Huge amounts of antibiotics are consumed every year. In 1954, two million pounds of antibiotics were produced in the US. Today, that figure is more than 50 million . One statistic released by the FDA suggests that ~30 million pounds of antibiotics are used by livestock for growth promotion and prevention (prophylaxis) .
This massive usage of antibiotics is having a toll on the environment as residual antibiotics from human and animal use can enter the environment in many ways. The 3 primary ways are :
1) Wastewater effluent discharge
2) Human/animal waste run off from land