual UN Climate Control Conference continues in Buenos Aires, drivers of diesel-powered cars without particle filters learned they may be occasionally banned from many European city centers, including many in Germany.

City officials are resorting to the bans as they struggle to meet the requirements of tougher new European Union clean air guidelines set to go into effect in 2005.

Though the new limits imposed on many air pollutants, including microscopic particulate matter commonly emitted from diesel-powered cars without filters, were adopted in 1996, environmental experts say government officials have not taken advantage of the long transition period. The resulting bans are something of a measure of last resort.

Banned from city centers

Occasionally banning diesel powered cars without particle filters from city centers would help keep the amount of microscopic particulate pollution, which a German Federal Environmental Agency study showed contributed to the premature death of 14,000 people last year, within acceptable levels. The particulate pollution has been linked to cancer and a host of other health problems.

According to the Council of German Cities, the bans may start as soon as February, when weather conditions tend to increase the particulate pollution problem.

"We assume that there will be driving bans in all the big German cities, in built-up areas and indeed several times a year depending on weather and traffic conditions," Jürgen Resch of the DUH, a German Environmental organization, told Reuters.

The bans have also received the blessing of Germany's environment minister, Jürgen Trittin.

Filters to be introduced

In a few years' time, diesel powered cars without filters will be less of an issue. In July, after months of resistance, the German car industry agreed to start installing filters in all its new domestic diesel models by 2009.

Previously, German car makers claimed that installing such filters would be too expensive, but they eventually conceded to their customers' demands, many of whom wanted the filters. If properly fitted, filters can reduce particulate emissions by up to 99 percent.

Though filters will be standard in all new models from 2009 onwards, that still leaves the matter of the many diesel cars which will be sold without filters over the next four years, and those already on the road. Diesel cars currently make up 40 percent of all new European sales.

Some German car parts makers, including HJS, have been manufacturing filters priced at around €700 ($934), which can be installed in older model cars.