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57-528: It was built out of a portion of the decommissioned Wurtsmith Air Force Base which housed nuclear armed B-52 Stratofortress bombers during the Cold War as well as air refueling squadrons. Oscoda–Wurtsmith Airport became a public airport in 1993. It is primarily a large jet airplane salvage, jet engine maintenance and light general aviation airport with no scheduled passenger or cargo services. The Wurtsmith Base Conversion Authority terminated in 1994, when

114-455: A fixed-base operator that offers aviation fuel – both avgas and jet fuel – and amenities such as general maintenance , catering , courtesy transportation, a crew lounge, and more. For the 12-month period ending December 31, 2021, the airport had 5,668 aircraft operations, an average of 109 per week. At the same time, there were 37 aircraft based on the airport: 19 jet aircraft , 17 single-engine airplanes , and 1 helicopter . Of note

171-451: A PAH that was subsequently demonstrated to cause tumors . Cook, Hewett and Hieger then linked the specific spectroscopic fluorescent profile of benzo[ a ]pyrene to that of the carcinogenic component of coal tar, the first time that a specific compound from an environmental mixture (coal tar) was demonstrated to be carcinogenic. In the 1930s and later, epidemiologists from Japan, the UK, and

228-726: A former fire training area on the base. Air Force completed the PFAS Preliminary Assessment, Site Inspection, and planned the Remedial Investigation under the Comprehensive Environmental Response, Compensation, and Liability Act . Air Force performed three removal actions and planned two interim remedial actions . On November 1, 2017, more than twenty-two years after being listed as a superfundsite Wurtsmith held its first Restoration Advisory Board meeting. During

285-636: A primary human health risk of exposure to PAHs. Exposure to PAHs has also been linked with cardiovascular disease and poor fetal development. PAHs have been linked to skin , lung , bladder , liver , and stomach cancers in well-established animal model studies. Specific compounds classified by various agencies as possible or probable human carcinogens are identified in the section " Regulation and Oversight " below. Historically, PAHs contributed substantially to our understanding of adverse health effects from exposures to environmental contaminants , including chemical carcinogenesis . In 1775, Percivall Pott ,

342-1317: A substantial outdoor source of PAHs in particulate air pollution. Geographically, major roadways are thus sources of PAHs, which may distribute in the atmosphere or deposit nearby. Catalytic converters are estimated to reduce PAH emissions from gasoline-fired vehicles by 25-fold. People can also be occupationally exposed during work that involves fossil fuels or their derivatives, wood-burning, carbon electrodes , or exposure to diesel exhaust . Industrial activity that can produce and distribute PAHs includes aluminum , iron , and steel manufacturing; coal gasification , tar distillation, shale oil extraction ; production of coke , creosote , carbon black , and calcium carbide ; road paving and asphalt manufacturing; rubber tire production; manufacturing or use of metal working fluids; and activity of coal or natural gas power stations . PAHs typically disperse from urban and suburban non-point sources through road runoff , sewage , and atmospheric circulation and subsequent deposition of particulate air pollution. Soil and river sediment near industrial sites such as creosote manufacturing facilities can be highly contaminated with PAHs. Oil spills , creosote, coal mining dust, and other fossil fuel sources can also distribute PAHs in

399-504: A surgeon at St. Bartholomew's Hospital in London, observed that scrotal cancer was unusually common in chimney sweepers and proposed the cause as occupational exposure to soot . A century later, Richard von Volkmann reported increased skin cancers in workers of the coal tar industry of Germany, and by the early 1900s increased rates of cancer from exposure to soot and coal tar was widely accepted. In 1915, Yamigawa and Ichicawa were

456-427: A variety of factors including proximity to municipal and industrial discharge points, wind direction and distance from major urban roadways, as well as tidal regime which controls the diluting effect of generally cleaner marine sediments relative to freshwater discharge. Consequently, the concentrations of pollutants in estuaries tends to decrease at the river mouth. Understanding of sediment hosted PAHs in estuaries

513-619: 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 . PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are found in coal and in oil deposits, and are also produced by the incomplete combustion of organic matter —for example, in engines and incinerators or when biomass burns in forest fires . Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by

570-408: Is a consequence of the fact that the σ-bonds that result from the merger of sp hybrid orbitals of adjacent carbons lie on the same plane as the carbon atom. Those compounds are achiral , since the plane of the molecule is a symmetry plane. In rare cases, PAHs are not planar. In some cases, the non-planarity may be forced by the topology of the molecule and the stiffness (in length and angle) of

627-577: Is a decommissioned United States Air Force base in Iosco County, Michigan . Near Lake Huron , it operated for seventy years, from 1923 until decommissioned in 1993. On January 18, 1994, Wurtsmith was listed as a Superfund site, due to extensive groundwater contamination with heavy metals, polycyclic aromatic hydrocarbons, volatile organic compounds , including trichloroethylene , 1,1-dichloroethane, 1,1,1-trichloroethane, and vinyl chloride . In 2010, Per- and polyfluoroalkyl substances contamination

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684-602: Is greater (each has a sextet in two of the three Clar structures) compared to the inner rings (each has a sextet in only one of the three). PAHs are nonpolar and lipophilic . Larger PAHs are generally insoluble in water, although some smaller PAHs are soluble. The larger members are also poorly soluble in organic solvents and in lipids . The larger members, e.g. perylene, are strongly colored. Polycyclic aromatic compounds characteristically yield radicals and anions upon treatment with alkali metals. The large PAH form dianions as well. The redox potential correlates with

741-555: Is important for the protection of commercial fisheries (such as mussels ) and general environmental habitat conservation because PAHs can impact the health of suspension and sediment feeding organism. River-estuary surface sediments in the UK tend to have a lower PAH content than sediments buried 10–60 cm from the surface reflecting lower present day industrial activity combined with improvement in environmental legislation of PAH. Typical PAH concentrations in UK estuaries range from about 19 to 16,163 µg/kg (dry sediment weight) in

798-720: Is low. Lower-temperature combustion, such as tobacco smoking or wood-burning , tends to generate low molecular weight PAHs, whereas high-temperature industrial processes typically generate PAHs with higher molecular weights. Incense is also a source. PAHs are typically found as complex mixtures. PAHs may result from the incomplete combustion of organic matter in natural wildfires . Substantially higher outdoor air, soil, and water concentrations of PAHs have been measured in Asia, Africa, and Latin America than in Europe, Australia,

855-472: Is reversed as the lower molecular weight PAHs are attenuated by biotic decay and photodegradation . Evaluation of the PAH distributions using statistical methods such as principal component analyses (PCA) enabled the study to link the source (burnt moorland) to pathway (suspended stream sediment) to the depositional sink (reservoir bed). Concentrations of PAHs in river and estuarine sediments vary according to

912-567: Is the operations of the Yankee Air Force Museum – Wurtsmith Division. It holds periodic events. Kalitta Air has a large maintenance operation at the airport. Other tenants at the former base include the Aune Medical Center, Alcona Health Center Dental Clinic, Alpena Community College , Comprehensive Aviation Training, and numerous private businesses. The former military housing units have been refurbished by

969-808: The COVID-19 pandemic , Wurtsmith Restoration Advisory Board (RAB) meetings became virtual events, yet in August 2021 RAB members said that progress was made on the WAFB cleanup, and that the relationship between the Air Force and the community has improved. [REDACTED]  This article incorporates public domain material from the Air Force Historical Research Agency 44°27′09″N 83°22′49″W  /  44.4525°N 83.380278°W  / 44.4525; -83.380278 Polycyclic aromatic hydrocarbon A polycyclic aromatic hydrocarbon ( PAH )

1026-745: The Charter Township of Oscoda took over as the Redevelopment Authority. The Authority was organized under Michigan Public Act 206 of 1957. It has five municipal constituents; Oscoda Township, AuSable Township, Greenbush Township, Iosco County and Alcona County. The purpose of the Authority is generally to operate and maintain a public airport. The Michigan Legislature created the Wurtsmith Renaissance Zone in 1997, which exempted businesses and residents of

1083-507: The Cretaceous-Tertiary (K-T) boundary , more than 100 times the level in adjacent layers. The spike was attributed to massive fires that consumed about 20% of the terrestrial above-ground biomass in a very short time. PAHs are prevalent in the interstellar medium (ISM) of galaxies in both the nearby and distant Universe and make up a dominant emission mechanism in the mid-infrared wavelength range, containing as much as 10% of

1140-520: The River Clyde and 626 to 3,766 µg/kg in the River Mersey . In general estuarine sediments with a higher natural total organic carbon content (TOC) tend to accumulate PAHs due to high sorption capacity of organic matter. A similar correspondence between PAHs and TOC has also been observed in the sediments of tropical mangroves located on the coast of southern China. Cancer is

1197-483: The earliest forms of life . The terms polyaromatic hydrocarbon , or polynuclear aromatic hydrocarbon (abbreviated as PNA) are also used for this concept. By definition, polycyclic aromatic hydrocarbons have multiple aromatic rings, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC , consider naphthalene to be the simplest PAH. Other authors consider PAHs to start with

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1254-472: The ocean can be a substantial sink for PAHs. Algae and some invertebrates such as protozoans , mollusks , and many polychaetes have limited ability to metabolize PAHs and bioaccumulate disproportionate concentrations of PAHs in their tissues; however, PAH metabolism can vary substantially across invertebrate species. Most vertebrates metabolize and excrete PAHs relatively rapidly. Tissue concentrations of PAHs do not increase ( biomagnify ) from

1311-544: The 5,000 acre (20 km²) zone from all state and most local taxes. It now occupies a portion of the former base and is primarily used for cargo and light general aviation activities. The airport offers 24-hour near all weather daily access. Its UNICOM frequency is 123.0 MHz. Oscoda–Wurtsmith Airport covers an area of 2,000 acres (810  ha ) at an elevation of 634 feet (193 m) above mean sea level . It has one asphalt paved runway designated 7/25 which measures 11,800 by 200 feet (3,597 by 61 m). The airport has

1368-658: The DNA sequence is altered in genes that regulate cell replication , cancer can result. Mutagenic PAHs, such as benzo[ a ]pyrene, usually have four or more aromatic rings as well as a "bay region", a structural pocket that increases reactivity of the molecule to the metabolizing enzymes. Mutagenic metabolites of PAHs include diol epoxides, quinones , and radical PAH cations . These metabolites can bind to DNA at specific sites, forming bulky complexes called DNA adducts that can be stable or unstable. Stable adducts may lead to DNA replication errors, while unstable adducts react with

1425-459: The DNA strand, removing a purine base (either adenine or guanine ). Such mutations, if they are not repaired, can transform genes encoding for normal cell signaling proteins into cancer-causing oncogenes . Quinones can also repeatedly generate reactive oxygen species that may independently damage DNA. Enzymes in the cytochrome family ( CYP1A1 , CYP1A2 , CYP1B1 ) metabolize PAHs to diol epoxides. PAH exposure can increase production of

1482-510: The U.S., and Canada. Polycyclic aromatic hydrocarbons are primarily found in natural sources such as bitumen . PAHs can also be produced geologically when organic sediments are chemically transformed into fossil fuels such as oil and coal . The rare minerals idrialite , curtisite , and carpathite consist almost entirely of PAHs that originated from such sediments, that were extracted, processed, separated, and deposited by very hot fluids. High levels of such PAHs have been detected in

1539-709: The US, including Richard Doll and various others, reported greater rates of death from lung cancer following occupational exposure to PAH-rich environments among workers in coke ovens and coal carbonization and gasification processes. The structure of a PAH influences whether and how the individual compound is carcinogenic. Some carcinogenic PAHs are genotoxic and induce mutations that initiate cancer; others are not genotoxic and instead affect cancer promotion or progression. PAHs that affect cancer initiation are typically first chemically modified by enzymes into metabolites that react with DNA, leading to mutations. When

1596-573: The United States. A year-long sampling campaign in Athens, Greece found a third (31%) of PAH urban air pollution to be caused by wood-burning, like diesel and oil (33%) and gasoline (29%). It also found that wood-burning is responsible for nearly half (43%) of annual PAH cancer-risk ( carcinogenic potential) compared to the other sources and that wintertime PAH levels were 7 times higher than in other seasons, especially if atmospheric dispersion

1653-530: The Village of Oscoda, and now serve as a major population base in the Oscoda area. Another portion of the former base houses a community center. The Michigan Aerospace Manufacturers Association announced that Chippewa County, Michigan will house its new command and control center. This is the third major announcement from the organization — guiding Michigan’s aerospace and defense manufacturing community within

1710-674: The airport. It will be a part of a larger operation involving other tops at Grayling , Traverse City , and Oscoda . On 18 January 1994, the Environmental Protection Agency proposed to add Wurtsmith Air Force Base to the National Priorities List making the base a Superfund site. Discovery of groundwater contaminated with metals, polycyclic aromatic hydrocarbons , and volatile organic compounds , including trichloroethylene , 1,1-dichloroethane , 1,1,1-trichloroethane , and vinyl chloridebon

1767-633: The atmosphere and the top layers of surface waters can produce nitrogenated, halogenated, hydroxylated, and oxygenated PAHs; some of these compounds can be more toxic, water-soluble, and mobile than their parent PAHs. The British Geological Survey reported the amount and distribution of PAH compounds including parent and alkylated forms in urban soils at 76 locations in Greater London . The study showed that parent (16 PAH) content ranged from 4 to 67 mg/kg (dry soil weight) and an average PAH concentration of 18 mg/kg (dry soil weight) whereas

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1824-455: The atmosphere predominantly in gaseous form, although the physical state of four-ring PAHs can depend on temperature. In contrast, compounds with five or more rings have low solubility in water and low volatility; they are therefore predominantly in solid state , bound to particulate air pollution , soils , or sediments . In solid state, these compounds are less accessible for biological uptake or degradation, increasing their persistence in

1881-487: The base drove the proposal. Knowledge of the contaminated soil and groundwater existed since 1977, and cleanup efforts began before the Superfund program was created. In 1999 and 2001, Soil vapor extraction systems were added to remove the volatile organic compounds from the site. Since 2004, bioventing and biosparging systems have been cleaning soil and groundwater. Wurtsmith was proposed but never formally added to

1938-444: The carbon skeleton, may be distorted by repulsion or steric hindrance between the hydrogen atoms in their periphery. Benzo[c]phenanthrene, with four rings fused in a "C" shape, has a slight helical distortion due to repulsion between the closest pair of hydrogen atoms in the two extremal rings. This effect also causes distortion of picene. Adding another benzene ring to form dibenzo[c,g]phenanthrene creates steric hindrance between

1995-664: The carbon-carbon bonds. For example, unlike coronene , corannulene adopts a bowl shape in order to reduce the bond stress. The two possible configurations, concave and convex, are separated by a relatively low energy barrier (about 11 kcal / mol ). In theory, there are 51 structural isomers of coronene that have six fused benzene rings in a cyclic sequence, with two edge carbons shared between successive rings. All of them must be non-planar and have considerable higher bonding energy (computed to be at least 130 kcal/mol) than coronene; and, as of 2002, none of them had been synthesized. Other PAHs that might seem to be planar, considering only

2052-441: The central ring is less aromatic and therefore more reactive. In contrast, in anthracene the resonance structures have one sextet each, which can be at any of the three rings, and the aromaticity spreads out more evenly across the whole molecule. This difference in number of sextets is reflected in the differing ultraviolet–visible spectra of these two isomers, as higher Clar pi-sextets are associated with larger HOMO-LUMO gaps;

2109-508: The distant universe. In June 2013, PAHs were detected in the upper atmosphere of Titan , the largest moon of the planet Saturn . Volcanic eruptions may emit PAHs. Certain PAHs such as perylene can also be generated in anaerobic sediments from existing organic material, although it remains undetermined whether abiotic or microbial processes drive their production. Most PAHs are insoluble in water, which limits their mobility in

2166-408: The environment, although PAHs sorb to fine-grained organic-rich sediments . Aqueous solubility of PAHs decreases approximately logarithmically as molecular mass increases. Two-ringed PAHs, and to a lesser extent three-ringed PAHs, dissolve in water, making them more available for biological uptake and degradation . Further, two- to four-ringed PAHs volatilize sufficiently to appear in

2223-656: The environment. Human exposure varies across the globe and depends on factors such as smoking rates, fuel types in cooking, and pollution controls on power plants, industrial processes, and vehicles. Developed countries with stricter air and water pollution controls, cleaner sources of cooking (i.e., gas and electricity vs. coal or biofuels), and prohibitions of public smoking tend to have lower levels of PAH exposure, while developing and undeveloped countries tend to have higher levels. Surgical smoke plumes have been proven to contain PAHs in several independent research studies. Burning solid fuels such as coal and biofuels in

2280-436: The environment. Two- and three-ringed PAHs can disperse widely while dissolved in water or as gases in the atmosphere, while PAHs with higher molecular weights can disperse locally or regionally adhered to particulate matter that is suspended in air or water until the particles land or settle out of the water column . PAHs have a strong affinity for organic carbon , and thus highly organic sediments in rivers , lakes , and

2337-412: The federal Superfund program. In 2010, PFC contamination was discovered. There is a "do not eat" advisory for all non-migratory fish caught from Clark's Marsh and the lower Au Sable River south of the former base. Wurtsmith is one of 200 military installations around the world that did or still use PFC-laden Aqueous Film Forming Foam (AFFF). Wurtsmith Air Force Base Wurtsmith Air Force Base

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2394-410: The first to experimentally produce cancers, specifically of the skin, by topically applying coal tar to rabbit ears. In 1922, Ernest Kennaway determined that the carcinogenic component of coal tar mixtures was an organic compound consisting of only carbon and hydrogen. This component was later linked to a characteristic fluorescent pattern that was similar but not identical to benz[ a ]anthracene ,

2451-511: The global industry. Previously, MAMA announced plans for a Oscoda, Michigan Wurtsmith Airport horizontal launch site at and a Marquette, Michigan vertical launch site. The airport also has a hot pit for the Michigan Air National Guard to allow aircraft to restock and resupply without shutting their engines off. The Air National Guard will supply its own fuel, and the entire project will run at little to no cost to

2508-407: The highest-wavelength absorbance of phenanthrene is at 293 nm, while anthracene is at 374 nm. Three Clar structures with two sextets each are present in the four-ring chrysene structure: one having sextets in the first and third rings, one in the second and fourth rings, and one in the first and fourth rings. Superposition of these structures reveals that the aromaticity in the outer rings

2565-482: The home for cooking and heating is a dominant global source of PAH emissions that in developing countries leads to high levels of exposure to indoor particulate air pollution containing PAHs, particularly for women and children who spend more time in the home or cooking. In industrial countries, people who smoke tobacco products, or who are exposed to second-hand smoke , are among the most highly exposed groups; tobacco smoke contributes to 90% of indoor PAH levels in

2622-516: The homes of smokers. For the general population in developed countries, the diet is otherwise the dominant source of PAH exposure, particularly from smoking or grilling meat or consuming PAHs deposited on plant foods, especially broad-leafed vegetables, during growth. Exposure also occurs through drinking alcohol aged in charred barrels, flavored with peat smoke, or made with roasted grains. PAHs are typically at low concentrations in drinking water. Emissions from vehicles such as cars and trucks can be

2679-404: The lowest to highest levels of food chains. PAHs transform slowly to a wide range of degradation products. Biological degradation by microbes is a dominant form of PAH transformation in the environment. Soil-consuming invertebrates such as earthworms speed PAH degradation, either through direct metabolism or by improving the conditions for microbial transformations. Abiotic degradation in

2736-402: The most important for the characterization of the properties of that PAH. For example, phenanthrene has two Clar structures: one with just one aromatic sextet (the middle ring), and the other with two (the first and third rings). The latter case is therefore the more characteristic electronic nature of the two. Therefore, in this molecule the outer rings have greater aromatic character whereas

2793-551: The overall distribution also suggested that the PAHs in London soils had undergone weathering and been modified by a variety of pre-and post-depositional processes such as volatilization and microbial biodegradation . Managed burning of moorland vegetation in the UK has been shown to generate PAHs which become incorporated into the peat surface. Burning of moorland vegetation such as heather initially generates high amounts of two- and three-ringed PAHs relative to four- to six-ringed PAHs in surface sediments, however, this pattern

2850-530: The size of the PAH. The dominant sources of PAHs in the environment are from human activity: wood-burning and combustion of other biofuels such as dung or crop residues contribute more than half of annual global PAH emissions, particularly due to biofuel use in India and China. As of 2004, industrial processes and the extraction and use of fossil fuels made up slightly more than one quarter of global PAH emissions, dominating outputs in industrial countries such as

2907-462: The sp structure of benzene. This class is largely a subset of the alternant PAHs, but is considered to include unstable or hypothetical compounds like triangulene or heptacene . As of 2012, over 300 benzenoid hydrocarbons had been isolated and characterized. The aromaticity varies for PAHs. According to Clar's rule , the resonance structure of a PAH that has the largest number of disjoint aromatic pi sextets —i.e. benzene -like moieties—is

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2964-569: The total PAH content (33 PAH) ranged from 6 to 88 mg/kg and fluoranthene and pyrene were generally the most abundant PAHs. Benzo[ a ]pyrene (B a P), the most toxic of the parent PAHs, is widely considered a key marker PAH for environmental assessments; the normal background concentration of B a P in the London urban sites was 6.9 mg/kg (dry soil weight). London soils contained more stable four- to six-ringed PAHs which were indicative of combustion and pyrolytic sources, such as coal and oil burning and traffic-sourced particulates. However,

3021-466: The total integrated infrared luminosity of galaxies. PAHs generally trace regions of cold molecular gas, which are optimum environments for the formation of stars. NASA's Spitzer Space Telescope and James Webb Space Telescope include instruments for obtaining both images and spectra of light emitted by PAHs associated with star formation . These images can trace the surface of star-forming clouds in our own galaxy or identify star forming galaxies in

3078-498: The tricyclic species phenanthrene and anthracene . Most authors exclude compounds that include heteroatoms in the rings, or carry substituents . A polyaromatic hydrocarbon may have rings of various sizes, including some that are not aromatic. Those that have only six-membered rings are said to be alternant . The following are examples of PAHs that vary in the number and arrangement of their rings: Most PAHs, like naphthalene, anthracene, and coronene, are planar. This geometry

3135-475: The two extreme hydrogen atoms. Adding two more rings on the same sense yields heptahelicene in which the two extreme rings overlap. These non-planar forms are chiral, and their enantiomers can be isolated. The benzenoid hydrocarbons have been defined as condensed polycyclic unsaturated fully-conjugated hydrocarbons whose molecules are essentially planar with all rings six-membered. Full conjugation means that all carbon atoms and carbon-carbon bonds must have

3192-715: Was being touted as a potential space port in the Upper Peninsula, in tandem with Wurtsmith. On January 18, 1994 Wurtsmith was listed as a Superfund due to extensive groundwater contamination with heavy metals, polycyclic aromatic hydrocarbons, volatile organic compounds , including trichloroethylene , 1,1-dichloroethane, 1,1,1-trichloroethane, and vinyl chloride . In March 2010 the Michigan Department of Environment, Great Lakes, and Energy (EGLE) became aware of Per- and polyfluoroalkyl substances concentrations in groundwater, when EGLE staff sampled at

3249-686: Was discovered, and as of 2022 remediation is still ongoing. During the Cold War , Wurtsmith was one of three Strategic Air Command (SAC) bases in Michigan with the B-52 bomber , the others ( Kincheloe AFB and Sawyer AFB ) were in the Upper Peninsula . The base was named in honor of Major General Paul Wurtsmith , commander of SAC's Eighth Air Force, who was killed when his B-25 Mitchell bomber crashed on Cold Mountain near Asheville, North Carolina, on September 13, 1946. In 2022, Granot Loma

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