New Delhi: Air-borne particles from the salt mines of Afghanistan are pushing up the levels of air pollutants in Delhi, a team of scientists has found. Initially, the Central Pollution Control Board (CPCB) team had thought that the wind might be carrying sea salt from either the Bay of Bengal or the Arabian Sea. Subsequently, the source of the pollutants was traced to Afghanistan.
A study by the CPCB scientists, including its air laboratory chief Dipankar Saha, has found that about 11 per cent of PM2.5 in Delhi are salt particles.
However, since the study was undertaken during the winter months, the scientists ruled out the possibility of the particles being carried from the sea as the wind direction was generally from the north or north-west during this period.
“We undertook a study, using the trajectory models of the ’s National Oceanic and Atmospheric Adminis-tration. That is when we found that the salt particles were coming from those areas of Afghanistan, which have large salt pans,” Saha said.
The scientists also found the presence of metals such as chromium and copper in the city’s air, which Saha said were being emitted by the electroplating industries in Haryana. PM2.5, which are essentially ultrafine particulates 30 times finer than the human hair, are mainly composed of sulphates, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water.