How do pharmaceuticals enter and affect our water systems?

Pharmaceuticals enter our water systems through human and animal waste, and improper disposal, affecting aquatic life and potentially human health.

Pharmaceuticals, including prescription and over-the-counter drugs, can enter our water systems in several ways. The most common route is through the excretion of unmetabolised drugs by humans and animals. When we take medication, our bodies do not always fully metabolise or absorb it, and the remainder is excreted in urine or faeces. This waste then enters sewage systems and eventually reaches rivers, lakes, and groundwater.

Another significant source of pharmaceutical contamination is the improper disposal of unused or expired medication. Many people flush these drugs down the toilet or sink, or throw them in the bin, from where they can leach into groundwater. Hospitals and care homes, which use large quantities of medication, can also contribute to this problem if they do not dispose of their waste correctly.

Once in the water system, these pharmaceuticals can have a range of impacts. Aquatic organisms, such as fish and amphibians, are particularly vulnerable. Exposure to even low levels of drugs such as antidepressants, contraceptives, and antibiotics can affect their behaviour, reproduction, and growth. For example, studies have found that exposure to synthetic oestrogens from contraceptives can cause male fish to develop female characteristics.

There is also concern about the potential effects on human health. While water treatment processes can remove some pharmaceuticals, they are not designed to deal with this type of contamination and many drugs can still be detected in treated water. The long-term effects of exposure to these low levels of pharmaceuticals are not yet fully understood, but there is concern that it could contribute to problems such as antibiotic resistance.

In conclusion, the presence of pharmaceuticals in our water systems is a growing concern. It is a complex issue that requires a multi-faceted approach, including improved waste management, changes in prescribing practices, and the development of new water treatment technologies.