Connect with us

Hi, what are you looking for?

CleanTechnica
While this shouldn't be surprising to anyone who has smelled the stuff when it's being applied, coal-tar-based sealants used on pavement are the primary source of toxic polycyclic aromatic hydrocarbons (PAHs) in streambed sediments in Milwaukee, Wisconsin, according to a new study from the US Geological Survey and the Milwaukee Metropolitan Sewerage District.

Research

USGS: Coal-Tar Sealant Is Primary Source Of PAH Contamination In Milwaukee Streams (Implications For Other Regions)

While this shouldn’t be surprising to anyone who has smelled the stuff when it’s being applied, coal-tar-based sealants used on pavement are the primary source of toxic polycyclic aromatic hydrocarbons (PAHs) in streambed sediments in Milwaukee, Wisconsin, according to a new study from the US Geological Survey and the Milwaukee Metropolitan Sewerage District.

While this shouldn’t be surprising to anyone who has smelled the stuff when it’s being applied, coal-tar-based sealants used on pavement are the primary source of toxic polycyclic aromatic hydrocarbons (PAHs) in streambed sediments in Milwaukee, Wisconsin, according to a new study from the US Geological Survey and the Milwaukee Metropolitan Sewerage District.

The findings, of course, very likely apply to many other regions as well, pretty much anywhere that coal-tar-based sealants are used extensively on pavement.

For those unfamiliar with the terminology being used, just think of that really dark black (at least initially) covering that you see on some parking lots, playgrounds, and driveways — that’s pavement treated with coal-tar-based sealants.

As the name implies, the sealant is made from “coal tar,” which is itself a human carcinogen (despite its regular use on playground pavement). It also contains high levels of PAHs, some of which are highly toxic to aquatic life and also to humans.

Here’s more from the press release:

“Scientists with the USGS collected sediment samples from 40 streambed sites and dust samples from six parking lot sites in the Milwaukee area to determine the likely sources and toxicity of PAHs in streams. They found that dust from coal-tar-sealant contributed about 42% to 94% of the PAHs to the samples, with the remainder of PAHs coming from sources such as coal combustion and vehicle emissions.

“78% of the sediment samples collected had PAH levels that could adversely affect aquatic organisms like aquatic insects. Among the most toxic samples collected were those from sections of Lincoln Creek, Underwood Creek and the West Milwaukee Ditch.”

Commenting on the findings, lead author and USGS scientist Austin Baldwin stated: “This study shows that PAHs pose a very real threat to aquatic organisms at the base of the food chain. In terms of toxicity to these organisms, PAHs are probably the most important contaminants in Milwaukee-area streams.”

What Baldwin means when he says “toxicity” is liver failure, fin erosion, immune system impairment, and cataract formation. Not minor health problems — rather major ones.

Baldwin continued: “Our study did not test the human health effects of coal-tar-sealant or PAHs in the Milwaukee area. PAHs do not easily accumulate within the food chain, so possible human-health risks associated with consumption of fish are low.”

Obviously, though, since the coal-tar sealants are used directly on parking lots, playgrounds, and driveways, people are directly exposed. The most common route of exposure would likely be dust contamination and inhalation.

Those interested in reading the full study can find it here.

 

Advertisement
 
Appreciate CleanTechnica’s originality? Consider becoming a CleanTechnica Member, Supporter, Technician, or Ambassador — or a patron on Patreon.
 
Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.

Written By

James Ayre's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy.

Comments

#1 most loved electric vehicle, solar energy, and battery news & analysis site in the world.

 

Support our work today!

Power CleanTechnica: $3/Month

Tesla News Solar News EV News Data Reports

Advertisement

Advertisement

Advertisement

Tesla News

EV Reviews

Home Efficiency

You May Also Like

Clean Power

Golden eagles, like many raptors, know how to take the path of least resistance. When they spread their wings and take to the skies,...

Clean Power

Bat Appreciation Day is April 17, and as we pause to admire these unique creatures, we also recognize that bats face many threats, including...

Batteries

Fossil energy stakeholders continue to cast doubt upon the power of renewable energy to transform the global economy, but their grip on reality is...

Air Quality

Originally published by Union of Concerned Scientists, The Equation. By Rachel Cleetus, Policy Director This week, the Union of Concerned Scientists, Earthjustice, and the Center for...

Copyright © 2021 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.