My wife and I took a night boat tour of a heavy industrial area in Kawasaki on August 17, 2017. It has become a popular tour that appeals to people for its blightly lit factories, an unexpected "beauty." We rode in a boat with no roof capable of taking 40 or so passengers. The tour started from a berth close to Haneda airport, then crossed the Tama River while watching jet airliners making their final approaches.
Our boat was small enough to navigate the canals one after another, allowing us to come closer to the big factories. Once, the area was infamous for environmental pollution, both air and water, it has become much cleaner thanks to strong anti-pollution measures that have been implemented. But surprisingly enough, I felt the air to be smoggy and the water smelled of pollution. Regardless, it was an interesting experience.