6PPD Research at Columbia Environmental Research Center
CERC scientists are evaluating the exposure and effects of 6PPD.
6PPD is a chemical additive that protects tires from damage due to certain reactive oxygen species. 6PPD, when in contact with ozone, reacts to form the derivative 6PPD-quinone (6PPD-Q). As tires wear with time, this derivative is dispensed into the environment, travels through drainage systems when it rains and, eventually, finds its way into surface waters. The presence of 6PPD-Q in these bodies of water is highly toxic to certain species of fish, including Coho Salmon, Rainbow Trout, Brook Trout and White-spotted Char. Our research suggests that 6PPD-Q is not toxic to freshwater invertebrates.
Mussels and Mayflies
Researchers at Columbia Environmental Research Center (CERC) are exploring various facets of 6PPD toxicity. Namely, acute studies were conducted evaluating the sensitivity of freshwater mussels (Lampsilis siliquoidea) and mayflies (Neocloeon triangulifer) exposed to 6PPD, 6PPD-Q and an ozonated solution of 6PPD containing a combination of 6PPD and 6PPD-Q (hereafter referred to as 6PPD-O). Interestingly, the compound known for its toxicity to Coho Salmon, 6PPD-Q, did not cause mortality or increased sensitivity in studies with mussels and mayflies at concentrations up to the solubility limit. However, parent forms 6PPD and 6PPD-O did have effects. These experiments also revealed a color change in the test solutions over time that was independent of light. This change could indicate the formation of transformation products due to a hydrolysis reaction, the effects of which are currently unknown.
6PPD Research Happening at CERC with Mayflies and Mussels
Coho Salmon and Rainbow Trout
An upcoming study will evaluate the effects of 6PPD-Q on Coho Salmon and salmonid relative, Rainbow Trout, in a 96-hour exposure period. These findings will be significant in determining accurate Species Sensitivity Distributions for developing ambient water quality criteria. Many other studies that aimed to evaluate sensitivity do not meet the USEPA’s guidelines for data quality due to insufficient test duration (less than 96 hours), insufficient analytical chemistry and the excessive fish loading rates resulting in unstable toxicant concentrations. CERC’s specialized laboratories make it possible to overcome these barriers. The toxicology facility is home to 23 diluter systems that can create the pulsed flow-through conditions needed to overcome excessive loading of fish in test chambers. Diluter systems will run on a 1-hour cycle, establishing stable toxicant concentrations. The test solutions will be analyzed at the USGS Kansas Water Science Center’s Organic Geochemistry Research Laboratory using UPLC/MS/MS, ensuring sufficient analytical chemistry requirements are met.
Partnering
The USGS-CERC partners with academic, state, federal, tribal, and private sector partners to conduct basic and applied research. Opportunities exist to collaborate with USGS within the scope of the USGS Strategic Science Vision.
CERC scientists are evaluating the exposure and effects of 6PPD.
6PPD is a chemical additive that protects tires from damage due to certain reactive oxygen species. 6PPD, when in contact with ozone, reacts to form the derivative 6PPD-quinone (6PPD-Q). As tires wear with time, this derivative is dispensed into the environment, travels through drainage systems when it rains and, eventually, finds its way into surface waters. The presence of 6PPD-Q in these bodies of water is highly toxic to certain species of fish, including Coho Salmon, Rainbow Trout, Brook Trout and White-spotted Char. Our research suggests that 6PPD-Q is not toxic to freshwater invertebrates.
Mussels and Mayflies
Researchers at Columbia Environmental Research Center (CERC) are exploring various facets of 6PPD toxicity. Namely, acute studies were conducted evaluating the sensitivity of freshwater mussels (Lampsilis siliquoidea) and mayflies (Neocloeon triangulifer) exposed to 6PPD, 6PPD-Q and an ozonated solution of 6PPD containing a combination of 6PPD and 6PPD-Q (hereafter referred to as 6PPD-O). Interestingly, the compound known for its toxicity to Coho Salmon, 6PPD-Q, did not cause mortality or increased sensitivity in studies with mussels and mayflies at concentrations up to the solubility limit. However, parent forms 6PPD and 6PPD-O did have effects. These experiments also revealed a color change in the test solutions over time that was independent of light. This change could indicate the formation of transformation products due to a hydrolysis reaction, the effects of which are currently unknown.
6PPD Research Happening at CERC with Mayflies and Mussels
Coho Salmon and Rainbow Trout
An upcoming study will evaluate the effects of 6PPD-Q on Coho Salmon and salmonid relative, Rainbow Trout, in a 96-hour exposure period. These findings will be significant in determining accurate Species Sensitivity Distributions for developing ambient water quality criteria. Many other studies that aimed to evaluate sensitivity do not meet the USEPA’s guidelines for data quality due to insufficient test duration (less than 96 hours), insufficient analytical chemistry and the excessive fish loading rates resulting in unstable toxicant concentrations. CERC’s specialized laboratories make it possible to overcome these barriers. The toxicology facility is home to 23 diluter systems that can create the pulsed flow-through conditions needed to overcome excessive loading of fish in test chambers. Diluter systems will run on a 1-hour cycle, establishing stable toxicant concentrations. The test solutions will be analyzed at the USGS Kansas Water Science Center’s Organic Geochemistry Research Laboratory using UPLC/MS/MS, ensuring sufficient analytical chemistry requirements are met.
Partnering
The USGS-CERC partners with academic, state, federal, tribal, and private sector partners to conduct basic and applied research. Opportunities exist to collaborate with USGS within the scope of the USGS Strategic Science Vision.