Russian roulette in the shale patch II – Oil and gas workers exposed to hazardous chemicals | Tanja Srebotnjak’s Blog | Switchboard, from NRDC

Russian roulette in the shale patch II – Oil and gas workers exposed to hazardous chemicals | Tanja Srebotnjak’s Blog | Switchboard, from NRDC.

 

This is part two in a three-part series on the occupational health and safety risks of workers in the booming oil and gas industry.

The expansion in U.S. oil and gas production due to advances in horizontal drilling techniques and controversial well stimulation methods such as hydraulic fracturing (‘fracking’) and acidizing has spurred job growth in the nation’s oil and gas fields. But, oil and gas exploration and production is a dirty, difficult, and dangerous field of work – every process stage, piece of equipment, and the produced hydrocarbons themselves represent a source of pollutants and a health and safety risk to workers [1,2].

According to the Bureau of Labor Statistics (BLS), direct employment in the oil and gas extraction sector (NAICS code 211) grew steadily from 125,000 in September 2004 to more than 213,000 in September 2014. Adding in associated industries the number swells to 562,000 (2012) this is a significant workforce doing risky jobs with inadequate protections.

While my previous blog discussed how dangerous the industry can be in terms of fatal accidents, this blog considers the potential exposure of oil and gas field workers to hazardous chemicals and substances.

A recent study conducted by the National Institute for Occupational Safety and Health (NIOSH) found alarmingly high chemical exposure for workers at oil and gas sites [3]. The researchers took personal breathing zone samples of workers engaged in tasks such as checking fluid levels in flowback and production tanks, operating pumps, hauling water, and changing chokes and filters on water tanks and other equipment.  Among the many volatile chemicals associated with flowback operations, benzene was found to be the primary exposure hazard for the workers. Benzene is a known carcinogen with additional adverse health effects on the blood and immune systems. Fifteen of the 17 samples taken met or exceeded the NIOSH Recommended Exposure Level (REL) of 0.1ppm for a full-shift time-weighted average exposure. The inhalation risks were highest for workers operating in close proximity to the hatches of the flowback and production tanks and during tasks involving gauging tank levels. However, measured concentrations were also high downwind of these emission sources and in a tent used by workers during their break times.

Other Air Toxics and Chemicals of Concern

Numerous air quality studies near oil and gas sites have identified aromatic petroleum hydrocarbons such as benzene, toluene, ethylbenzene, and xylene (BTEX); aliphatic hydrocarbons; alcohols; aldehydes; combustion products (diesel particulates, nitrogen oxides); and hydrogen sulfide (H2S). In addition to breathing in these volatile compounds, chemical handling, fluid preparation, disposal, and transport all present routes of exposure to harmful substances. Many of the chemicals have acute and long-term adverse health effects, even at low concentrations, as shown in the table. In addition, even if the concentrations of individual chemicals may be below health-protective standards, their cumulative health effects may be significant [4].

Chemical / Compound

Process stages

Health Effects

BTEX

       Benzene

Well site preparation, drilling and completion, production, processing, transmission

Cancer (leukemias, non-Hodgkin lymphoma); blood and immune system disorders

       Toluene

Brain and nervous system depression; Respiratory effects; Fetal and developmental disorders

       Ethylbenzene

Fetal and developmental disorders; Endocrine disruption; kidney and liver damage

       Xylene

Brain and nervous system depression; Fetal and developmental disorders

PAH (incl. Naphthalene, Chlorobenzene, Phenol)

Well site preparation, drilling and completion, production, processing, transmission

Cancer; fetal and developmental disorders; Inflammation of the respiratory system and worsening of asthma and COPD; Damage to the cardiovascular, brain and nervous systems; Impairment of the digestive system, kidneys, and reproductive system

Other VOCs (incl. Formaldehyde, Ethylene glycol, Methanol)

Well drilling and completion, production, and processing

Cancer; immune system disorders; Respiratory system inflammation and worsening of asthma and COPD symptoms; Brain and nervous system depression; Fetal and developmental disorders; Disruption of normal liver, kidney and endocrine system function

Hydrogen Sulfide (H2S)

Well drilling and completion, production, and processing

Acute nervous system toxicity; Death; long-term effects include headaches, poor attention span, loss of memory and motor function

Diesel particulate matter

Well site preparation, drilling and completion, production, processing, transmission

Cancer (lung cancer); respiratory effects, including worsening of asthma and COPD symptoms

Hydrofluoric acid

Acidizing, fracking

Strongly corrosive; damage to muscle and nerve tissue; cardiac arrest; death

Sodium hydroxide

Fracking

Tissue burns; Irritating to the eyes, nose, throat, and lungs

Sources: ATSDR, Public Health Statements on benzene, toluene, ethylbenzene, and xylenes, www.atsdr.cdc.gov/substances/index.asp (accessed October 22, 2014). OSHA, “Safety and Health Topics: Hydrogen Sulfide,”www.osha.gov/SLTC/hydrogensulfide/standards.html (accessed October 22, 2014). OSHA, “Safety and Health Topics: Diesel Exhaust,” www.osha.gov/SLTC/dieselexhaust/(accessed October 22, 2014). ATSDR, “Public Health Statement for Polycyclic Aromatic Hydrocarbons,” www.atsdr.cdc.gov/phs/phs.asp?id=120&tid=25 (accessed October 22, 2014). ATSDR, “Public Health Statement for Hydrogen Fluoride,”www.atsdr.cdc.gov/MMG/MMG.asp?id=1142&tid=250 (accessed October 22, 2014). OSHA, “Sodium Hydroxide,” www.osha.gov/dts/chemicalsampling/data/CH_267700.html(accessed October 22, 2014).

 

Actions to be taken

In light of the available evidence, several measures should be taken to address information gaps and reduce worker exposure to benzene and other hazardous air pollutants, including:

  • Conducting health hazard and risk evaluations of workers at oil and gas production sites during all stages of well preparation, drilling and completion, production, processing and distribution to determine the potential for worker exposure
  • Implementing effective engineering, administrative, and training protocols and procedures to reduce worker exposure such as developing alternative methods for tank fluid level gauging, occupational safety training, altering work procedures to reduce the time spent in proximity to emission sources, and use of personal monitoring and protection devices
  • Increasing well site inspection and enforcement actions for violations of occupational safety and health standards

The current energy boom is generating new jobs from Pennsylvania to California, but they should not jeopardize workers’ health and safety.

References

[1] John L. Adgate, Bernard D. Goldstein, Lisa M. McKenzie, “Potential Public Health Hazards, Exposures and Health Effects from Unconventional Natural Gas Development,”Environmental Science & Technology, February, 2014, doi:10.1021/es404621d.

[2] Christopher W. Moore, Barbara Zielinska, Gabrielle Pétron, Robert B. Jackson, “Air Impacts of Increased Natural Gas Acquisition, Processing, and Use: A Critical Review,”Environmental Science & Technology, 11 (2014), doi:dx.doi.org/10.1021/es4053472.

[3] Eric J. Esswein, et al. “Evaluation of Some Potential Chemical Exposure Risks During Flowback Operations in Unconventional Oil and Gas Extraction: Preliminary Results,”Journal of Occupational and Environmental Hygiene 11: D174–84 (2014), doi:10.1080/15459624.2014.933960.

[4] Roxana Z. Witter, et al., “Occupational Exposures in the Oil and Gas Extraction Industry: State of the Science and Research Recommendations,” American Journal of Industrial Medicine, March 2014, doi:10.1002/ajim.22316.