KARACHI: Describing air pollution as the world’s single biggest environmental health risk, experts at a three-day international conference, which concluded at Karachi University (KU) on Sunday, called for collaborative research efforts to determine the impact of specific sources of air pollution on human health.

They were speaking at the fifth international conference on ‘Environmental horizon, sounding the alarm! Environment, climate change and health’ organised by KU’s department of chemistry and Office of Research Innovation and Commercialisation (ORIC), and International Centre for Chemical and Biological Sciences (ICCBS).

Sharing global concerns on air pollution, Dr Haider A. Khwaja from Wadsworth Centre at the School of Public Health of University at Albany in New York, said that air pollution was a serious public health issue the world over as population-based studies had documented health risks resulting from short-term exposure to air pollutants.

“The World Health Organisation reports that in 2012 around seven million people died — one in eight of total global deaths — due to exposure to air pollution. This data confirms that air pollution is now the world’s largest single environmental health risk,” he noted.

He said that the South Asian and Western Pacific regions had the largest air pollution-related burden in 2012 with 2.6m deaths linked to outdoor air pollution and 3.3m deaths related to indoor pollution, according to WHO.

A significant number of these deaths, he said, occurred due to stroke and cardiopulmonary diseases. These findings were not based on a significant increase in pollution but rather on improved knowledge of the links between air pollutants and cardiopulmonary diseases.

Dr James J. Schauer, a senior civil and environmental engineer heading the Wisconsin State Laboratory of Hygiene at the University of Wisconsin-Madison, said that the association of atmospheric particulate matter particles with adverse health effects had been well established and led experts to develop standards on these pollutants and implement control measures.

According to him, different strategies can be used in air pollution control programmes to reduce the impact of particulate matter, also known as particle pollution, given the complex nature of the sources of these pollutants.

He emphasised the need for collaborative efforts between atmospheric science studies and epidemiological and toxicological studies to establish how specific sources of air pollution were affecting human health.

Sheryl H. Ehrman from Davidson College of Engineering, San Jose State University, USA, informed the audience that anthropogenic pollutants had been successfully reduced in the mid-Atlantic region of the United States, resulting in improved air quality.

However, she said that parts of the mid-Atlantic were still non-attainment regions (areas which are considered to have air quality worse than the National Ambient Air Quality Standards as defined in the Clean Air Act Amendments of 1970 of the United States).

The ozone, she pointed out, was a secondary air pollutant, formed by reactions between volatile organic compounds and nitrogen oxides. Ozone precursors were mainly emitted by power plants, motor vehicles, industrial operations and biogenic sources.

“In the past several years, a new influx of emissions associated with hydraulic fracturing-based production of natural gas in the Marcellus Shale (the largest gas field in the US) may be counteracting the benefits that have been gained. On the flip side, low-cost natural gas could replace coal as fuel for power plants, potentially reducing emissions,” she observed.

Another speaker, Parisa A. Ariya of the department of chemistry and department of atmospheric and oceanic sciences, McGill University, Montreal, Canada, shared that the International Panel for Climate Change (IPCC) and WHO had identified airborne particles as a research priority of the utmost importance.

She said the IPCC pointed to the importance of aerosol-cloud processes due to their impacts on the absorption and scattering of irradiation, altering the earth’s climate whereas WHO predominantly considered aerosols to be health hazards.

Former federal minister for science and technology Atta-ur-Rahman spoke about how progress in science and technology had dramatically changed socio-economic conditions in different countries.

Director ICCBS Prof M. Iqbal Choudhary said biodiversity was a manifestation of chemical diversity and plants contained a fascinating array of highly evolved, specific and effective gene products.

Published in Dawn, January 15th, 2019