asphalt sealants

Washington is first state in nation to ban toxic pavement sealants

OLYMPIA – Washington became the first state in the nation Thursday to ban toxic asphalt sealants made from cancer-causing industrial waste that have been spread over vast swaths of the nation’s cities and suburbs.

The toxic ingredients in coal tar-based sealants are turning up in ordinary house dust as well as in streams, lakes and other waterways at levels that concern government researchers.  The chemicals have been found in people’s driveways at concentrations that could require treatment by moon-suited environmental technicians if detected at similar levels at a toxic-waste cleanup site. The sealants are also applied on playgrounds and parking lots.

When Gov. Christine Gregoire signed the measure Thursday, Washington became the largest government to ban or restrict coal tar asphalt sealants. Last month, Prior Lake, Minn., joined a growing number of local governments to ban them.

Alternative, asphalt-based sealants, shed far fewer toxic particles, government tests show.

The Washington State legislation and a drive for a nationwide ban flowed from studies by the U.S. Geological Survey, which showed that components of the toxic sealants are increasing in many waterways, while levels of most other pollutants are declining. One study of 40 lakes nationwide conducted last year showed high levels of contamination in Lake Ballinger north of Seattle.

A 2009 Geological Survey study identified chemicals associated with the coal tar sealants in house dust at levels that worried researchers because they could contribute to longterm cancer risks, especially in young children who crawl around through – and might accidentally ingest – the toxic dust.

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