Hi - @donblair wrote up a great overview of how particulate air sensing works, here: http://publiclab.org/notes/donblair/05-03-2014/how-do-we-measure-particulate-stuff-in-the-air - but as I understand it, particulate sensing is almost always just particle size and count, without trying to identify what particles are.

@mathew wrote a great overview of lots of different ways that different projects/sensors measure particulates: http://publiclab.org/notes/mathew/05-05-2015/evaluating-low-cost-optical-dust-sensors

And I've been working with him on running a whole batch of them at the same time, to compare: http://publiclab.org/notes/mathew/06-01-2015/plan-for-recording-shinyei-optical-sensors-using-open-pipe-kit

I think it may be hard to measure specific elements in the air - especially at very low concentrations. I don't know much about it, sorry!

I think you are not going to find a low cost means of speciating, of parsing kinds of particles in the air, other than their size.

Speaking of anthropology and particulates. Tim Choy and Jerry Zee have a new wild ride of a paper on particulates that just came out: http://www.culanth.org/articles/772-condition-suspension

I was thinking about this more on my ride home last night. Although you might not be able to say what the particulates are with an inexpensive optical sensor, with two inexpensive sensors placed down wind and up wind of an emission source you could say somewhat convincingly that particles of a specific size came from a specific place, which could be a potent claim to make.

answering your other question: here is a cheap one you can buy https://www.specksensor.com/ I'm not endorsing it, or saying its better than the dustduino, its just one that I know about if you are looking for plug and play.

@nshapiro is right, there is no low cost speciation of dust particles. That is usually done in a mass spectrometer or x-ray diffraction spectrometer in a lab. To extrapolate to concentration you'll need to use a dichotomous sampler with a cyclone or impactor that separates particles by side and deposits them on filters. Generally at least a 24-hour sample is needed to do speciation.

here is a brief summary of several low-cost and DIY optical particle sensors including the Speck. The Dylos 1100 is similarly priced. as @nshapiro said, that's not an endorsement. http://publiclab.org/notes/mathew/05-05-2015/evaluating-low-cost-optical-dust-sensors