# How to determine source of air pollution

It should be determined by some metal markers (meaning originating from traffic etc.) but I cannot find any source which would describe it. Thanks.

• Hi, Can you be more specific? What do you want to do? What is your budget? What type of pollution? – G M Apr 12 '14 at 13:03

The main idea is the following: you will need multiple sampling points and record enough data to obtain a representative dataset. Then when drawing wind roses with high percentiles (let say P95 or above) you will be able to easily point out an unique source of a relevant and exclusive pollutant.

But of course, reality is much complex... And there are some adverse effects that you must address before pointing out the source with a reasonable confidence.

First you better be not so close to the source, in order to measure immission instead of emission. Then environment and local conditions will average out. And wind speed, wind direction and concentrations become meaningful. In this case high percentiles likely originate from your source.

Second, your analyte must be relevant and if possible exclusive from your source. Measuring CO2 is not a good choice when monitoring traffic (it is stable, widespread thus global and not exclusively produced by traffic), NO is a better one because it is local, reactive and strongly related to high compression ratio thermal engine combustion source.

Third, if there are multiple isotropic sources, you will get nothing useful using wind roses. And your problem becomes really tricky.

All catalytic converters faintly emit heavy metal-containing microparticles continuously detached from the catalytic wash bonded upon their ceramic matrix. Correlate your pollutant(s) with those particles and you establish proximity (though not causality).

Isotopic labeling of emissions (C-13 in fuel, O-17,18 in air) then expensively establishes causality. You could use conceivably use inert taggants like $\ce{CF4}$, $\ce{SF6}$, $\ce{NF3}$ injected into the exhaust stream, but then Enviro-whiners will attack (Greenhouse Effect, Global Warming, Climate Change). There is no postulated loss so small that social advocacy will not demand vastly greater real world losses to possibly prevent it.

http://www.ncbi.nlm.nih.gov/books/NBK98071/
Particulates