Toxic ingredients in coal tar-based sealants used in residential driveways enter the home and neighbor homes in dangerous concentration as dust. It's also found in streams, lakes and other waterways at levels that concern government researchers. Polycyclic aromatic hydrocarbons (PAHs) dust from coal-tar sealants on parking lots can contain hundreds or thousands of times the concentration of toxic chemicals as dust from parking lots using the asphalt-based products, federal scientists said. These sealants are also applied on playgrounds and parking lots, a danger to all but especially young children.

Coal tar is a known human carcinogen. It caused scrotal cancer in London chimney sweeps in the 1700s and skin cancer in creosote workers in this country a century ago. Children exposed to these chemicals in the womb may be more prone to asthma and other health problems and may suffer from lowered IQs, scientific evidence suggests. In men they can harm sperm and in pregnant women they can cause damage to the umbilical cord.

Installations flake away and enter the water stream in significant quantity. In streams, the chemicals have been shown to kill tadpoles, cause tumors on fish, stunt growth of aquatic creatures and reduce the number of species able to live in a waterway.

Alternative, asphalt-based sealants, shed far fewer toxic particles, government tests show, and only cost slightly more. Since an alternative is available, we want to see a ban on this known health risk.