VAPOR INTRUSION

VAPOR INTRUSION ~ the ghost hazard

Soils and groundwater contaminated with chlorinated solvents create an “unseen risk” and potential serious hazard to your health. Commonly used by industry and businesses,  chlorinated solvents include PCE (perchloroethylene, also known as 'perc', or tetrachloroethylene) and Trichloroethylene (TCE). These solvents are pervasively used and manmade chemicals. Their typical uses have included dry-cleaning, degreasing and production of plastic linings for drinking water pipes. When these chemicals escape or are released into the environment (soils and groundwater) they can volatilize (turn into vapor) and travel from contaminated groundwater and soil through soil particles and enter our homes and offices where residents breathe the chemicals. These chemicals may cause a myriad health issue (https://wwwn.cdc.gov/TSP/PHS/PHS.aspx?phsid=263&toxid=48 )

Investigators have recently discovered that when testing for the presence of these vaporized contaminates your methods and timing are critical to your receipt of accurate and timely information. (Kram, et al,  Vapor intrusion risk evaluation using automated continuous chemical and physical parameter monitoring) The attached link to Dr. Kram’s Article makes a few key points for those who would like to explore these issue further:

(1)           Sample timing is critical to obtaining the right answer, as samples should be collected while vapor intrusion (VI) is “on” (e.g., upward vapor flow).

(2)           Traditional randomly-timed samples commonly underestimate the risk of exposure because we most often don’t know if VI was “on” during the sample collection campaign.

(3)           USEPA’s Indicator Tracer and Surrogate (ITS) group is focusing on the reasonable maximum exposure (RME), which should be the criteria for all risk-based decisions as recommended by USEPA (2015). More specifically, they aim to improve sample collection timing.

(4)           A few days of continuous monitoring of concentration along with controlling factors (pressure, temp, HVAC, etc.) can yield more appropriate estimates of RME, and therefore provide a better estimate of the risk of human health hazards.

Document attached here: Vapor intrusion risk