reliability and usage of data as evidence

[Sören]

Hi guys,

I am writing to you because I am interested in the AQE. I would like to know whether the measurements and monitorings produced with your devices have ever been used as legal evidence to support a case against a polluter/polluting company, etc.

Is the data produced by these devices sufficiently accurate and reliable that it would be accepted in court as evidence? How much error has been recorded?

Do you have any experience on proofing the source of pollution and linking pollution to one particular source rather than accumulated pollution?

Also, do you have experience in demonstrating levels of pollution in one community as opposed to a "healthy" community as comparable population?

I am particularly interested in monitoring the pollution deriving from open-pit coal mining and coal fired power stations.

Thanks for any help and thoughts on this!

Sincerely,
Sören

[vicatcu]

Sören,

Take this with a grain of salt, I am not a lawyer, disclaimers etc. 

I don't know of any examples of the data collected by the Air Quality Egg community being used as legal evidence. That was really never part of the mission of the project, which was rather to get individuals engaged in a dialogue about Air Quality based on broadly collected measurements. And even then, the Air Quality Egg hardware was never designed to be a substitute for an EPA-level scientific instrument. I think you'd be hard pressed to make a case based on Air Quality Egg due to the inherent variations among sensors and the lack of calibration data and periodic re-calibration that would be needed for rigorous longitudinal data collection. 

We in the Air Quality Egg community, as well as we as a broader community of people interested in air quality measurement, are continuously working toward using more accurate sensors while keeping costs low enough to enable wide deployment. I'm not sure we will ever realistically be able to overcome the financial burdens that go along with "admissible in court" in a project like ours where we, as a community, are philosophically committed to the idea that, where there is a tension between "more available sources of data" and "higher quality data," the prior prevails. That has as much to do with inclusion being a guiding principal as economics.

Kind Regards,

Vic

[NeilH]

Hello Soren
You bring up a good point about how a measurement may be used in a legal process - this could be anything from a court proceeding to making an input to a legally established oversight board such as Air Quality Management.

I'm not a legal expert, but I understand the core of making such readings are
1) Traceable readings - this is a big deal in any measurement situation, validating that the readings units are traceable to a (national) standard with a defined error margin. Imagine if you weren't sure that the weight of vegetables you had purchased weren't accurate. That the shop keeper said it was 2kgs when in practice the scales were "fixed" to over-read and was actually 1.9kgs. A very old trick, and most regional governments have weights and measures division to manage accurate measurements. The trace-ability requirements vary by region - eg EU or USA.

2) An individual stating they manage the instrument - from geographical location to readings and dates taken (data quality plan). That is the readings have no validity unless given a context.

3) Other issues as to what do those measurement numbers mean at that location, which local experts and legal people need to figure out.

Its a learning curve independent of any measurement tool, so good luck with it.

[Cesar Garcia Saez]

I'm sharing all these EPA papers on the topic so you can check by yourself:

Conclusions:

http://www.epa.gov/ttn/amtic/files/2014conference/wedtribduvall.pdf

Cheap sensor evaluation:

http://www.epa.gov/airscience/docs/sensor-evaluation-report.pdf

Citizen's guide to choose your own sensor:

http://www.epa.gov/airscience/docs/air-sensor-guidebook.pdf

Evaluating MICS-2710 (cheap NO2 sensor used in several citizen sensors):

http://www.takingspace.org/evaluating-low-cost-gas-sensors/

For me, the result is: no, they can't be used for comparison as sensors are sensors+protocols to ensure reliability as Neil mentions. As there are no protocols or standardisation on these cheap sensors (and sensors are not reliable) you are out of luck. However, they point to several scenarios regarding recommended usages depending on price range.

For me, this is the ultimate form of public debate, when several EPA papers consider and include AQE-like projects for their evaluation and propose that they are included in future measurements as didactic/personal platforms.

It's been almost 6 months since I reviewed this papers for the first time, but these are the conclusions I extracted then ;)

Best,

César

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[Dario Salvi]

The EPA has a very good collection of reports:

http://www.epa.gov/heasd/airsensortoolbox/

[Dario Salvi]

You might want to check this one also: http://www.everyaware.eu/resources/deliverables/D1_1.pdf