CC_Minutes_2011_0523 - Laserfiche WebLink

Home

Our Environment and Us What are the Concerns? rg . Some PAHs are toxic to mammals(including humans),birds, fish,amphibians (such as frogs and salamanders), and plants.The aquatic inverte- brates—insects and other small creatures that live in :t streams and lakes—are particularly susceptible to PAH contamination,especially those that live in the mud where PAHs tend to accumulate. These inver- mi tebrates are an important part of the food chain and . are often monitored as indicators of stream quality °: (analogous to the "canary in the coal mine" con- cept). Possible adverse effects of PAHs on aquatic invertebrates include inhibited reproduction, delayed Tumors in brown bullhead catfish from the Anacostia River, emergence, sediment avoidance, and mortality. Pos- Washington,D.C.,are believed to be related to elevated PAH sible adverse effects on fish include fin erosion,liver concentrations(Pinkney and others,2009).Photograph by A.E. abnormalities, cataracts, and immune system impair- Pinkney. ments. The Probable Effect Concentration (PEC) of 22.8 mg/kg of total PAHs (MacDonald and others, 2000)—a widely used sediment quality guideline Human health risk from environmental con- that is the concentration in bed sediment expected to taminants usually is evaluated in terms of exposure have harmful effects on bottom-dwelling biota—is pathways. For example, people could potentially exceeded in one-third of the central and eastern U.S. be exposed to PAHs in sealcoat through ingestion urban lakes where PAH sources were studied. of abraded particles from driveways,parking lots, When turned over,red or play grounds, or through skin contact with the spotted newts that had abraded particles,either directly or by touching toys been exposed to sediment or other objects that have been in contact with the contaminated with pavement. Inhalation of wind-blown particles and_ coal-tar-based sealcoat of fumes that volatilize from sealed parking lots are had difficulty righting themselves(Bommarito other possible pathways. PAHs in streams and lakes and others,2010b). Poor rarely pose a human health risk from contact recre- reflexes could result ation or drinking water because of their tendency to in decreased survival. attach to sediment rather than to dissolve in water. Photograph by Megan Gibbons,Birmingham- Southern College. Scientific studies have shown a relation between coal-tar-based pavement sealcoat and harmful effects on aquatic life. • Aquatic communities downstream from storm- r water runoff from sealcoated parking lots were impaired(Scoggins and others, 2007). • Salamanders and newts exposed to sediment contaminated with coal-tar-based sealcoat had stunted growth, difficulty swimming or righting themselves, and liver problems (Bommarito and others, 2010a,b). Skin contact is one way humans can be exposed to PAHs. • Frogs exposed to sediment contaminated Parking lots and driveways with coal-tar-based sealcoat have with coal-tar-based sealcoat died, had stunted concentrations of PAHs hundreds to thousands of times higher growth, or developed more slowly than usual than those with asphalt-based sealcoat or no sealcoat.Photograph (Bryer and others, 2006). obtained from Corbis Images,Inc.