Swiss cantons have announced a package of measures aimed at fighting the country's increasing smog problem.
The wide-ranging plan foresees reducing motorway speed limits and banning wood fires at peak pollution times but also calls for more government support to help tackle the causes of smog.
Many urban centres in Switzerland regularly suffer above-average levels of fine particle smog and high ozone levels in both winter and summer, leading to health concerns.
Last winter 11 cantons with high smog concentrations took emergency action. This latest plan is designed to provide a coordinated approach, according to the Conference of Cantonal Building, Planning and Environment Directors.
Presenting their concept on Tuesday in Flims, canton Graubünden, where parliament is currently holding its autumn session, the directors said the 26 cantons had agreed on a three-level plan.
The first level concerns information and recommendations whereas the second and third involve more concrete measures.
This would include reducing motorway speed limits to 80kmh and stopping wood fires both indoors and outdoors.
It also foresees the banning of diesel machines without particle filters in peak smog times. The measures would stay in place until the smog levels had dropped below 50 micrograms.
Calls for support
The cantons - whose job it is to implement environmental measures - also called on the government to step up its anti-pollution drive, which was announced last January. The action plan is designed to reduce levels of diesel emissions and soot.
"The fight against smog and ozone is most effective when the pollution output is constantly reduced at source," said a conference statement. "Impulses can also be created by financial incentives."
These two measures were the responsibility of the government, it added.
In June the government announced the second phase of its anti-pollution programme, which calls for all new diesel cars, minibuses and vans to be fitted with special filters from 2007 and tractors from 2009.
A final decision on the move is expected at a later date after the government has consulted with the World Trade Organization (WTO), the European Union and the European Free Trade Association (Efta).
There was a mixed response to the proposals from various lobby groups. While the main Swiss car lobby group, Touring Club Switzerland, rejected the 80kmh limit as a "placebo measure", environmental organisations and health groups said the measures did not go far enough.
For its part, the environment office was quoted as saying it was sceptical about the speed limits, although they could be used as temporary measures.
Particles found in the air, which are natural or man-made and include soot, heavy metals and sulphates, are said to cause respiratory problems and could lead to lung cancer.
Experts say dust particles cause 3,700 premature deaths in Switzerland a year and annual extra health costs of SFr4.2 billion ($3.4 billion).
swissinfo with agencies
Three million people in Switzerland – more than 40% of the population – live in regions that record above-average fine particle levels.
The Federal Environment Office says 21,000 tons of fine dust are emitted in Switzerland every year.
56% comes from the private and public use of mechanical abrasion.
The rest comes from diesel motors (17%), wood burning (15%), other burning (10%) and petrol, natural gas and natural oil (2%).