I’ve been trying to find information about chlorinated water and the immune system. I only drink minimal amounts of tap water at the moment. Apparently chloramine (a mix of cholrine and ammonia) is used in the water here, which is harder to boil off than chlorine.
Still, some tangential research suggests cause for concern. A 1987 Toxicology study found that consumption of water with even fairly low levels of monochloramine, a commonly used disinfectant that persists in drinking water longer than chlorine, disrupted the immune systems of rats—a finding that’s notable given the strong link between the human immune system and gut microbes.
From the study, which appears to be talking about high doses:
These results extend the earlier observations of others that macrophage function of laboratory rodents may be impaired by exposure to high concentrations of chlorinated drinking water. Furthermore, the function of other major populations of immunocytes and types of immune responses may also be altered following subchronic exposure to high concentrations of chlorinated drinking water. These types of effects on the immune system are a previously unrecognized potential side-effect of the ubiquitous practice of disinfection of water with chlorine compounds. Alteration of immune function of chlorine-based disinfectant-exposed rats in this study was only evident at relatively high doses, and only selected immune responses were altered. It appears, therefore, that these chlorine-based disinfectants are not particularly strong immunodepressants. However, further studies in different species may be warranted in order to better extrapolate to implications to human health following chronic low-level exposure.
It’s difficult to find information that is not from random blogs.