PHILADELPHIA (AP) - Pennsylvania is set to begin sampling drinking water across the state later this month in a bid to determine whether a class of highly toxic chemicals is contaminating the supply.
  
Department of Environmental Protection officials tell The Philadelphia Inquirer the plan is on track to start around the end of May.
  
The perfluoroalkyl and polyfluoroalkyl substances, known collectively as PFAS, have turned up increasingly in public water systems and private wells around the country.
  
To date, the state has identified 493 public water systems in Pennsylvania that are located within half a mile of a potential source of PFAS contamination.
  
PFAS contamination has closed drinking wells and caused health concerns in Bucks and Montgomery counties.
  
Scientific studies have found "associations" between the chemicals and cancer, thyroid disease, ulcerative colitis and other health issues.
  
___
  
Information from: The Philadelphia Inquirer, http://www.inquirer.com

(Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)