Ep 2. The Secret Science of Sewage

In this episode of Horizon, entitled "The Secret Science of Sewage," viewers are taken on a journey through the world of wastewater treatment. Despite the lowly reputation of sewage, it turns out that the water we flush down the toilet is a treasure trove of useful information about ourselves, our health, and our environment.

The episode begins with a trip to a sewage treatment plant, where we meet the scientists and engineers who are responsible for turning our waste into clean, safe water. We learn about the various stages of treatment, from the initial screening and settling of solids to the biological and chemical processes that remove pollutants and pathogens. Along the way, we discover some surprising facts about the composition of sewage and the challenges involved in treating it.

But the real focus of the episode is on the cutting-edge science being done with sewage. We meet researchers who are using sewage as a tool for monitoring public health, tracking disease outbreaks, and even detecting the presence of drugs and pollutants in the environment. We learn how viruses and other pathogens can be detected in sewage samples before they cause large-scale outbreaks, and how communities around the world are using this information to prepare for and prevent the spread of disease.

The episode also explores the role of sewage in the emerging field of "wastewater epidemiology." By studying the levels of viral RNA, bacteria, and other biomarkers in sewage, researchers can get early warning of outbreaks of diseases such as COVID-19, polio, or even Ebola. We see how this technique is already being used around the world to track the spread of COVID-19, and how it might be applied to other infectious diseases in the future.

In addition to its role as a tool for public health, sewage also provides a wealth of information about our environment. By analyzing the levels of chemicals and other contaminants in sewage, scientists can track the presence and distribution of pesticides, plastics, and other pollutants in our waterways. We learn how this information is being used to guide efforts to reduce pollution and protect our remaining freshwater resources.

Throughout the episode, we meet a variety of researchers, engineers, and public health officials who are working to harness the power of sewage. We learn about the challenges they face, both technical and political, as they try to turn sewage into a valuable resource. And we see how their efforts are already making a difference in the fight against disease and pollution.

In the end, "The Secret Science of Sewage" reveals sewage to be not just a waste product, but a vital source of information that can help us better understand ourselves and the world we live in. It is a fascinating, eye-opening exploration of an often-overlooked corner of science, and a reminder that even the humblest of substances can hold great secrets.