Safe Drinking Water Act 2011 and Safe Drinking Water Regulations 2012 - for providers of safe drinking water and guide for use of recycled water
Chlorinated solvents in groundwater
Chlorinated solvents are industrial chemicals used widely for metal cleaning and in production of thermoplastics, lacquers, perfumes and polyvinylchloride (PVC) products. Common chlorinated solvents include:
- tetrachloroethene (PCE)
- trichloroethene (TCE), also known as trichloroethylene
- dichloroethene (DCE)
- vinyl chloride.
In the past, PCE and TCE were used in dry-cleaning, while TCE was also used in many other applications including removing caffeine from coffee beans in the production of decaffeinated coffee and as an anaesthetic gas in hospitals.
The breakdown of chlorinated solvents in the body or in the environment
If chlorinated solvents are taken into the body, they are metabolised (broken down) and eliminated from the body within days.
In the environment chlorinated solvents break down rapidly in air and surface water but much slower in soil and groundwater.
PCE breaks down to form TCE; this in turn forms DCE and vinyl chloride which can then degrade to other chemicals.
How chlorinated solvents get into the groundwater
Past industrial practices allowed the discarding of contaminated solvents onto the ground. It was assumed at the time the solvents would evaporate, but much of the solvent leached into the soil. Adelaide has very shallow groundwater. This means that chemicals in the soil will often meet the groundwater (water that is held underground in layers of sand, or between layers of clay or rock) and contaminate it. Some solvents will float on top of the water while others will sink to lie beneath it. In all cases small amounts of the chemical will mix into the water.
If you suspect your bore is contaminated, see the Bore water quality testing page for more information.
Exposure through contaminated water
Exposure to chlorinated solvents from groundwater can occur if contaminated groundwater is brought to the surface using pumps on bores. Exposure to the solvents will occur if the contaminated groundwater is:
- used in cooking
- used in showers or swimming pools
- watering gardens
If sufficient levels are present and groundwater is shallow, chlorinated solvent vapours can also move upwards from the water and penetrate though the soil, building foundations and underground service infrastructure and contaminate indoor air. This is called vapour intrusion.
See the Testing bore water quality page for information on when to test and what to consider when testing bore water.
Exposure to these chemicals can also occur in our everyday life. These types of exposures are referred to as “background exposures” as they are unlikely to harm anyone. Background exposures include:
- tobacco smoke (vinyl chloride)
- household products including paint and spot removers (TCE)
- perfumes, lacquers and some plastics (DCE)
As exposures to chemicals occur from many sources in our everyday life, it is important that when there is an opportunity to reduce or prevent exposure that action should be taken.
Effects of chlorinated solvents on your health
The effects on your health depend on a number of factors such as:
- how long you have been exposed to the chemicals
- the level of chemical in air or water
- how old you are - young and elderly people are more vulnerable to adverse effects
- other illnesses you may have.
PCE or TCE
Inhaling or ingesting large amounts of PCE or TCE over short periods of time (minutes or hours) may make you dizzy or sleepy. This may occur if using the chemical with inadequate ventilation or personal protection equipment.
Inhaling low levels of TCE of many years may harm the central nervous system, kidney, liver, immune system or male reproductive system.
The International Agency for Research on Cancer (IARC) states that PCE and TCE are reasonably anticipated to cause cancer in humans.
If large amounts of DCE in air are inhaled over short periods of time (minutes or hours), you may feel nauseous, drowsy and tired. This may occur if using the chemical with inadequate ventilation or personal protection equipment.
Inhaling large amounts of DCE over long periods (years) may damage your liver and lungs.
It has not been determined if DCE causes cancer in animals or humans.
Breathing high levels of vinyl chloride over short periods (minutes or hours) can make you dizzy or sleepy.
If vinyl chloride is inhaled for long periods of time at high levels, it can cause effects on liver, kidney, nerve and immune functions.
The IRAC states that vinyl chloride is known to cause cancer in humans.
For further information on chlorinated solvents, contact SA Health's Scientific Services.