STRASBOURG, France, Sept 26 (Reuters) - The European Parliament approved new rules to curb air pollution on Tuesday, but environmentalists and the European Union's executive arm accused lawmakers of weakening more ambitious proposals. The measures, first drawn up by the European Commission, seek to bring the EU in line with the United States in capping emissions of particulates, or fine dust, in the air. They would also set tighter limits for emissions of pollutants such as nitrogen oxide and ammonia from different economic sectors including transport, power and agriculture. One provision of the rules would regulate the amount of tiny particulates that get into people's lungs, known as PM2.5 -- fine particulates with a diameter of less than 2.5 micrometres. The Commission said it was concerned by parliamentary amendments that would allow more time for compliance with the existing limits on larger particles known as PM10, beyond January 2010. The changes would also allow cities or communities to exceed daily PM10 limits 55 days per year instead of 35. "Weakening the daily limit value for PM10 means that people whose health is most affected by poor air quality may be exposed to higher pollution levels on significantly more days a year," Environment Commissioner Stavros Dimas said in a statement. Supporters of the parliamentary version said that the daily average was not more important than the annual average limit of PM10, which was tightened in the parliament's version. The Greens party, which said air pollution led to more than 350,000 premature deaths in Europe each year and resulted in health costs of up to 9 percent of the bloc's GDP, called for the proposals to be withdrawn if they were not strengthened. "It seems almost unthinkable that the current rules would be relaxed, but that is exactly the situation we are facing," Finnish Green MEP Satu Hassi said in a statement. In the parliament 571 members voted in favour, 43 voted against, and there were 18 abstentions.
This was the body's "first reading" of the measures. The rules now pass on to be looked at by member states. Once changes are made by EU governments, the measures will go back to the parliament for a second reading. The Commission estimates the health benefits of the measures to be worth at least 42 billion euros a year from 2020 -- six times the costs -- by reducing the number of deaths, sicknesses and related medical care that bad air generates.