I'm looking forward to the water, to finally getting started. From the Black Forest to the Black Sea, for eight weeks, chemistry professor Andrea Spat will swim the entire（全部的） length of the Danube. 2700 kilometers running through ten countries, the Danube is the second longest river in Europe. Spat's mission（使命）? To combat（ 搏斗） plastic waste. Each day, four tons（吨） of microplastic from the Danube washes into the Black Sea.

  Spat plans to head there, braving the cold, storms and high waves. An adventure in the name of science. The media（媒体） have gathered by the Danube in Ulm for the start of his journey. A competitive swimmer all his life, Andrea Spat hopes the publicity（宣传） will draw attention to the plastic waste problem. If I weren't swimming, they wouldn't be here. This helps us spread the message, so hopefully things will change.

  Because plastic waste is everywhere. But his swim is a science project, too. Two chemists from his team will collect water samples all along the route, starting with the Bregach and Breg streams converge（聚合） to form the Danube. Here they filter（滤波器） 1,000 liters of water, looking for microplastics. Back in Ulm, here the Danube is a chilly（寒冷的） 12 degrees Celsius, thought is always accompanied（陪伴） by a kayak, not just due to the cold, but to ensure（保证） his safety, too. His wife is also on hand at the start.

  A team of eight organizes everything, from energy bars to speeches, while Andrea Spat swims. I don't have to do this, but it gives me more influence to change things. I want to do something meaningful（ 意味深长的） with my time on this planet. I want to use it sensibly, not just as a consumer. This is a positive contribution（ 贡献） I can make to protect bodies of water. And it's not completely selfless（无私的）, I admit, because I like to swim in open water, and preferably（ 更可取地） in clean water.

  But where does microplastic come from? How does it form? Like here in Günsburg, the team holds educational workshops（车间）, too. Spat rushes（冲） in to give talks, reciting the figures off by heart. Since 1950, when mass（群众的） production of plastic began, we've produced 8.3 billion tons of plastics. Of that, just 9% is recycled worldwide.

  Microplastics can breach（违反） the blood-brain barrier（(阻碍通道的)障碍物）. They accumulate（积聚） in the brain and weaken（削弱） our immune（免疫的） system, yet（但是） we ingest plastic daily, even from salt mills（磨坊）. It's not just salt that comes out, but tiny fragments（碎片） from the plastic. We put this in our food. Each week we ingest about a credit card's worth（价值） of microplastic, 5 grams. Tire wear is also a source of microplastics in the environment.

  Tire particles（颗粒） are washed from the streets into the sewers（下水道）, and from there to the rivers. Here, the brittle（ 易碎的） plastic in them is ground（磨(碎)） down further by rocks and the current（（水）. The team organizes cleanup sessions（会议） along the Danube, like here in Ingolstadt. Their schedule is packed, and Andreas Pfatt keeps giving interviews and forgetting how cold he is. A hot shower. Now that really helps.

  Especially when you're really frozen.