Water samples have been taken from Alaska to Florida by the USGS and results are in. Contaminated lakes and rivers show a higher concentration of polycyclic aromatic hydrocarbons (PAHs), on the rise since the 1960s. These contaminants are toxic for fish and other aquatic life.
Researchers have found the main source of the PAHs to be coal-tar-based pavement sealant. One of the most common uses for this material is the squiggly, shiny black lines that seal the cracks in roadways. While effective, this material has a life span of only three to five years and is easily being transmitted into lakes and stream ecosystems. Storm runoff is a common mode of travel for PAHs from the sealant into the lakes.
The USGS news release gives further details, and the full journal article is available in Science of the Total Environment. For further reading suggestions, see our recommended reading list on Understanding and Protecting Groundwater.
Photo from concierge.com.