sing new detection techniques, researchers have found trace amounts of various medicinal substances in lakes and rivers. Taken i
n large quantities, these substances could have serious health effects, but they are present in quantities far too low to cause any physiological response in people who drink the water or bathe in it. Nevertheless, medical experts contend that eliminating these trace amounts from the water will have public health benefits, since __________.
Disease-causing bacteria exposed to low concentrations of certain medicinal substances can become resistant to them. this clearly mention how eliminating these substance will have health benefits.
