I am an atmospheric scientist, passionate about fighting air quality, especially in polluted but under-studied/monitored places across the globe. I love starting up and exploring air quality projects that give the public data, insights and voices they previously didn't have. I am convinced doing so will have a transformative effect on public health and the environment.
And this is my favorite figure:
This sounds like an impactful project with a solid business plan to address truly unmet needs in Dhaka. As someone always working to connect with local populations on public health issues (specifically air pollution in my case), I'm most immediately struck by the potential of your project to enhance/complement others by enabling public outreach opportunities to perhaps traditionally difficult to access and under-served populations. For instance, I could imagine various public health orgs finding great value in tagging along in your 'taco truck' model and giving short workshops/demos on various topics of interest to customers. Perhaps some public health orgs would be willing to invest in the base infrastructure of your program because of that potential access.
In case it is of interest, I thought I'd also mention another funding opportunity, specifically for an in-country partner: -USAID's PEER program - this could provide funding to an in-country partner to work on a research-related aspect of your idea. These grants do typically have a more academic feel to them, but they do actively look to fund practical research that directly feeds into an international development solution and in practice can be quite broad in scope. Bangladesh is an eligible country: http://sites.nationalacademies.org/pga/peer/index.htm
It's inspiring to see a group put an awesome, impactful idea out into the world and work to make it happen. Best of luck, Christa Hasenkopf Co-Founder of OpenAQ