Tracing Metal Pollution Back To Its Sources

Main Category: Water - Air Quality / Agriculture
Also Included In: Public Health;  Respiratory / Asthma;  Cardiovascular / Cardiology
Article Date: 21 Nov 2008 - 4:00 PDT

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A new way of pinpointing where zinc pollution in the atmosphere comes from could improve pollution monitoring and regulation, says research out this week in the journal Analytical Chemistry.

Imperial College London researchers say their work is a major breakthrough as current methods for analysing zinc pollution only measure pollution in the atmosphere; they do not trace it back to its source.

Researchers say their method will provide a new tool for policy makers and modellers. A better understanding of zinc pollution sources could inform and improve national and international pollution strategies.

At low levels, zinc is an essential mineral used by plants and animals.

But at higher levels, zinc pollution is suspected of causing cardiovascular, reproductive, immune, and respiratory problems.

Researchers trialled their method on atmospheric samples collected in Sao Paulo, Brazil. They worked in conjunction with researchers from the University of Sao Paulo who wanted to find out where zinc pollution comes from.

The analysis of air samples suggested that a major source of zinc in the city's atmosphere comes from cars and not from manufacturers as previously thought.

Scientists traced zinc pollution to car exhaust fumes and metal friction when cars brake, releasing zinc into the atmosphere. The study's co-author, Dr Dominik Weiss, from Imperial's Department of Earth Science and Engineering, says:

"We need to know where these sources of pollution are coming from because exposure to zinc pollution over a long period of time is a significant concern for the health of residents in big cities such as Sao Paulo or London."

The new method analyses zinc isotopes, which vary according to the pollution source. For instance, zinc isotopes in car exhaust are different from zinc isotopes coming out of industrial smoke stacks. The identity of these isotopes provides the clues to trace zinc pollution back to its source.

Dr Weiss says this technique for analysing isotopes could also be applied to tracing the sources of other metals such as cadmium, copper and thallium. He adds:

"Trace metals have a nasty way of bio-accumulating. They build up through the food chain with toxic consequences. Our new method could help policy makers find some more accurate answers about the true sources of metal pollution."

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Article adapted by Medical News Today from original press release.
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Notes:

1. "Accurate and precise zinc isotope ratio measurements in urban aerosols", Analytical Chemistry, 18 November 2008 (Print publication) Link to paper

Simone Gioia (1), Domink Weiss (2), Barry Coles (3), Tim Arnold (4), Marly Babinski (5) (1)(5)Centro de Pesquisas Geocronologicas, Instituto de Geociencias, Universidade de Sao Paulo, CEP 05508-080, Sao Paulo, SP, Brazil, (2)(3)(4)Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom, Mineralogy, The Natural History Museum, London SW7 5PB, United Kingdom

2. About Imperial College London: Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 13,000 students and 6,000 staff of the highest international quality.

Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve health in the UK and globally, tackle climate change and develop clean and sustainable sources of energy.

Website: http://www.imperial.ac.uk

Source: Colin Smith
Imperial College London