More Olympic athletes to compete in the Seine River, here’s the latest on water quality concerns

He compared it to looking at a busy road with pedestrians, motorcycles, cars and buses and trying to count all the people. The city’s method, he said, is similar to counting from a helicopter and weighing each person or vehicle equally, because you can’t see how many people are in each car or bus. He says his comprehensive test is more like a police officer stopping every vehicle and counting every person in the car or bus to get a full count.