ABSTRACT

Note: Impurities identified in refined ingots of commercially available ex-coal tar include 7methylanthracene, 1-phenylnaphthalene, and fluoranthene (Marciniak, 2002). CASRN: 129-00-0; molecular formula: C16H10; FW: 202.26; RTECS: UR2450000; Merck Index: 12, 8147 Physical state and color: Colorless solid (tetracene impurities impart a yellow color) or monoclinic prisms crystallized from alcohol. Solutions have a slight blue fluorescence. Melting point (°C): 156 (Weast, 1986) 149 (Sims et al., 1988) Boiling point (°C): 393 (Weast, 1986) Density (g/cm3): 1.271 at 23 °C (Weast, 1986) Diffusivity in water (x 10-5 cm2/sec): 0.490 at 40 °C (open tube elution method, Gustafson and Dickhut, 1994) Dissociation constant, pKa: >15 (Christensen et al., 1975) Flash point (°C): >210 (Acros Organics, 2002) Entropy of fusion (cal/mol⋅K): 8.6 (Wauchope and Getzen, 1972) Heat of fusion (kcal/mol): 3.66 (Wauchope and Getzen, 1972) Henry’s law constant (x 10-5 atm⋅m3/mol): 1.09 (Mackay and Shiu, 1981) 1.97 at 25 °C (de Maagd et al., 1998) 1.87 (batch stripping, Southworth, 1979) 1.19 at 25 °C (gas stripping-GC, Shiu and Mackay, 1997) 0.42, 0.68, 1.09, 1.69, and 2.42 at 4.1, 11.0, 18.0, 25.0, and 31.0 °C, respectively (Bamford et al.,

1998) 0.490 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999)

7.43 (Lias, 1998) Bioconcentration factor, log BCF: 3.43 (Daphnia pulex, Southworth et al., 1978) 3.43 (Daphnia magna, Newsted and Giesy, 1987) 2.66 (goldfish, Ogata et al., 1984) 0.72 (Polychaete sp.), 1.12 (Capitella capitata) (Bayona et al., 1991) 4.56 for the alga, Selenastrum capricornutum (Casserly et al., 1983) Apparent values of 4.2 (wet wt) and 6.0 (lipid wt) for freshwater isopods including Asellus

aquaticus (L.) (van Hattum et al., 1998) 3.03 (freshwater mussel Utterbackia imbecillis, Weinstein et al., 2001) Soil organic carbon/water partition coefficient, log Koc: 4.66 (aquifer material, Abdul et al., 1987) 4.92 (Schwarzenbach and Westall, 1981) 4.88 (Chin et al., 1988) 4.81 (Means et al., 1979) 4.74 (Webster soil, Woodburn et al., 1989) 4.80 (Hassett et al., 1980) 4.79 (Flint aquifer sample, Abdul and Gibson, 1986) 5.13 (estuarine sediment, Vowles and Mantoura, 1987) 4.67 (Socha and Carpenter, 1987) 5.23 (Gauthier et al., 1987) 5.18 (Karickhoff et al., 1979) 6.51 (average, Kayal and Connell, 1990) 4.88 (fine sand, Enfield et al., 1989) 4.77, 4.82 (RP-HPLC immobilized humic acids, Szabo et al., 1990) 4.94 (Mississippi sediment), 4.98 (Ohio River sediment) (Karickhoff and Morris, 1985) 4.83 (Karickhoff, 1981a) 4.64-4.83 (Illinois sediment), 4.70 (North Dakota sediment), 4.76 (West Virginia soil), 4.92

(Indiana sediment), 4.80 (Georgia sediment), 4.81 (Iowa loess), 4.88 (Kentucky sediment), 4.93 (South Dakota sediment) (Means et al., 1980)

4.97, 5.11, 6.02, 6.11, 6.53 (San Francisco, CA mudflat sediments, Maruya et al., 1996) 6.6 (average value using 8 river bed sediments from the Netherlands, van Hattum et al., 1998) Average Kd values for sorption of pyrene to corundum (α-Al2O3) and hematite (α-Fe2O3) were

0.231 and 0.983 mL/g, respectively (Mader et al., 1997) 3.92 and 4.03 for Na+-montmorillonite containing 0.025 and 0.017 foc, respectively (Onken and

Traina, 1997) 5.0 (HPLC-humic acid column, Jonassen et al., 2003) 5.61 (Calvert silt loam, Xia and Ball, 1999) 5.70 (cuticle), 4.69 (humic acid), 5.50 (humin), 5.15 (degraded lignin), 5.05 (lignite), 4.94 (peat)

(Chefetz et al., 2000) 4.17-7.40 based on 111 sediment determinations; average value = 5.11 (Hawthorne et al., 2006) Octanol/water partition coefficient, log Kow: 4.77 at 25 °C (dialysis-HPLC, Andersson and Schräder, 1999) 4.88 (Chou and Jurs, 1979) 5.09 (Means et al., 1979) 5.17 at 25 °C (modified shake-flask-UV spectrophotometry, Sanemasa et al., 1994) 5.22 (Bruggeman et al., 1982)

In benzene: 0.0734 at 32.4 °C, 0.1506 at 58.6 °C, 0.1896 at 66.8 °C, 0.2441 at 76.2 °C, 0.3014 at

84.6 °C (shake flask-gravimetric, McLaughlin and Zainal, 1959). At 26.0 °C: 2-methoxyethanol (0.01717), 2-ethoxyethanol (0.03046), 2-propoxyethanol (0.03400),

2-butoxyethanol (0.03790), 3-methoxy-1-butanol (0.02541) (McHale et al., 1997). Solubility in water: 91 µg/L at 20 °C (shake flask-UV spectrophotometry, Schlautman et al., 2004) 150 µg/L at 20 °C (laser multiphoton ionization, Gridin et al., 1998) 65.0 µg/L at 22 °C (shake flask-HPLC, Weinstein et al., 2001) 160 µg/L at 26 °C, 32 µg/L at 24 °C (practical grade, Verschueren, 1983) 13 mg/kg at 25 °C. In seawater (salinity = 35 g/kg): 56, 71, and 89 µg/kg at 15, 20, and 25 °C,

respectively (Rossi and Thomas, 1981) 13 µg/L at 25 °C (Miller et al., 1985) 135 µg/L at 25 °C (shake flask-fluorescence, Mackay and Shiu, 1977) 135 µg/L at 24 °C (Means et al., 1979) 132 µg/kg at 25 °C, 162 µg/kg at 29 °C (generator column-HPLC/UV spectrophotometry, May et

al., 1978a) 171 µg/L at 25 °C (fluorescence-UV spectrophotometry, Schwarz and Wasik, 1976) In mg/kg: 0.124, 0.128, 0.129 at 22.2 °C, 0.228, 0.235 at 34.5 °C, 0.395, 0.397, 0.405 at 44.7 °C,

0.556, 0.558, 0.576 at 50.1 °C, 0.75, 0.75, 0.77 at 55.6 °C, 0.74 at 56.0 °C, 0.90, 0.95, 0.96 at 60.7 °C, 1.27, 1.29 at 65.2 °C, 1.83, 1.86, 1.89 at 71.9 °C, 2.21 at 74.7 °C (shake flask-UV spectrophotometry, Wauchope and Getzen, 1972)

160, 165 µg/L at 27 °C (shake flask-nephelometry, Davis et al., 1942) In nmol/L: 270 at 12.2 °C, 339 at 15.5 °C, 391 at 17.4 °C, 457 at 20.3 °C, 578 at 23.0 °C, 582 at

23.3 °C, 640 at 25.0 °C, 713 at 26.2 °C, 7.18 at 26.7 °C, 809 at 28.5 °C, 930 at 31.3 °C (shake flask-UV spectrophotometry, Schwarz, 1977)

175 µg/L at 25 °C (shake flask-UV spectrophotometry, Klevens, 1950) 133 µg/L at 25 °C (HPLC-fluorescence, Walters and Luthy, 1984) 150 µg/L in Lake Michigan water at ≈ 25 °C (Eadie et al., 1990; Fatiadi, 1967) 1 µmol/L at 25 °C (Edwards et al., 1991) At 20 °C: 470, 322, 318, and 311 nmol/L in doubly distilled water, Pacific seawater, artificial

seawater, and 35% NaCl, respectively (modified shake flask method-fluorometry, Hashimoto et al., 1984)

107 µg/L at 25 °C (generator column-HPLC, Vadas et al., 1991) 118 µg/L at 25 °C (Billington et al., 1988) In mole fraction (x 10-8): 4.832 at 4.70 °C, 5.211 at 9.50 °C, 6.413 at 14.30 °C, 8.310 at 18.70 °C,

9.709 at 21.20 °C, 12.11 at 25.50 °C, 15.14 at 29.90 °C (generator column-HPLC, May et al., 1983)

In mole fraction (x 10-8): 0.4221 at 8.54 °C, 0.56523 at 13.50 °C, 0.61778 at 14.46 °C, 0.50422 at 10.39 °C, 0.71638 at 16.70 °C, 0.7757 at 18.05 °C, 0.96782 at 21.53 °C, 1.5017 at 29.66 °C, 1.1851 at 25.55 °C, 1.3406 at 27.36 °C, 1.7200 at 32.28 °C (generator column-HPLC, Reza et al., 2000)

0.669 µmol/kg 25 °C (vapor saturation-UV spectrofluorometry, Wu et al., 1990) Vapor pressure (x 10-7 mmHg): 6.85 at 25 °C (extrapolated from vapor pressures determined at higher temperatures, Pupp et al.,

1974) 379 at 68.90 °C, 1,080 at 71.75 °C, 1,410 at 74.15 °C, 1,670 at 75.85 °C, 2,060 at 78.20 °C, 2,160

at 78.90 °C, 2,920 at 81.70 °C, 3,070 at 82.65 °C, 3,040 at 82.70 °C, 3,790 at 85.00 °C, 3,800 at 85.25 °C (effusion method, Bradley and Cleasby, 1953)

column-HPLC, Wasik et al., 1983)

367 at 25 °C (estimated-GC, Bidleman, 1984) 564, 848 at 25 °C (subcooled liquid vapor pressure calculated from GC retention time data,

Hinckley et al., 1990) 647, 1,823, and 1,568 at 46.95, 56.99, and 57.98 °C, respectively (Oja and Suuberg, 1998) 180 at 25 °C (extrapolated from vapor pressures determined at higher temperatures, Tesconi and

Yalkowsky, 1998) Environmental fate: Biological. When pyrene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, complete degradation was demonstrated at the 5 mg/L substrate concentration after 2 wk. At a substrate concentration of 10 mg/L, however, only 11 and 2% losses were observed after 7 and 14 d, respectively (Tabak et al., 1981). Contaminated soil from a manufactured coal gas plant that had been exposed to crude oil was spiked with pyrene (400 mg/kg soil) to which Fenton’s reagent (5 mL 2.8 M hydrogen peroxide; 5 mL 0.1 M ferrous sulfate) was added. The treated and nontreated soil samples were incubated at 20 °C for 56 d. Fenton’s reagent greatly enhanced the mineralization of pyrene by indigenous microorganisms. The amounts of pyrene recovered as carbon dioxide after treatment with and without Fenton’s reagent were 16 and 5%, respectively. Pretreatment of the soil with a surfactant (10 mM sodium dodecylsulfate) before addition of Fenton’s reagent increased the mineralization rate 55% as compared to nontreated soil (Martens and Frankenberger, 1995). Sack et al. (1997) reported that pyrene was degraded by an Aspergillus niger strain isolated from a mineral oil-contaminated soil in La Plata, Argentina. The major metabolite was identified via GC/MS as 1-methoxypyrene. 1-Pyrenol was identified as a minor metabolite. Soil. The reported half-lives for pyrene in a Kidman sandy loam and McLaurin sandy loam are 260 and 199 d, respectively (Park et al., 1990). Plant. Hückelhoven et al. (1997) studied the metabolism of pyrene by suspended plant cell cultures of soybean, wheat, jimsonweed, and purple foxglove. Soluble metabolites were only detected in foxglove and wheat. Approximately 90% of pyrene was transformed in wheat. In foxglove, 1-hydroxypyrene methyl ether was identified as the main metabolite but in wheat, the metabolites were identified as conjugates of 1-hydroxypyrene. Photolytic. Adsorption onto garden soil for 10 d at 32 °C and irradiated with UV light produced 1,1′- bipyrene, 1,6-pyrenedione, 1,8-pyrenedione, and three unidentified compounds (Fatiadi, 1967). Microbial degradation by Mycobacterium sp. yielded the following ring-fission products: 4-phenanthroic acid, 4-hydroxyperinaphthenone, cinnamic acid, and phthalic acid. The compounds pyrenol and the cis-and trans-4,5-dihydrodiols of pyrene were identified as ring-oxidation products (Heitkamp et al., 1988). Silica gel coated with pyrene and suspended in an aqueous solution containing nitrite ion and subjected to UV radiation yielded the tentatively identified product 1-nitropyrene (Suzuki et al., 1987). 1-Nitropyrene coated on glass surfaces and exposed to natural sunlight resulted in the formation of hydroxypyrene, possibly pyrenedione, dihydroxypyrene, and other unidentified compounds (Benson et al., 1985). Matsuzawa et al. (2001) investigated the photochemical degradation of five polycyclic aromatic hydrocarbons in diesel particulate matter deposited on the ground and in various soil components. The photochemical degradation by artificial sunlight was accomplished using a 900-W xenon lamp. Light from this lamp was passed through a glass filter to eliminate light of shorter wavelengths (λ <290 nm). The intensity of this light was about 170 mW/cm2. In addition, a solar simulator equipped with a 300-W xenon lamp was used to provide the maximum sunlight intensity observed in Toyko (latitude 35.5 °N). The half-lives of pyrene in diesel particulate matter using 900-and 300-W sources were 9.24 and 737.55 h, respectively. The following half-lives were determined for pyrene adsorbed on various soil components using 900-

montmorillonite, 0.80 h for silica gel, and 0.98 h for alumina. 1-Nitropyrene also formed when pyrene deposited on glass filter paper containing sodium nitrite was irradiated with UV light at room temperature (Ohe, 1984). This compound was reported to have formed from the reaction of pyrene with NOx in urban air from St. Louis, MO (Randahl et al., 1982). Behymer and Hites (1985) determined the effect of different substrates on the rate of photooxidation of pyrene using a rotary photoreactor. The photolytic half-lives of pyrene using silica gel, alumina, and fly ash were 21, 31, and 46 h, respectively. In a 5-m deep surface water body, the calculated half-lives for direct photochemical transformation at 40 °N latitude in the midsummer during midday were 5.9 and 4.2 d with and without sediment-water partitioning, respectively (Zepp and Schlotzhauer, 1979). Schwarz and Wasik (1976) reported a fluorescence quantum yield of 0.69 for pyrene in water. Chemical/Physical. At room temperature, concentrated sulfuric acid will react with pyrene to form a mixture of disulfonic acids. In addition, an atmosphere containing 10% sulfur dioxide transformed pyrene into many sulfur compounds, including pyrene-1-sulfonic acid and pyrenedisulfonic acid (Nielsen et al., 1983). 2-Nitropyrene was the sole product formed from the gas-phase reaction of pyrene with OH radicals in a NOx atmosphere (Arey et al., 1986). Pyrene adsorbed on glass fiber filters reacted rapidly with N2O5 to form 1-nitropyrene. When pyrene was exposed to nitrogen dioxide, no reaction occurred. However, in the presence of nitric acid, nitrated compounds were produced (Yokley et al., 1985). Ozonation of water containing pyrene (10-200 µg/L) yielded short-chain aliphatic compounds as the major products (Corless et al., 1990). A monochlorinated pyrene was the major product formed during the chlorination of pyrene in aqueous solutions. At pH 4, the reported half-lives at chlorine concentrations of 0.6 and 10 mg/L were 8.8 and <0.2 h, respectively (Mori et al., 1991). A volatilization rate constant of 1.1 x 10-4/sec was determined when pyrene on a glass surface was subjected to an air flow rate of 3 L/min at 24 °C (Cope and Kalkwarf, 1987). Pyrene will not hydrolyze in water (Kollig, 1993). Exposure limits: Potential occupational carcinogen. No individual standards have been set; however, as a constituent in coal tar pitch volatiles, the following exposure limits have been established (mg/m3): NIOSH REL: TWA 0.1 (cyclohexane-extractable fraction), IDLH 80; OSHA PEL: TWA 0.2 (benzene-soluble fraction); ACGIH TLV: TWA 0.2 (benzene solubles). Toxicity: EC10 (21-d) for Folsomia fimetaria 10 mg/kg (Sverdrup et al., 2002). EC50 (21-d) for Folsomia fimetaria 16 mg/kg (Sverdrup et al., 2002). LC50 (21-d) for Folsomia fimetaria 53 mg/kg (Sverdrup et al., 2002). LC50 (10-d) for Rhepoxynius abronius 2.81 mg/g organic carbon (Swartz et al., 1997). LC50 (24-h) for Utterbackia imbecillis >28.2 µg/L (Weinsten and Polk, 2001). LC50 (16-h) for Utterbackia imbecillis >28.2 µg/L (Weinsten and Polk, 2001). LC50 (8-h) for Utterbackia imbecillis >28.2 µg/L (Weinsten and Polk, 2001). LC50 (inhalation) for rats 170 mg/m3 (quoted, RTECS, 1985). LD50 (24-h) for Utterbackia imbecillis >47.1 µg/g (Weinsten and Polk, 2001). LD50 (16-h) for Utterbackia imbecillis >47.1 µg/g (Weinsten and Polk, 2001). LD50 (8-h) for Utterbackia imbecillis >47.1 µg/g (Weinsten and Polk, 2001). LD50 (4-d intraperitoneal) and LD50 (7-d intraperitoneal) values for mice were 514 and 678 mg/kg, respectively (Salamone, 1981). Acute oral LD50 for mice 800 mg/kg, rats 2,700 mg/kg (quoted, RTECS, 1985). Source: Detected in groundwater beneath a former coal gasification plant in Seattle, WA at a

from 0.16 to 24 mg/L with a mean value of 5.54 mg/L (Westerholm and Li, 1994). Identified in Kuwait and South Louisiana crude oils at concentrations of 4.5 and 3.5 ppm, respectively (Pancirov and Brown, 1975). Based on laboratory analysis of 7 coal tar samples, pyrene concentrations ranged from 900 to 18,000 ppm (EPRI, 1990). Detected in 1-yr aged coal tar film and bulk coal tar at concentrations of 2,700 and 2,900 mg/kg, respectively (Nelson et al., 1996). Lehmann et al. (1984) reported a pyrene concentration of 125 mg/g in a commercial anthracene oil. Identified in high-temperature coal tar pitches used in electrodes at concentrations ranging from 4,500 to 34,900 mg/kg (Arrendale and Rogers, 1981). Lee et al. (1992a) equilibrated eight coal tars with distilled water at 25 °C. The maximum concentration pyrene observed in the aqueous phase is 0.1 mg/L. Nine commercially available creosote samples contained pyrene at concentrations ranging from 31,000 to 100,000 mg/kg (Kohler et al., 2000). Also detected in asphalt fumes at an average concentration of 140.21 ng/m3 (Wang et al., 2001). Schauer et al. (1999) reported pyrene in diesel fuel at a concentration of 64 µg/g and in a dieselpowered medium-duty truck exhaust at an emission rate of 71.9 µg/km. California Phase II reformulated gasoline contained pyrene at a concentration of 3.38 g/kg. Gasphase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were approximately 4.28 and 160 µg/km, respectively (Schauer et al., 2002). Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The respective gas-phase and particle-phase emission rates of pyrene were 1.87 and 3.78 mg/kg of pine burned, 2.40 and 1.23 mg/kg of oak burned, and 2.70 and 0.585 mg/kg of eucalyptus burned. Under atmospheric conditions, a low rank coal (0.5-1 mm particle size) from Spain was burned in a fluidized bed reactor at seven different temperatures (50 °C increments) beginning at 650 °C. The combustion experiment was also conducted at different amounts of excess oxygen (5 to 40%) and different flow rates (700 to 1,100 L/h). At 20% excess oxygen and a flow rate of 860 L/h, the amount of pyrene emitted ranged from 29.9 ng/kg at 700 °C to 402.9 ng/kg at 750 °C. The greatest amount of PAHs emitted were observed at 750 °C (Mastral et al., 1999). Drinking water standard: No MCLGs or MCLs have been proposed by the U.S. EPA (2000). Use: Research chemical. Derived from industrial and experimental coal gasification operations where the maximum concentrations detected in gas and coal tar streams were 9.2 and 24 mg/m3, respectively (Cleland, 1981).