Intersexuality in the U.K. rivers and the James River is more than just an identity crisis for roachfish and catfish. Entire wildlife communities in rivers may be affected if species have trouble reproducing, deFur said. Some chemicals, like DDT, hang around so long they are passed through the food chain to birds, crabs, and maybe even people. These chemicals do damage in living things by acting like hormones, especially the estrogen type, and interacting with the hormone system. The chemicals may mimic natural hormones, block the operation of the real hormones, or act like a hormone but trigger an incorrect response from the body.
Hormones are the body's way of communicating messages about a wide range of functions.
The endocrine system sends the rest of the body hormonal instructions for how to control body growth, organ development, metabolism, and processes such as kidney function and body temperature, deFur said. In the U.S., most sewage treatment uses tertiary and quaternary processes to remove most of these compounds, but treatment in the U.K. doesn't usually reach that level, Tyler said. The U.S. also has more extensive waterways into which the sewage effluent can be dumped, allowing for better dilution. In Richmond, treated sewage effluent is released into the James River. The wastewater treatment plant in Richmond has tertiary treatment, which includes a series of sand filters, then chlorination to kill harmful microorganisms, Superintendent of Operations Clair Watson said.