Poor air quality causes some seven million deaths annually, the World Health Organization said Wednesday, adding more than 90 percent of the global population is breathing in high levels of pollutants. "Air pollution threatens us all, but the poorest and most marginalized people bear the brunt of the burden," WHO chief Tedros Adhanom Ghebreyesus said in a statement. Fresh data from the UN health body showed that every corner of the globe is dealing with air pollution, although the problem is far worse in poorer countries. WHOs study, which examined health-hazardous levels of both outdoor and household air pollution, found that "around seven million people die every year from exposure to fine particles in polluted air". More than 90 percent of deaths linked to air pollution occur in low- or middle-income countries, mainly in Asia and Africa, it found. "This is a very dramatic problem that we are facing," Maria Neira, the head of the WHOs department of public health and environment, told reporters in a conference call. Dangerous particulate matter can cause diseases like strokes, heart disease, lung cancer and respiratory infections such as pneumonia, WHO said. Particularly worrying, the agency added, was that more than 40 percent of the global population still does not have access to clean cooking fuels and technologies in their homes. The use of dirty cooking fuel, like burning charcoal, is a major source of household air pollution, which is estimated to cause some 3.8 million premature deaths each year. Wednesdays report said access to clean fuels was increasing in every region, but warned "improvements are not even keeping pace with population growth in many parts of the world", pointing especially to sub-Saharan Africa. Outdoor air pollution was meanwhile linked to 4.2 million fatalities annually.