Twin Cities Daily Planet examines why Ramsey County last month received an F grade for particulate matter pollution on the American Lung Association's 2012 State of the Air report. Hennepin, Dakota and Scott counties all received a C grade.

The county's charter commission is holding the first of two public hearings on whether voters should get to approve a sales tax for the stadium.

Ramsey County Commissioners Tony Bennett and Rafael Ortega have requested a meeting with state lawmakers to discuss a new Vikings stadium proposal, which would include a countywide 3 percent food, beverage and liquor tax.

The number of delinquent taxpayers in Hennepin County has dropped, but more taxpayers are at risk of losing their properties to pay off their tax bills. Hundreds of property owners owe the county nearly $43 million in back taxes and penalties. The Star Tribune reports the county sent out a record 931 notices last year warning owners the deadline to redeem their properties was about to expire.

The Ramsey County Charter Commission voted late Tuesday to reject a countywide vote on a proposed half-cent sales tax that would help build a new home for the team. The move went against the wishes of many county residents, but leaders say it would have held up the project and raised its price tag.

The American Lung Association released its "State of the Air" report Wednesday and has given Ramsey County an "F" for "short-term particle pollution." That's down from a "B'' in 2009, a "C" in 2010 and a "D'' in 2011. Overall, Minnesota earned better grades for "high ozone days," but lower grades for "high particle pollution days."

Ramsey County leaders hope to collect 15,000 signatures to force a referendum vote in November on whether to publicly fund a proposed Arden Hills stadium. The ad hoc group says the effort is in response to elected officials ignoring their constituents and kowtowing to Vikings ownership.

Ramsey County Attorney John Choi says most of the sex trafficking and prostitution cases his office deals with start with the "adult services" ads found at Backpage.com. Choi says the site encourages sex trafficking of children. Prosecutors around the country are pushing for removal of the adult classifieds from the site. CNN profiled a St. Paul woman whose runaway daughter was prostituted through the site.