Are there extras in our drinking water?

Are chemicals, such as human hormones and pharmaceuticals, getting into Australian water supplies and creating possible health risks to the public? Researchers from the Cooperative Research Centre (CRC) for Water Quality and Treatment are holding an industry workshop in Melbourne giving an overview of recent studies attempting to provide answers to this question.

Called micropollutants because they are generally present at extremely low concentrations, these biologically active chemicals get into our wastewater, largely through human activity.

Examples include endocrine disrupting chemicals from natural estrogens, surfactants and pesticides, antibiotics excreted by humans or animals, or fragrances used in personal care products. Heavy metals in industrial effluent and disinfection by-products of chlorine used in water treatment can also affect biological systems. Internationally, particularly where sewage recycling is more common, there is continual re-assessment of what constitutes safe concentrations of different micropollutants.

The CRC has been investigating some micropollutant chemicals to determine if they pose any risk to drinking water quality in Australia. The fact that these chemicals are present in wastewater is a concern because of the potential use of recycled sewage for drinking water.

Results of CRC studies indicate that efficient sewage treatment can remove these micropollutants to very low concentrations and their presence in environmental waters is generally very low.

CRC researchers have been tackling this complex issue from a number of fronts to get a better idea of the potential risks of being exposed to varying levels of specific compounds. Epidemiologists compare groups of people who have already been exposed to a micropollutant with others who haven’t, to see if there are differences in general or specific health indicators.

Toxicologists look at the effects of micropollutants at a range of exposure levels on mammals such as rats, on human or mammal cells in culture, or on aquatic organisms such as algae or fish.

Measurement is critical in assessing risk because sensitive techniques that detect very low quantities of chemicals were not available even a few years ago. New bioassays can measure the combined effect of a mixture of chemicals at extremely low concentrations.

The Australian water industry and researchers are at the cutting edge in developing and adopting new techniques and information to ensure the safety of our drinking water.

Remaining workshop dates are: Adelaide 23 — October and Perth — 24 October.