It is now recognised that the exploration and extraction of natural gas (methane) and oil from conventional and non-conventional sources poses many potential direct and indirect risks to human health and wellbeing. As recently as 2013, there were few peer-reviewed publications available in the health science literature upon which to assess the potential local, regional and global health related impacts associated with these industries. Over the last six years, however, public health and environmental science researchers and doctors have published over 1500 papers, with a substantial body of research findings, mainly from the United States where rapid and expansive development of gas and oil fields has occurred in close proximity to residential areas.
This paper presents a comprehensive review process that has been ongoing among Doctors for the Environment Australia’s (DEA) unconventional gas group since 2013. It is informed by literature searches on PubMed, Scopus and the ROGER (Repository of Oil and Gas Energy Research) database, which have enabled DEA to make many evidence-based submissions to governments on the health implications of gas development proposals across Australia.
Of particular concern is the clear evidence of the substantial and rising greenhouse gas footprint of the expanding gas and oil industry that threatens global efforts to urgently reduce emissions. This is often underestimated through:
- Failure to consider the footprint of the entire lifecycle of gas production, transport and use;
- Underestimation of the quantity and duration of fugitive methane emissions;
- Inappropriate application of climate-forcing potency of methane over a 100 year time timeframe (20 times more than CO2), rather than the more appropriate 20 year timeframe (86 times higher potency) given the already measurable health impacts of current rapid warming;
- Failure to consider the potential significance of large scale methane-emitting accidents (e.g. Aliso Canyon storage facility in California) and leakages that are difficult to stop quickly;
- Failure to incorporate the negative political influences and economic competition between abundant gas from large expansions and low emission renewable energies in the energy market.
In addition to greenhouse gas emissions, a second major concern to health associated with gas mining is the wide array of chemicals used in drilling and hydraulic fracturing, and released into the environment through airborne emissions and wastewater, and emitted from the high level of industrial activity (e.g. compressor stations, gas processing plants, on-site diesel-powered machinery and heavy vehicles) surrounding the production process.
Potential chemicals of concern within shale and coal seam gas mining wastewater include volatile organic compounds notably benzene, phenols, polyaromatic hydrocarbons, heavy metals, salt and technologically enhanced naturally occurring radioactive materials that may become concentrated through treatment processes.
Studies examining the potential toxicities of chemicals found in shale gas wastewater have reported that many have not been evaluated, including known carcinogens and/or have the potential for endocrine disruption, and neurological, reproductive and developmental harm.
Many studies report evidence of pathways through which ground and surface water can, and in some cases has, been impacted by gas well activity, through spillage, injection procedures, spills or deliberate discharge of inadequately treated water, leakage from wastewater pits and ponds.
Potentially harmful substances emitted into the atmosphere during dewatering, gas production and processing, waste water handling and transport include PM2.5 and PM10, volatile organic compounds, hydrogen sulphide, formaldehyde, diesel exhaust and ground level ozone. Measuring concentrations and human exposures to these pollutants is complicated as levels vary widely over time and location, making it difficult to directly link airborne exposures to health impacts.
The review also found accumulating evidence of associations between residence close to gas mining activities and reports of poorer health such as asthma, sinus and migraines, skin rashes, headaches as well as hospitalisations for heart, neurological, respiratory, immune system diseases and some cancers. While most of these studies have been conducted in the US, exploratory hospital-based studies suggest that similar trends may be emerging between regions with and without coal seam gas mining in Queensland, Australia.
Increasingly consistent observations of higher frequencies of negative birth outcomes, such as low birth weight, extreme pre-term delivery, higher risk births and some birth defects, have been reported to occur in pregnancies spent close (within 3 km) to gas mining activities, compared to pregnancies spent further away, or in the same area before commencement of gas mining activities.
Increased levels of stress, depression and sexually transmitted infections, aggression, criminal activity and traffic accidents have also been reported among those living near gas mining, likely reflecting psychological and social disturbance among individuals and whole communities. Australian researchers have found that stress and worries about coal seam gas mining may contribute significantly to mental health risks among directly affected farmers.
Of particular concern to Australian agriculture and remote communities is research showing an unpredicted but consistent rise in water footprint – up to 7.7 and 14 fold increases in water usage and waste used per well in semi-arid regions across the United States.
In summary, the review found growing evidence of direct health impacts as well as a clear potential for indirect impacts of gas and oil mining on essential environmental determinants of health, including a stable climate, air quality, water quality, water security, food security, community cohesion and, in some locations, geological stability. The cumulative impacts of these industries on the wider requirements for good health and wellbeing are extremely concerning.
At a time when the dangers of climate change are becoming readily apparent through record-breaking heat waves, droughts, floods, forest fires and cyclones and increasing food and water security concerns, accelerating new and expanding existing gas developments is counterproductive to reducing greenhouse gas emissions. It is not possible to overemphasise the enormity of health, economic, security and environmental costs of an inadequate response to global warming.
Doctors for the Environment Australia urge the Australian government to commit to a national energy plan that prioritises the urgency of climate change. Accordingly DEA urges a ban on new gas and oil developments, and heavy regulation of existing gas developments while vigorously promoting a coordinated transition to renewable energy.