Just published today is a joint study between the Université de Lyon and the US Geological Survey (USGS) clearly demonstrates not only DNA damage, but also the fishes' ability to repair that damage. The research was published in the journal Science of the Total Environment.
One term used in the paper is "genotoxic." A substance is a genotoxin when it damages DNA. If unrepaired, that genotoxin would be considered a mutagen, causing permanent DNA damage.
Additional findings were:
- Co-exposure to runoff from coal-tar-sealcoated pavement and UVA (ultra-violet light) caused DNA damage.
- Significant genotoxicity occurred with a 1:100 dilution of runoff.
- Runoff collected up to 36 days following coal-tar-sealcoat application was genotoxic.
- Exposure to runoff from sealed pavement impaired an important DNA repair pathway.
- Repair capacity was impaired with a 1:10 dilution of runoff (1:100 not tested).
Research like this gives us another perspective on this common toxic product. This hurts children, adults, salamanders, fish, frogs, and benthic organisms.
If this product were necessary for national security or some greater altruistic effort, then maybe we should use it. But when the damage FAR outweighs the benefits, it is time to end the practice altogether.