Pakistan — Experts at Pakistans Space and Upper Atmosphere Research Council (Suparco) have linked the recent occurrences of mist and fog over the plains of Punjab province in the country and a few states in India to the higher demands for energy, mobility and communications. According to Badar Ghauri, senior researcher at Suparco, the scope and magnitude of the environmental consequences of these demands seen in recent decades were far reaching, especially with respect to air pollution at local and regional levels. The new scenario encompasses complex inter-linkages of several issues, including air pollution, haze, smog and global warming, he said here Sunday. The most visible impact of air pollution is the haze, a brownish or grayish layer of pollutants and particles which are generally named as Atmospheric Brown Clouds (ABCs), he adds. Ghauri said the Asian ABC first came to prominence when scientists from America, India and Europe published the findings of the Indian Ocean Experiment (Indoex) carried out in February 1999, in the islands of the Maldives, revealed that a 3 km-thick toxic umbrella of Brown Cloud, stretches over Afghanistan, Pakistan, Bangladesh, Bhutan, India, Maldives, Nepal, and Sri Lanka amongst the most densely populated places in the world. These brown clouds or haze particles consist of black carbon (soot), sulphates, nitrates, ozone and trace elements amongst several other toxic organic pollutants, which can be transported far beyond their source region, particularly during the dry season. The dominant sources of major components of ABC are black carbon and other aerosols and are open burning of biomass, diesel engines, and the residential burning of solid fuels such as coal, wood, dung, and agricultural residues that pervades many regions in Asia. The potential consequences of this brown haze involve melting of glaciers, change in rainfall pattern, damage of agriculture productivity and adverse impacts on human health, Ghauri said. These brown clouds absorb incoming solar radiation and prevent it from reaching the surface, warming the atmosphere in the process. Talking about effects of black carbon laden brown haze, Ghauri said that besides climate change it had also been reported for having significant effects on human and agriculture health. Brown clouds contain a variety of toxic aerosols, carcinogens and particles including particulate matter of less than 2.5 microns in width. The adverse health effects of such airborne particles have been documented in many parts of the world and the most serious health impacts of particles associated with the ABC include cardiovascular and pulmonary effects leading to chronic respiratory problems.