Air pollution is associated with increased level of exhaled nitric oxide in nonsmoking healthy subjects.

The authors sought to determine which air pollutant is responsible for the increase in exhaled nitric oxide observed in healthy subjects. Exhaled nitric oxide was measured in 16 nonsmoking healthy subjects on 14 workdays, during which there were varying air-pollution levels. Contamination of samples by ambient nitric oxide was excluded.

A field intercomparison and fundamental characterization of various dust samplers with a reference sampler.

The European Economic Community Council Directive 80/779/EEC describes air quality limit values and guide values for sulfur dioxide and suspended particulates. However, article 10, paragraph 1 does not define well enough the reference method required, amongst others, for the gravimetric measurement of suspended particulates. It is explicity stated in article 10, paragraph 5 of the directive, that "the commission shall, in selected locations in the member states and in cooperation with the latter, carry out studies on the sampling.