Small, Smart, Fast, and Cheap: Novel Monitoring Devices for HAP Studies
Review of 20+ years of work in our group to develop monitors is found at Pillarisetti A, Allen T, Ruiz-Mercado I, Edwards R, Chowdhury Z, Garland C, Hill LD, Johnson M, Litton CD, Lam NL, Pennise D, Smith KR, 2017, Small, smart, fast, and cheap: Microchip-based sensors to estimate air pollution. Sensors 17, 1879.
To facilitate research and evaluation of HAP in village settings, we develop battery-operated, microchip-based devices to directly measure parameters of interest rather than rely on expensive commercial monitors, techniques requiring laboratory back-up, or imprecise and intrusive social-science-based approaches, such as questionnaires and observation. In all cases, in addition to developing the technology itself, we develop the software for handling the sometimes large datasets that result. Most of these devices have been developed in collaboration with colleagues, particularly Dr. Tracy Allen of EME Systems.
UCB - Particle and Temperature Sensor (UCB-PATS)
Around 2000, our research group developed an inexpensive particle monitor (UCB-PATs) based on a widely sold smoke alarm by First Alert. See the short history of its development. Below are the original papers describing the theory, lab, and field validations:
- Litton CD, Smith KR, Edwards R, Allen T. Combined optical and ionization measurement techniques for inexpensive characterization of micrometer and submicrometer aerosols, Aerosol Science and Technology, 38:1054–1062, 2004.
- Edwards R, Smith KR, Kirby B, Allen T, Litton CD, Hering S. An Inexpensive Dual-Chamber Particle Monitor: Laboratory Characterization, Journal of the Air and Waste Management Association, 56:789-799, 2006.
- Chowdhury Z, Edwards R, Johnson M, Shields KN, Allen T, Canuz E, Smith KR, An inexpensive light-scattering particle monitor: field validation, J. Environ. Monit., 9: 1099–1106, 2007.
Since 2008, these monitors have been sold by Berkeley Air Monitoring Group and are widely used by groups around the world for HAP studies. See examples of publications from studies done in more than a dozen countries.
In 2014, an improved model is expected to become available, the UCB-PATS+. Watch this website and that of Berkeley Air Monitoring Group for an announcement.
We have also developed and tested a bench version of the BAIRS monitor, which relies on a more sophisticated, but still consumer-based, sensor.
- Northcross AL, Edwards RJ, Johnson MA, Wang ZM, Zhu K, Allen T, Smith KR. A low-cost particle counter as a realtime fine-particle mass monitor. Environ. Sci.: Processes Impacts, 2013, 15 433.
A doctoral student in our group, David Holstius, has also developed and tested a related device, the PANDA, which is based on a different sensor.
- Holstius DM, Pillarisetti A, Smith KR, Seto E. Field calibrations of a low-cost aerosol sensor at a regulatory monitoring site in California, Atmos. Meas. Tech., 7, 1121-1131, doi:10.5194/amt-7-1121-2014, 2014.
Stove-Use Monitoring System (SUMS)
We innovated approaches to directly measure the use of stoves by deploying data-logging temperature sensors, which enable much longer, unobtrusive, and accurate monitoring of cooking behavior and “stacking” – use of more than one stove for cooking in a kitchen. Initially, most of our studies have relied on commercial “i-buttons” from the food industry to do the sensing and our contribution has been in placement, data handling, and interpretation. We are also field-testing custom-built sensors; however, including a wireless version from which data can be retrieved without entering the house itself.
Here are our papers describing the idea and initial applications.
- Ruiz-Mercado I, Lam NL, Canuz E, Davila G, Smith KR. (2008) Low-cost temperature loggers as stove use monitors (SUMs). Boiling Point 55:16-19.
- Ruiz-Mercado, I., Masera O, Zamora H, Smith KR (2011). Adoption and sustained use of improved cookstoves. Energy Policy, Volume 39, Issue 12, Pages 7557-7566, ISSN 0301-4215, 10.1016/j.enpol.2011.03.028.
- Ruiz-Mercado I, Canuz E, Smith KR. (2012). Temperature dataloggers as stove use monitors (SUMs): Field methods and signal analysis. Biomass and Bioenergy 47. http://dx.doi.org/10.1016/j.biombioe.2012.09.003
- Ruiz-Mercado I, Canuz E, Walker JL, Smith KR. (2013). Quantitative metrics of stove adoption using Stove Use Monitors (SUMs). Biomass and Bioenergy (2013), http://dx.doi.org/10.1016/j.biombioe.2013.07.002
- Mukhopadhyay R, Sambandam S, Pillarisetti A, Jack D, Mukhopadhyay K, Balakrishnan K, Vaswani M, Bates MN, Kinney PL, Arora N, & Smith, KR. (2012). Cooking practices, air quality, and the acceptability of advanced cookstoves in Haryana, India: an exploratory study to inform large-scale interventions. Global Health Action, 5. doi:10.3402/gha.v5i0.19016
- Pillarisetti, A.; Vaswani, M.; Jack, D.; Balakrishnan, K.; Bates, M. N.; Arora, N. K.; Smith, K. R. Patterns of Stove Usage after Introduction of an Advanced Cookstove: The Long-Term Application of Household Sensors. Environ. Sci. Technol. 2014, 48, 14525–14533.
Berkeley Air Monitoring Group now sells sets of SUMs and associated software for others to use.
With funding through an innovation prize from Vodafone Americas Foundation, we have developed a wireless version of the SUMS, which allows data on stove use to be downloaded unobtrusively without entering the household. It has been field tested in Mexico and India and reports are forthcoming.
Time-activity Monitors (TAMs)
We have developed a simple inexpensive ultrasound-based system for monitoring the amount of time spent by different household members in specific household locations, for example the kitchen. See
- Piccolo-Allen G, Rogers JV, Edwards R, Clark MC, Allen T, Mercado-Ruiz I, Naumoff Shields K, Canuz E, Smith KR (2009). An Ultrasound Personal Locator for Time-Activity Assessment. Internl J Occup and Environ Health 15 (2): 122-132.
Air Exchange Rate Monitors (ARMs)
Our group pioneered the use of carbon monoxide as a tracer gas to measure air exchange rates in village households in the 1980s (Smith, 1987) as an indicator of ventilation. We have now developed a more formal system relying on carbon dioxide as a tracer that allows repetitive measurements under the same conditions in one or many households over time. It is undergoing field testing in Nepal inn 2014. Watch the website for published results.