Vapor intrusion (VI) is a process by which chemicals in soil or

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

- especially

Volatile Organic Compound Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...

s (VOCs) - migrate to indoor air above a contaminated site.

Definition

The

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

defines vapor intrusion as "a migration of volatile chemicals from

groundwater contamination Groundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted ...

contaminated soil Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity ...

into an overlying building". The chemicals can be of different classes including

volatile organic compound Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...

s (VOCs), certain

semi-volatile organic compounds Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...

(SVOCs) and inorganic chemicals, such as elemental mercury,

polycyclic aromatic hydrocarbon A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. ...

s (PAHs), naturally occurring

radon Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through ...

, and

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

Concerns

At worst, vapor intrusion can be a

safety hazard A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probabi ...

, e.g., when flammables are involved in form of an explosion. Noxious vapors can cause

health effect Health effects (or health impacts) are changes in health resulting from exposure to a source. Health effects are an important consideration in many areas, such as hygiene, pollution studies, occupational safety and health, ( utrition and health s ...

s, either acutely such as CNS disturbances like headaches or mental status changes, and they can have chronic health effects, e.g. in the case of radon, which can cause lung cancer. Lastly, vapors can be severe "aesthetic problems", e.g., odors from hydrogen sulfide.

Guidance

In the United States, vapor intrusion is handled in individual states in different ways. Pathbreaking guidance on vapor intrusion was released by the

New York Department of Health The New York State Department of Health (NYSDOH) is the department of the New York state government responsible for public health. It is headed by Health Commissioner Mary T. Bassett, who was appointed by Governor Hochul and confirmed by the S ...

in 2006. In June 2010, the

American Society for Testing and Materials ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...

(ASTM International) released a commercial "Standard Guide for Vapor Encroachment Screening on Property Involved in Real Estate Transactions" (ASTM E 2600–10). In 2002 the US EPA had issued its first draft guidance on the subject . The

George W. Bush Administration George W. Bush's tenure as the 43rd president of the United States began with his first inauguration on January 20, 2001, and ended on January 20, 2009. Bush, a Republican from Texas, took office following a narrow victory over Democratic ...

dropped the project in 2003, and only in 2013 Obama's appointee as EPA Assistant Administrator in the Office of Solid Waste and Emergency Response, made it a priority to complete the document. On June 11, 2015, the EPA released its final ''Vapor Intrusion Technical Guide'', along with a ''Technical Guide for Addressing Petroleum Vapor Intrusion At Leaking Underground Storage Tank Sites''. A guide is neither a statute nor a regulation, but a guidance.

References

Airborne pollutants Air pollution {{Environmental-disaster-stub

Definition

Concerns

Guidance

See also

References