Experimental study of negative corona discharge in pure carbon dioxide and its mixtures with oxygen

The products of a negative corona discharge in both pure CO2 and mixtures of CO2 + O2 have been studied using a coaxial cylindrical electrode geometry with particular emphasis on the production of ozone. The discharge current in pure CO2 was found to be highly sensitive to the presence of trace concentrations of molecular oxygen and to changes in the flow speed through the discharge. The effect of dissociative electron attachment to ozone on the discharge current was studied by measurements of ozone and CO production. The ozone concentration increases monotonically with increasing content of oxygen in the mixture with carbon dioxide, whereas the CO concentration exhibits a flat maximum for oxygen concentrations of around 4%. A simple kinetic model of the dominant chemical processes is described and compared with the experimental results

Local action on outdoor air pollution to improve public health.

OBJECTIVES: The National Institute for Health and Care Excellence, jointly with Public Health England, have developed a guideline on outdoor air pollution and its links to health. The guideline makes recommendations on local interventions that can help improve air quality and prevent a range of adverse health outcomes associated with road-traffic-related air pollution. METHODS: The guideline was based on a rigorous assessment of the scientific evidence by an independent advisory committee, with input from public health professionals and other professional groups. The process included systematics reviews of the literature, expert testimonies and stakeholder consultation. RESULTS: The guideline includes recommendations for local planning, clean air zones, measures to reduce emissions from public sector transport services, smooth driving and speed reduction, active travel, and awareness raising. CONCLUSIONS: The guideline recommends taking a number of actions in combination, because multiple interventions, each producing a small benefit, are likely to act cumulatively to produce significant change. These actions are likely to bring multiple public health benefits, in addition to air quality improvements