Hydrogen Sulfide Sensing
Hydrogen sulfide, which is a well documented but little understood health hazard, is one of the leading causes of injury in the workplace. Although health issues have been clearly linked with the gas, increasing regulation has been difficult since the oil and gas industries are exempt from many federal laws. Public Lab researchers are attempting to innovate novel community based approaches to environmental health problems like hydrogen sulfide, so that communities and workers may begin not only developing systems to track their exposure, but also generating data and evidence in order to scientifically validate their experiences.
This tool is being developed to detect hydrogen sulfide in an affordable, quantifiable manner. In September of 2011, Public Laboratory members, met with residents of Garfield County, Colorado to discuss the growing hydrogen sulfide problem in their small, rural community. Recently, the community organized to take a gaseous grab sample from one resident’s kitchen sink. Analysis of the grab sample showed hydrogen sulfide levels of more than 185 times above the long-term exposure level recommended by the EPA (Gassed by Global Community Monitoring). The family, in which the son developed painful skin lesions and other symptoms coincident with this exposure, was forced to abandon the house. They are seeking legal assistance, but so far, neighboring gas development companies have denied association with the families water contamination. In this extreme case, the regulatory authorities were not able to act to support exposed individuals. The grab sample, while able to capture one record of exposure, was costly (over $500) and had to be shipped to a lab in California within 24 hours in order to ensure the samples viability. The family did not hear results of the test for weeks, all the while continuing their exposure.
Basic Information on Hydrogen Sulfide
We currently have two approaches to sensing hydrogen sulfide in Development.
First Prototype: Digital Sensor
Our first prototype used a digital sensor for hydrogen sulfide. Advantages of this system is that data from the sensor could be logged over time and that tool is reusable and portable. However the Figaro TGS 825 sensor itself is expensive approximately $60 for an individual sensor and $40 in bulk. (does anyone have a link to buy one online?)
Arduino and Industrial H2S Sensor
Second Prototype: Photographic Paper
Our second prototype uses photographic paper. The silver in photographic paper tarnishes with exposure to hydrogen sulfide. We are working on make a test for hydrogen sulfide using strips of photographic paper. We believe this test could be far more affordable than the digital version and accessible to non-programmers.
Photographic Paper for H2S Sensing
This project is based on these two papers by geologist C. J. Horwell and colleagues that measured hydrogen sulfide concentrations near a volcano in New Zealand.
Horwell, C.J., Allen, A.G., Mather, T.A., Patterson, J.E., 2004. Evaluation of a simple passive sampling technique for monitoring volcanogenic hydrogen sulphide. J. Environ. Monitor. 6, 630 - 635. Horwell_JEM_2004_copy.pdf
Horwell, C.J., Patterson, J.E., Gamble, J.A., Allen, A.G., 2005. Monitoring and mapping of hydrogen sulphide emissions across an active geothermal field: Rotorua, New Zealand. J. Volcanol. Geotherm. Res. 139, 259-269. Horwell_JVGR_2005_copy.pdf
Original photopaper map made by Horwell et. al.
How to make your own
Both of these tools are currently in the early stages of development, research notes can be found at the links below. There are two different tracks, one utilizing an industrial sensor with an arduino board and the other utilizing photographic paper with silver halide based on research done on H2S at volcanoes.
If you are interested in helping develop hydrogen sulfide sensing, please contribute thoughts, comments and research notes on this page as well as join us on the Public Lab mailing list.
- Currently active work on the film assay is being done at Northeastern University by Sara Wylie, Elisabeth Wilder, Deb Thomas, Cait Kennedy, Megan McLaughlin, and Hannah Gartner.
- to successfully sense hydrogen sulfide with photographic paper
- to develop step by step guides to making the tools
- to standardize the photopaper test within laboratory conditions in Louisiana
- to develop open source tools for analyzing the photopaper
- to design a public lab kit
Places to start contributing:
If you're interested in getting involved you could try following the prototype documentation to make your own film testing strips. We can always use help in researching and documenting hydrogen sulfide health issues. Also perhaps you know of site to test or use this tool?
This project is partially funded by a grant from the American Anthropology Association, Anthropology and Environment section