Benzo[ghi]fluoranthen

EC50; Species: Chlorella fusca var. vacuolata (Green Algae) Strain 21115, 75000 cells/mL; Conditions: freshwater, static, 28 °C, pH 6.9; Concentration: 0.045 umol/L for 24 hr (95% confidence interval: 0.0429-0.0474 umol/L); Effect: population, increased population growth rate /98% purity/

EC50; Species: Chlorella fusca var. vacuolata (Green Algae) Strain 211; Conditions: freshwater, static; Concentration: 0.0437 umol/L for 24 hr; Effect: population, decreased abundance /formulated product/

EC50; Species: Chlorella fusca var. vacuolata (Green Algae) Strain 211; Conditions: freshwater, static; Concentration: 0.0102 umol/L for 24 hr; Effect: population, decreased index to population size, count number, abundance /formulated product/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.8X10+5(SRC), determined from a structure estimation method(2), indicates that benzo(ghi)fluoranthene is expected to be immobile in soil(SRC). Volatilization of benzo(ghi)fluoranthene from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.3X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). In addition, adsorption to soil is expected to attenuate potential volatilization(SRC). Benzo(ghi)fluoranthene is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.9X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Polycyclic aromatic hydrocarbons (PAHs), such as benzo(ghi)fluoranthene, with more than 3 rings appear to be extremely stable to biodegradation(3). Breakdown in soil generally takes weeks to months for PAHs with 3 rings, primarily by action of microorganisms; PAHs with 4 or more rings are generally resistant to biodegradation(4,5). Soil microbes adapted specifically to PAHs are capable of biodegrading benzo(ghi)fluoranthene(6). Benzo(ghi)fluoranthene absorbs light strongly at wavelengths >290 nm(7) and, therefore, is expected to be susceptible to direct photolysis on soil surfaces exposed to sunlight(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.8X10+5(SRC), determined from a structure estimation method(2), indicates that benzo(ghi)fluoranthene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.3X10-6 atm-cu m/moleSRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 41 and 305 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is >10 years if adsorption is considered(4). According to a classification scheme(5), an estimated BCF of 2040(SRC), from an estimated log Kow of 5.52(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is very high, provided the compound is not metabolized by the organism(SRC). However, benzo(ghi)fluoranthene may not bioconcentrate in aquatic organisms which contain microsomal oxidase, such as fish, as this enzyme enables the rapid metabolism of certain polycyclic aromatic hydrocarbons(6). Polycyclic aromatic hydrocarbons (PAHs) with four or more rings, such as benzo(ghi)fluoranthene, are generally expected to be resistant to biodegradation(7). Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions(3). Benzo(ghi)fluoranthene absorbs strongly at wavelengths >290 nm(8), and therefore is expected to be susceptible to direct photolysis at water surfaces exposed to sunlight(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), benzo(ghi)fluoranthene, which has an estimated vapor pressure of 1.9X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase benzo(ghi)fluoranthene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 6.2 hours(SRC), calculated from its rate constant of 6.2X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). Particulate-phase benzo(ghi)fluoranthene may be removed from the air by wet and dry deposition(SRC). Benzo(ghi)fluoranthene absorbs strongly at wavelengths >290 nm(3) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC).

Margarines, butter and vegetable oils collected from Finnish markets and the margarine industry were analyzed for PAHs(1); benzo(ghi)fluoranthene was detected in 18 of 22 samples at concentrations ranging from 0.05 to 2.4 ug/kg(1). Smoke from the charcoal grilling of meat patties contained benzo(ghi)fluoranthene levels of 0.96 ug/kg meat(2). Emissions of benzo(ghi)fluoranthene from Chinese cooking, as sampled from four restaurants in Guangzhou City, China, ranged from 13-160 ng/mg(3).

IDENTIFICATION AND USE: Benzo(ghi)fluoranthene is a polycyclic aromatic hydrocarbon (PAH). There is no commercial production or known use of this compound. HUMAN STUDIES: Human exposure to benzo(ghi)fluoranthene occurs primarily through the smoking of tobacco, inhalation of polluted air and by ingestion of food and water contaminated by combustion effluents. ANIMAL STUDIES: Benzo(ghi)fluoranthene was tested for carcinogenicity in one study in female mice by skin painting; no skin tumor was observed. Benzo(ghi)fluoranthene was mutagenic to Salmonella typhimurium in the presence of an exogenous metabolic system.

Benzo(ghi)fluoranthene was identified in gasoline engine exhaust at concentrations of 112-244 ug/L fuel(1). Gaseous emissions from gasoline-powered chain saws had combined benzofluoranthene isomer concentrations ranging from 1.2-2.0 ug/cu m(2). Two turbine engine exhaust had combined benzofluoranthene isomer levels of 33.17 and 67.17 ng/cu m(3). Lawn mower engines were found to emit benzo(ghi)fluoranthene levels of 7.9-13.5 ug/hr with catalyst controls and 20.3-51.9 ug/hr without catalyst controls(4). Monitoring conducted in Los Angeles, CA in 1993 near traffic tunnels identified benzo(ghi)fluoranthene emission rates of 70.9 and 19.7 ug/L fuel in the vapor-phase and particulate phase respectively(5). Benzo(ghi)fluoranthene was detected in particle emissions from industrial boiler burning of No. 2 distillate fuel(6). Coke oven emission were found to contain benzo(ghi)fluoranthene(7). The mean emission factor of benzo(ghi)fluoranthene detected from light and heavy duty vehicles in a California roadway tunnel ranged from 0.44-89.99 ug/kg fuel burned(8). Benzo(ghi)fluoranthene emissions from catalyst-equipped gasoline-powered vehicles was 0.276 and 0.063 ug/km in the gas and particle phases respectively(9); emissions from non-catalyst-equipped gasoline-powered vehicles was 10.7 and 46.8 ug/km in the gas and particle phases respectively(9).

Benzo(ghi)fluoranthene was identified in wastewater effluents from an aluminum factory in Sweden(1). Aerosol emission rate of benzo(ghi)fluoranthene from hot asphalt roofing tar pot fumes was 4.3 ug/g(2).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of benzo(ghi)fluoranthene can be estimated to be 1.8X10+5(SRC). According to a classification scheme(2), this estimated Koc value suggests that benzo(ghi)fluoranthene is expected to be immobile in soil. Based on monitoring of water and sediment layers conducted in the Baltic Sea, benzo(ghi)fluoranthene had an apparent log Koc of 5.0-6.7(3).

URBAN/SUBURBAN: Air samples collected in Antwerp, Belgium in 1974-1975 contained combined benzofluoranthene isomer concentrations of 15.68 ng/cu m in the summer and 114.46 ng/cu m in the winter(1). Aerosol collected from six sites in Hong Kong and China in 1993 contained benzo(ghi)fluoranthene concentrations of 24-1621 pg/cu m(2). Aerosols collected from Kenmore Sqaure in Boston, MA during June-July 1994 had a benzo(ghi)fluoranthene concentration of 0.90 ng/cu cm(3). Air particulate sampling conducted in Sacramento, Modesto and Bakersfield, CA during Dec 2000-Jan 2001 detected benzo(ghi)fluoranthene concentration ranges of 0-1380, 4-1130 and 0.72-618 pg/cu m respectively(4).

INDOOR AIR: Air monitoring conducted in the basement room of a home in Boulder, CO burning natural gas in a fireplace between 1997 and 2000 detected benzo(ghi)fluoranthene (concentration not reported)(1). In a 2003 study conducted in Sweden, the indoor air of 13 homes using wood-burning appliances contained a median benzo(ghi)fluoranthene concentration of 0.19 ng/cu m (mean 0.39 ng/cu m) while 10 homes without wood-burning appliances contained a median benzo(ghi)fluoranthene concentration below the limit of quantification (0.05-0.15 ng/cu m)(2).

RURAL/REMOTE: Air samples collected in Botrange, Belgium in 1974-1975 contained combined benzofluoranthene isomer concentrations of 2.06 ng/cu m in the summer and 6.53 ng/cu m in the winter(1). Samples of sea air collected near Ostend, Belgium in 1974-1975 contained benzofluoranthene concentrations of 65.51 ng/cu m in the winter(1). PM2.5 aerosol collected from sites in the southeastern US in 1999 and 2000 had benzo(ghi)fluoranthene concentrations of 0.01-0.04 ng/cu m(2). Aerosols collected from Quabbin Summit, MA during July 1994 had a benzo(ghi)fluoranthene concentration of 0.078 ng/cu cm(3). Benzo(ghi)fluoranthene was identified in air samples collected from high mountain regions of Europe during 1996-1998 monitoring in the Alps, the Pyrenees and Norway(4).

/GENOTOXICITY/ A number of isomeric C18H10 polycyclic aromatic hydrocarbons (PAHs), thought to be primarily cyclopenta-fused PAHs, are produced during the combustion and pyrolysis of fossil fuels. To determine the importance of their contributions to the total mutagenic activity of combustion and pyrolysis samples in which they are found, we characterized reference quantities of four C18H10 CP-PAHs: benzo[ghi]fluoranthene (BF), cyclopenta[cd]pyrene (CPP), cyclopent[hi]acephenanthrylene (CPAP), and cyclopent[hi]aceanthrylene (CPAA). Synthesis of CPAA and CPAP is described. The availability of reference samples of these isomers also proved to be an essential aid in the identification of the C18H10 species often found in combustion and pyrolysis samples. Chemical analysis of selected combustion and pyrolysis samples showed that CPP was generally the most abundant C18H10 isomer, followed by CPAP and BF. CPAA was detected only in pyrolysis products from pure PAHs. We tested the four C18H10 PAHs for mutagenicity in a forward mutation assay using S. typhimurium. CPP, BF, and CPAA were roughly twice as mutagenic as benzo[a]pyrene (BaP), whereas CPAP was only slightly active. These PAHs were also tested for mutagenic activity in human cells. In this assay, CPP and CPAA were strongly mutagenic but less active than BaP, whereas CPAP and BF were inactive at the dose levels tested. Also, the bacterial and human cell mutagenicity of CPAA and CPAP were compared with the mutagenicity of their monocyclopenta-fused analogs, aceanthrylene and acephenanthyrlene. Although the mutagenicities of CPAP and acephenanthrylene are similar, the mutagenic activity of CPAA is an order of magnitude greater than that of aceanthyrlene.

/OTHER TOXICITY INFORMATION/ Benzo(ghi)fluoranthene is present as a component of the total content of polynuclear aromatic compounds in the environment. Human exposure to benzo(ghi)fluoranthene occurs primarily through the smoking of tobacco, inhalation of polluted air and by ingestion of food and water contaminated by combustion effluents.