Richard Ha writes:
I met with Tom Travis recently. A Puna resident and former nuclear submarine commander, he is opposed to geothermal in Puna.
Tom is also involved with the strategic public policy consultant group Accord 3.0:
Special Project:
Geothermal Public Health Assessment
ACCORD3.0 is assisting County of Hawaii to convene a reasoned, sustained, and science-focused deliberation on public health questions pertinent to the production of geothermal energy in the Puna region. The project will produce a reliable inventory of studies that address public health concerns surrounding geothermal plants, and develop a set of recommendations about the priorities and preferred methodologies for future scientific and monitoring studies that may be required.
Tom and I talked about common ground, and we both agree that public safety is of the utmost importance.
Shortly after we met, he read the testimony I sent to the Office of Hawaiian Affairs, supporting geothermal energy here in Hawai‘i, and sent me a note saying that my comments about H2S were misleading.
I went back and reviewed the data and he is right. I made an error in saying that the ambient exposure level was 20,000 parts per billion (ppb).
In his comments to me below, he is referring to this study: Associations of ambient hydrogen sulfide exposure with self-reported asthma and asthma symptoms, by Michael N. Bates, Nick Garrett, Julian Crane and John R. Balmes.
Tom wrote:
Figure 1 of the study shows zones of exposure in which the highest gradient line is 50 ppb. Table 2 shows that the highest quarter of study exposures (time weighted average) is 31 to 64 ppb. The study looked at the highest quarter and compared that with those in the other three quarters (Q1=0-10 ppb: Q2=11-20 ppb; and Q3=21-30 ppb). The study found no significant difference in asthma between those in the four quarters.
In the discussion portion there is mention of brief exposures, as quoted below:
“The third area to consider is information bias, particularly with estimates of H2S exposure levels. These were based on data from networks of passive monitors set out during two 2-week periods in 2010, extrapolated to current homes and workplaces. We know, however, from occasional spot measurements that we have made, that in some of the more highly exposed places around Rotorua H2S concentrations may, at least briefly, rise as high as 1 to 2ppm.”
2 ppm is a transient peak exposure and could have been experienced by the study group in any one of the four quarters. If it were experienced by those in the lowest quarter then their comparison with those in the highest quarter would not be valid, assuming that this is the exposure that caused some effect. Therefore, we must assume that Bates believes the time weighted average is what controls the effects on asthma. By the way, 2 ppm is 2000 ppb, not 20000 ppb.
Additionally, as to the implied conclusion that the Bates study says something general about low level health effects, I quote him as follows:
“It is important also to appreciate that H2S is very toxic at higher concentrations and, without appropriate supporting data from exposed populations, no conclusions should be drawn about higher concentrations. That ‘‘hot spots’’ of H2S can occur in Rotorua is well-known and deaths are sometimes attributed to them (Bassindale and Hosking, 2011).
Irrespective of the relationship between H2S and asthma, there are other potential health outcomes from hydrogen sulfide exposure, including possible neurologic and neuropsychologic effects (Kilburn et al., 2010) and effects on the eye, particularly cataract (Bates et al., 2002). These also need to be investigated.”
I’m not pushing an agenda no matter what, or at any cost. My goal is for the well-being of the community, and that’s why I want to be straightforward about my error. I am also writing to OHA to correct my testimony with them.
The goal of Accord 3.0 is to make a fair assessment of all possible health issues related to geothermal here. It’s great that they are doing this.
People are always mixing up the units for H2S levels and I figured out why. Safety levels set by OSHA and other agencies use parts per million (PPM) to define the safety level in discrete numerical steps 1-5, 5-50, 50-100. However, when monitored levels are reported, they are in parts per billion (PPB). This makes total scientific sense since the measuring equipment should have several orders of magnitude precision. The very inexpensive meters that the geothermal haters are against is because they usually max out at 100 PPM. The reason they do that is because these meters are used in industry and if the local level is 100PPM, and you are there without a gas mask or oxygen, you are dead, so the meter is no help. Guess where most of the H2S fatalities occur? In sewers, when unprepared workers encounter a pocket of gas, naturally created by human excrement. These inexpensive meters usually have an accuracy of 10 to 100 PPB, which is either PPM in tenths or hundreths. The safety levels are in gross even numbers because the effects have been well studied and shown the hazard is a logarithmic curve. This is just another feint by the geothermal haters, to extend the general information about H2S as being specific to geothermal, when in reality, H2S hazards exist in many places naturally. There was a recent discovery of the ancient Gateway to Hell in Turkey, where people would die by going into its entrance, which looks fairly evident to be a volcanic vent, no steam but apparently high levels of H2S. Anyway, you made a typo. Off to the Gateway to Hell for you!