A co-worker is concerned about their exposure to estrogenic compounds in drinking water. You decide to calculate the risk to humans using the minimum therapeutic dose for estrogenic compounds, which is 1.5 mg/day. You determine that the concentration of estrogenic compounds in drinking water is 20ng/L, and the average person drinks 2 L of water per day. From this information, calculate the risk of an individual being exposed to a therapeutic dose of estrogenic compounds in drinking water. Ensure you show your calculations and explain what the resulting number means to your co-worker.