Particulate matter pollution is considered the biggest health risk. But the WHO Air Quality Recommendations also recommended reducing the daily allowed limits for ozone. That represents a problem specifically for developing countries with many sunny times when ozone concentrations reach the highest levels, leading to respiratory asthma and complications attacks, WHO said. The rules also slice the sulfur dioxide limits. Many countries around the world do not have regulations for air pollution, making control impossible virtually. WHO said the new guidelines, which were established after worldwide consultation with more than 80 leading scientists, supply the basis for all countries to build their own air quality standards and policies supporting health..Variables displaying a univariate association with severe exacerbations were contained in stepwise backward multivariate logistic models to regulate for confounders. In an effort to prospectively validate the association of the PA:A ratio with future severe exacerbations, we then examined the partnership between a PA:A ratio of more than 1 and these occasions as reported in the COPDGene longitudinal follow-up data established and the ECLIPSE cohort, using distinct multivariate logistic-regression and zero-inflated negative binomial models. These models included variables previously reported to become independently associated with acute exacerbations of COPD in the ECLIPSE research8: gastroesophageal reflux disease , lower ideals for the forced expiratory quantity in 1 second , a brief history of severe exacerbations of COPD within the previous year, increased white-cell count, and decreased standard of living as measured by the St.