The "EPA has determined that hydrogen sulfide can reasonably be anticipated to cause serious or irreversible chronic human health effects at relatively low doses and thus is considered to have moderately high to high chronic toxicity....Hydrogen sulfide has also been determined to cause ecotoxicity at relatively low concentrations, and thus is considered to have high ecotoxicity." (Emphasis supplied.)

(Additional links: PDF copy and 76 FR 64027.)

Study funded by the County of Hawai`i recommending a comprehensive health study of geothermal related effects. "Risks from geothermal energy production in Lower Puna exist. The actual extent and impacts of those risks remains unresolved. What is known is that hazardous chemicals are brought up by PGV. PGV adds industrial chemicals to the mix in the process and then sends the composite fluid back down. However, fluids inevitably escape to air, water, or at surface level. Harmful effects can only be understood through better monitoring and reliable health data."

9 page pdf document, Marvin S. Legator et al, 2001: "In this study, the authors compared symptoms of adverse health effects, reported by residents of two communities exposed mainly to chronic, low-levels of industrial sources of hydrogen sulfide...."

2 page pdf document, Marvin S. Legator and Chantele R. Singleton, 1997: "...public health officials and the scientific establishment have often been ineffective and unsympathetic in their efforts to aid communities exposed to toxic chemicals..."

20 page pdf document, Kaye H Kilburn et al, 2010, "The precautionary principle recommends that smelling this gas is a warning that should be heeded by people to evacuate quickly."

9 page pdf document, Kaye S. Kilburn, MD, 2001: "Nineteen hydrogen sulfide (H2S)-exposed patients
were compared with 202 unexposed subjects."

250 page pdf report on cumulative health effects of repeated low-level H2S exposure by the Science and Standards Branch of Alberta Environment, Canada: "background information on hydrogen sulphide ... identify[ing] knowledge gaps about the health effects of hydrogen sulphide and may be useful in designing future research projects...."

77 page pdf document providing a micrometeorological aerometric analysis of a Puna Geothermal Venture (PGV) injection well's uncontrolled venting starting on June 12 and ending on June 14, 1991 (by Goddard and Goddard Engineering)

Article from the Houston Chronicle Archives, Jim Morris,11/09/1997:  "Some residents of the lush and eclectic Puna District are convinced that hydrogen sulfide escaping from the PGV well field and power plant is making them ill."

64 page pdf report by Environmental Protection Agency (EPA) summarizing a review of emergency response capabilities for Hawai’i County and Puna Geothermal Venture (PGV)

15 page pdf essay by Noa Emmett Aluli, M.D. and Davianna Pomaika'i McGregor, PhD, titled 'Aina: Ke Ola O Na Kanaka 'Oiwi (Land: The Health of Native Hawaiians.) 

This is one of the first studies to show that exposure to low levels of hydrogen sulfide is associated with poor respiratory health, as shown by the number of people filling asthma medications in the days that follow. Prior studies with workers receiving higher exposures to the gas have shown mainly neurologic effects.

H₂S Safety Factsheet, August 2004

H2S is classed as a chemical asphyxiant, similar to carbon monoxide and cyanide gases. It inhibits cellular respiration and uptake of oxygen, causing biochemical suffocation.  Prolonged exposures at lower levels can lead to bronchitis, pneumonia, migraine headaches, pulmonary edema, and loss of motor coordination

Data on EPA's Integrated Risk Information System for hydrogen sulfide

Environ Health Perspect. 2008 January; 116(1): 78–85: "Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S)." (additional link: http://www.ncbi.nlm.nih.gov/pubmed/18197303)

69 page PDF document from Lawrence Livermore National Lab (1981): "Several of the important health and environmental risks associated with a reference geothermal industry ... are assessed. The analyses of health effects focus on the risks associated with exposure to hydrogen sulfide, particulate sulfate, benzene, mercury, and radon in air and arsenic in water...."

Prolonged exposures at lower levels can lead to bronchitis, pneumonia, migraine headaches, pulmonary edema, and loss of motor coordination.
Hydrogen sulfide (H2S, CAS# 7783-06-4) is an extremely hazardous, toxic compound. It is a colourless, flammable gas that can be identified in relatively low concentrations, by a characteristic rotten egg odor.

92 page pdf document (takes a long time to load) prepared October 12, 1984, by the State Department of Health (DOH). Residents in Puna have expressed considerable concern that hydrogen sulfide (H2S) and other effluents released by the HGP-A well and other geothermal development projects may adversely affect their health and quality of life. Little concern was publicly voiced about H2S and other potentially toxic gases naturally vented in the area prior to the drilling of these wells. 

This 1984 DOH report said "It could not be determined that H2S produced as a result of geothermal development in the area was responsible for any of the health conditions reported in Leilani Estates. Further studies are required to determine what factors account for the relatively high rates of chronic respiratory conditions reported in the areas surveyed in Puna when compared to average State-wide and County-wide rates."  Studies since 1984 demonstrating toxic and adverse impacts from chronic exposure to low levels of H2S are listed in this section.

Hazardous Substance Fact Sheet on Pentane (according to Mike Kalekini, PGV keeps between 59,000 and 62,000 gallons of Isopentane on-site for use in producing eectricity)

This is what PGV uses and they have 62,000 gallons on site. The lose 40 gallons a day into the environment.....