September 22, 2025
Overview:
Reliable data on how medicines are used across regions is essential for public health planning and management. Yet, such data is often missing in many parts of the world. This One Health Trust collaborative article explores whether measuring traces of medicines/active pharmaceutical ingredients (APIs) in untreated municipal wastewater can be used as a reliable method to estimate how much medicine people in a region are actually using.
The Question:
Could measuring traces of APIs in untreated municipal wastewater provide a reliable way to estimate regional medicine use?
The Findings:
Researchers examined 53 APIs in wastewater collected from 3 treatment plants in Stockholm, Sweden, between 2004 to 2021. They compared these measurements with comprehensive sales data from hospitals, pharmacies, and other outlets. By doing so, they calculated conversion factors such as how much of each drug found in wastewater corresponded to the amount sold.
They found that the amount of each medicine found in wastewater was usually the same or lower than what people were expected to be using (except for one medicine).
For most medicines, the results stayed fairly steady from year to year.
When the method was tested at another treatment plant, the estimates of medicine use were quite accurate, usually within about half or double the actual number for most medicines.
These estimates also matched well with results from studies done in other countries.
How well medicines are removed in treatment plants, or their chemical properties, didn’t explain the differences in results
The findings show that medicines in wastewater can provide reasonably accurate estimates of regional medicine use, typically within a two-fold margin of error. This approach could help fill critical gaps in health data worldwide.
Read the article published in the Environment International here.
