Last week many Gladstone residents saw the Four Corners report on coal mining in the upper Hunter Valley, "A Dirty Business”. The story, which is available at www.abc.net.au/4corners, highlighted local community demands to know more about the industry air emissions in their region.

I took two things from this story. Firstly, that the Gladstone community is not alone in being concerned about the potential health impacts of air emissions. Secondly it showed that the Gladstone community, compared to the Hunter Valley, is relatively more advanced in our discussions about air quality.

One important part of any discussion about air quality is the Australian Government’s National Pollutant Inventory (NPI). The NPI tracks pollutants that may affect human health or the environment and the latest NPI data has just been publicly released at www.npi.gov.au.

NPI data is based upon industry self-reporting of their emissions. Understandably, many people I speak to see this as a weakness and so scoff at NPI data.

Under the NPI rules, industries can either measure their emissions directly or calculate them based upon the known chemistry of their processes or based upon commonly accepted NPI emission factors, which are like “rules of thumb”. Once again, some people are suspicious of NPI data as it is not all based upon directly measured information.

Each of these three approaches has its strengths and weaknesses. So while direct measurement is generally the preferred method, it is not necessarily always the best way to gather emissions data.

This is because even when using direct measurement it is still not physically possible to weigh all the emissions from a process, particularly on a large site. Rather direct measurement is based upon the results of periodic samples or monitoring of part of an emission stream and calculated by making a number of assumptions about the process.

As a result, industry usually uses a combination of these three approaches to provide NPI data.

A key to ensuring NPI data is accurate is the benchmarking, review and industry comparisons made by the Australian and Queensland governments. If the data doesn’t measure up, the Queensland Government can and has rejected data and required that NPI data be resubmitted.

So what does the latest NPI data show? In my next column I will present the consolidated NPI emissions of Gladstone Industry Leadership Group (GILG) members based upon the data released this month.

In the meantime if you’d like to ask questions about the NPI, please check out our forum topics at www.gilg.com.au,

If you would like to have your say and don't know how, please click on this link which shows you how to register and make a comment, anonymously if you wish, cheers, Kurt.

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