I am looking for a water quality expert/toxicologist to answer a few questions about chemicals used to treat public drinking water: 1. Are there any potential health concerns with chemicals typically used to treat public drinking water, such as chlorine etc.? 2. Research has found some evidence that water disinfection byproducts from chlorination may increase the risk of specific cancers. What are your thoughts on this? 3. While there are regulatory limits on disinfection byproducts, some people may be concerned about exposing themselves to any levels of chemicals. What can they do to reduce or eliminate these chemicals in their tap water?

Good Day, 1. Is there any health risk involved with the chemicals that are added for public drinking water treatment, such as chlorine? Yes. Chlorine is needed to kill harmful microbes; however, it reacts with natural substances in the water and forms disinfection by-products (DBPs) that, with long-term exposure, could pose potential health risks. Chlorine itself is typically in safe levels, while the by-products are the main problem. 2. Some studies have found evidence that water disinfection by-products from chlorination may increase the risks for certain cancers. What is your opinion on that? Long-term exposure to some DBPs, especially trihalomethanes (THMs), is fairly well linked to an increased risk of bladder cancer. The cancer risk posed is very small, yet so small as to give rise to strict regulatory limits aimed at balancing the benefits of disinfection against minimizing exposure to by-products. 3. Although there are regulatory limits for disinfection by-products, there may be those who do not want to expose themselves to any levels of chemicals. What can be done to reduce or eliminate these chemicals in their tap water? To minimize DBPs: Activated carbon filters (those used in pitchers or under-sink systems) are effective and easy to maintain. Reverse osmosis systems will give you much better filtration but are more expensive. Leaving it out uncovered will also allow chlorine gas to off-gas naturally. If you decide to use this quote, I'd love to stay connected! Feel free to reach me at gregorygasic@vmedx.com and outreach@vmedx.com.

Disinfectants, such as chlorine and chloramine, are important for keeping waterborne diseases away. Water companies use small amounts that protect public health. But these disinfectants can mix with natural stuff in the water and create other things called disinfection by products (DBPs). These DBPs are watched closely and regulated. The EPA and CDC have set limits and say the disinfectant levels used are usually safe. Studies suggest some groups of DBPs, like trihalomethanes (THMs) and haloacetic acids (HAAs), might increase the chance of bladder cancer with long term exposure. Agencies are still checking the facts and changing rules to lower how much people are exposed to these. But, this isn't a reason to skip disinfecting water. The possible risk from DBPs is smaller than the risk of not treating water for germs. If people want to cut down on DBPs and other chemicals, here are some simple things they can do: (1) use filters with granular activated carbon (GAC) or certified carbon block filters (they work for many THMs/HAAs), (2) use reverse osmosis systems (they remove a wider range of chemicals), and (3) let cold water run for a bit before using it, and use cold water for cooking (hot water can have more chemicals in it). Look for NSF/ANSI certifications that fit the chemicals you want to remove, and keep your systems maintained as instructed.