From SAFE’s historical archive
November 1, 2012
Peer-reviewed and accepted for publication by Human and Ecological Risk Assessment (November 9, 2012).
Theo Colborn, Kim Schultz, Lucille Herrick, and Carol Kwiatkowski TEDX, The Endocrine Disruption Exchange, Paonia, CO, USA Address correspondence to Carol Kwiatkowski, PhD, Executive Director, TEDX. PO Box 1407, Paonia, CO 81428. Phone and fax: 970 527 4082. Email: carolkw@tds.net.
ABSTRACT
This exploratory study was designed to assess air quality in a rural western Colorado area
where residences and gas wells co-exist. Sampling was conducted before, during, and after
drilling and hydraulic fracturing of a new natural gas well pad. Weekly air sampling for 1 year
revealed that the number of non-methane hydrocarbons (NMHCs) and their concentrations were
highest during the initial drilling phase and did not increase during hydraulic fracturing in this
closed-loop system. Methylene chloride, a toxic solvent not reported in products used in drilling
or hydraulic fracturing, was detected 73% of the time; several times in high concentrations. A
literature search of the health effects of the NMHCs revealed that many had multiple health
effects, including 30 that affect the endocrine system, which is susceptible to chemical impacts at
very low concentrations, far less than government safety standards. Selected polycyclic aromatic
hydrocarbons (PAHs) were at concentrations greater than those at which prenatally exposed
children in urban studies had lower developmental and IQ scores. The human and environmental
health impacts of the NMHCs, which are ozone precursors, should be examined further given
that the natural gas industry is now operating in close proximity to human residences and public
lands.