Per- and poly-fluoroalkyl substances

Because of their widespread use, most people in Australia are expected to have some PFAS present in their body. Although there are many types of PFAS that exist, the most prevalent PFAS found in the Australian population to date have been perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and Perfluorohexane sulfonate (PFHxS).

PFAS exposure can occur from the air, indoor dust, food, water, and various consumer products. However, for most people ingestion of food and drinking water contaminated with PFAS is expected to be the primary source of exposure because PFAS are readily absorbed through the gut. Inhalation of dust contaminated with PFAS and dermal (skin) contact with PFAS, including from showering and bathing in contaminated recreation water, are minor exposure pathways.

Once these chemicals are in a person’s body it takes a long time for those levels to substantially reduce, even if no more is taken in. Depending on the type of PFAS, studies indicate that the time taken for the levels to reduce by half can be from 2 to 8 years.

For most people the level of exposure is likely to be relatively small and no public health and safety concerns in relation to PFAS have been identified for the general Australian population.

Some Australian communities near facilities where PFAS have been used, particularly as an active ingredient in AFFF used in firefighting, have higher levels of PFAS in the surrounding environment. In these communities, it is possible for people to have increased exposure to PFOS and PFHxS, particularly if they regularly consume bore water or certain locally grown food.

The estimated risks of PFAS at concentrations observed in the general community, including those in specific exposure areas, have generally been small; therefore, current exposure to PFAS is unlikely to lead to adverse health effects. However, there is still uncertainty and, internationally, research is still ongoing.

Studies relating to PFAS exposure, including worker exposures, has been associated with the following human health effects:

• increased levels of cholesterol in the blood
• increased levels of uric acid in the blood
• reduced kidney function
• alterations in some indicators of immune function
• altered levels of thyroid hormones and sex hormones
• later age for starting menstruation (periods) in girls, and earlier menopause
• lower birth weight in babies.

Potential associations between PFAS exposure and increased risk of two uncommon cancers, namely, testicular and kidney cancer have also been reported. Much of this evidence relates specifically to PFOA, and not PFOS or PFHxS which are more common in Australia. However, studies on these cancers remain conflicting and associations have only been observed in high exposure groups.

As a precaution, WA Health continues to recommend exposure to PFAS be minimised wherever possible. This precautionary advice considers the current scientific evidence, including the lack of causation data on human health effects and the ability of these chemicals to persist in humans and in the environment.

PFAS and the general food supply

Current evidence suggests PFAS levels in the general Australian food supply are very low and regulation of PFAS chemical contaminants in the general food supply is therefore not required. The Australian Government Department of Health and Aged Care has developed health-based guidance values, in the form of a tolerable daily intake (TDI), for PFOS, PFOA and PFHxS for use in site investigations across Australia.

A TDI is an estimate of the amount of a chemical, expressed on a body weight basis that can be ingested daily over a lifetime without appreciable health risk to the consumer. The TDI can then be used to work out safe guidance values of the chemicals in different types of items that people consume, such as food or drinking water.

FSANZ’s 27th Australian Total Diet Study, found PFAS levels in the general food supply are well below Australian guidance values. Estimated dietary exposure to PFOS for the general Australian population is well below the TDI. No other PFAS were detected in the study. This indicates that there are no public health and safety concerns in relation to PFAS from overall dietary exposure for the general Australian population.

Where PFAS contamination has been identified in a local area, people within these areas will be provided with specific advice around how to minimise their exposure. This local advice takes into consideration the Australian guidance values and specific local circumstances.

PFAS and drinking water supplies

To ensure safe drinking water and provide a basis for determining the quality of water to be supplied to consumers in all parts of Australia, the National Health and Medical Research Council (NHMRC) has developed the Australian Drinking Water Guidelines (2011) (external site). The Guidelines include maximum health-based guidance values for PFOS, PFOA and PFHxS in drinking water. These were published in 2018 and were derived using the TDI values recommended by the Australian Government Department of Health and Aged Care.

Reference values are used by scientists to determine the acceptance level of chemicals or substances. One way to express these values is through a Tolerable Daily Intake, often referred to as a (TDI). 

The TDI’s for PFAS are important for evaluating the exposure in communities around sites with contaminated drinking water and food. 

On 3 April 2017, the Australian Government Department of Health published final health based guidance values (external site) for use in site investigations across Australia for PFOS, PFOA and PFHxS.

The significant health benefits of breast feeding are well established and outweigh any potential health risks to an infant or child from the possibility of any PFAS being transferred through breast milk.

It is understandable that individuals living in PFAS affected communities may want to know what their level of exposure to PFAS is and what this means for their health and the health of their families.

A blood test can measure the level of PFAS in a person’s blood. If PFAS is detected, this tells a person that they have been exposed to PFAS. These results could then be compared with the levels seen in the general Australian population or in other countries using published biomonitoring data. However, there is at present insufficient scientific evidence for a medical practitioner to be able to tell a person whether their blood level will make them sick now or later in life, or if any current health problems are related to the PFAS levels found in their blood.

Therefore, blood tests are not recommended as they cannot determine whether any medical condition is attributable to exposure to PFAS and have no current value in informing clinical management, including diagnosis, treatment, or prognosis in terms of increased risk of particular conditions over time.

Therapeutic blood donation is where patients are advised to give blood for a known health benefit. Currently, there is no clinical evidence that decreasing PFAS levels in blood results in better health outcomes.

Given the value of blood donations generally, WA Health encourage anyone who can to consider donating, even if you live in an area where environmental PFAS concentrations are considered to be elevated.

Lifeblood, the organisation responsible for the collection and distribution of blood and related products in Australia, does not exclude people with higher than background PFAS blood levels from donating.