Pollution and trash from the Tijuana River Valley have impacted the San Diego-Tijuana border region for decades. New research shows that it's not just the water that's affected. Toxic materials are also degrading the region’s air quality.A panel of environment reporters in the San Diego-Tijuana region joins us to talk about the origins of the cross-border sewage crisis. How did it all start? We look into the Tijuana River Valley’s eco-history — and how its water and air came to be polluted.Then, a look ahead to the Major League Baseball playoffs. The Padres are set to face the Chicago Cubs in the wildcard round on Tuesday. This weekend will determine where the series begins — it’s looking like Chicago, but there's still a chance it could come to Petco Park.Padres beat writer AJ Cassavell says this will be the first time these two teams have met in the playoffs since 1984.And finally, our weekly roundup of other stories from the week.Guests:Tammy Murga, environmental reporter, KPBSMackenzie Elmer, environment and energy reporter, Voice of San DiegoPhilip Salata, environment reporter, inewsourceAJ Cassavell, writer, PadresAndrew Bowen, metro reporter, KPBSJulianna Domingo, producer, KPBS