quarta-feira, 22 de fevereiro de 2012

TEDX — Chemicals in Natural Gas Operations (Fracking)

Source: TEDX (The Endocrine Disruption Exchange, Inc.), http://www.endocrinedisruption.com/chemicals.introduction.php

"As natural gas production rapidly increases across the U.S., its associated pollution has reached the stage where it is contaminating essential life support systems - water, air, and soil - and causing harm to the health of humans, wildlife, domestic animals, and vegetation. This project was designed to explore the health effects of products and chemicals used in drilling, fracturing (frac'ing, or stimulation), recovery and delivery of natural gas. It provides a glimpse at the pattern(s) of possible health hazards posed by the chemicals being used. There are hundreds of products in current use, the components of which are, in many cases, unavailable for public scrutiny and for which we have information only on a small percentage.

Toxic chemicals are used at every stage of development to reach and release the gas. Drilling muds, a combination of toxic and non-toxic substances, are used to drill the well. To facilitate the release of natural gas after drilling, approximately a million or more gallons of fluids, loaded with toxic chemicals, are injected underground under high pressure. This process, called fracturing (fracking or stimulation), uses diesel-powered heavy equipment that runs continuously during the operation. One well can be fracked 10 or more times and there can be up to 28 wells on one well pad. An estimated 30% to 70% of the frac'ing fluid will resurface, bringing back with it toxic substances that are naturally present in underground oil and gas deposits, as well as the chemicals used in the frac'ing fluid. Under some circumstances, nothing is recovered.

Drilling or reserve pits are found on most well pads. They hold used drilling muds, frac'ing fluids and the contaminated water (produced water) which surfaces with the gas. Produced water is found in most regions where gas is extracted and continues to surface for the life of the well (20 to 30 years). It is a common practice to haul it in "water trucks" to large, central evaporation pits. Many of the chemicals found in drilling and evaporation pits are considered hazardous wastes by the Superfund Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Upon closure, every pit has the potential to become a superfund site."

In September, 2011, "Natural Gas Operations from a Public Health Perspective" was published in Human and Ecological Risk Assessment: an International Journal (peer-reviewed), http://www.endocrinedisruption.com/chemicals.journalarticle.php