There are persistent concerns as to its safety, particularly for those who are regularly exposed to it. Research shows that it can cause a laundry list of adverse health effects-from headaches and dizziness to cancer and liver damage.
Dry cleaning is thought to have originatedin France, in 1845, when dye-works own-er Jean-Baptiste Jolly accidentally spilled lamp oil (kerosene, a petroleum-based solvent) on a soiled tablecloth. When the tablecloth dried, the stain was gone. Jolly is credited with coiningthe term 'dry cleaning' to differentiate it from 'wet cleaning'-soap-and-water washing. He then went on to create a firm, Jolly-Belin, that was Europe's first professional dry-cleaning service, cleaning other people's clothes using solvents instead of water.
Since then, a wide range of solvents have been used for the process of dry cleaning-from the highly flammable kerosene to the ozone-eroding green-house gas CFC (chlorofluorocarbon)-113. However, for the past 50 years, the most popular dry-cleaning agent world-wide has been perchloroethylene, or perc. It's considered ideal because it's non-flammable, gentle to most fabrics and an excellent cleaner.
But while the chemical may work wonders on your clothes, perc may be extremely hazardous to your health. There's growing evidence that expo-sure to perc can cause neurological, liver and kidney damage as well as increase the risk of cancer. It also contaminates the air, food and water. Many countries have now imposed stringent regulations for the controlof perc exposures and emissions. But are they enough?
In the latest report on perc-related health effects, a team of scientists at New York City's Columbia University made a shocking discovery: that exposure to perc can increase the risk of schizophrenia by 200-300 per cent (Schizophr Res, 2007; 90: 251-4).
The study examined the relationship between parental occupation as a dry cleaner and the risk for schizophrenia in their children. The researchers looked at a total of nearly 89,000 children born in Jerusalem from 1964 through 1976, and followed them from birth to 21-33 years of age.
Out of 144 dry cleaning families, there were four cases of schizo-phrenia-a much higher incidence than expected within the general population. The researchers attributed this increased risk to perc exposure, concluding that the chemical "warrants further investigation as a risk factor for schizophrenia".
Although further studies need to be carried out to verify this particular link, it has been known for some time that perc can have adverse effects on the brain. Since the 1970s, clinical studies have shown that exposure to perc can cause neurobehavioural problems-those related to emotion, behaviour and learning. This may be due to the depressive effect of percon the activity of the central nervous system, which relays messages to and from the brain to all other parts ofthe body. The resultant symptoms can range from mild to serious, depending on the level of exposure.
It's also been shown that long-term exposure to airborne perc-as shown by studies involving dry-cleaning workers and people living near dry-cleaning facilities in Germany, for example-can have a negative impact on neurobehavioural functions such as visual colour discrimination and rapid visual-information processing (Environ Res, 1995; 69: 83-9). In this case, the chemical/air concentrations were elatively low (1.36 mg/m3), yet even this amount of exposure affected those exposed for several years.
In another German study of acute perc exposure, visual and contrast-perception problems were surprsingly observed even at low inhalation levels of 50 ppm (parts per million) (Int Arch Occup Environ Health, 1990; 62: 493-9).
Similarly, a more recent study in New York City compared six residential families and the workers at a day-care centre in two apartment buildings that had dry-cleaning facilities on the ground floors. Compared with matched controls, those exposed to airborne perc, despite being healthy, performed poorly on tests of colour vision, per-ceptual speed, and sensory-motor and cognitive functions. They were also more likely to suffer from central-nervous-system symptoms (Environ Health Perspect, 2002; 110: 655-64).
Short-term exposure (less than 14 days) can cause dizziness, headache, lightheadedness, poor balance, visual impairment, reduced test scores and reaction time, and attention-deficit and eye-hand coordination problems (Townsend Lett Docs, 2007; June: 29-31).
Other toxic side-effects
As well as targeting the central nervous system, perc can also cause damageto the kidneys and liver-whether at extremely high doses over the short term or at low levels over the long term (Am J Ind Med, 1991; 20: 601-14; Townsend Lett Docs, 2007; June: 29-31; WHO Regional Office for Europe. Ch 5.13 Tetrachloroethylene, in Air Quality Guidelines, 2nd edn. Copenhagen, 2000). In one Italian study, changes in various markers suggestive of diffuse kidney abnormalities were evident in dry-cleaning workers exposed to very low levels (15 ppm) of perc (Lancet, 1992; 340: 189-93).
Even more worrying, occupational exposure to perc has been linked to reproductive problems, including spontaneous abortion, menstrual and sperm disorders, and reduced fertility (Townsend Lett Docs, 2007; June: 29-31). There's also evidence of birth defects when women are exposed to perc during pregnancy (Toxicol Ind Health, 2002; 18: 91-106; Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Tetrachloroethylene (Update). US Public Health Service, US Department of Health and Human Services, Atlanta, GA, 1997).
Yet another concern is that perc exposure may increase the risk of cancer. According to a US Environ-mental Protection Agency (EPA) fact sheet, studies of dry-cleaning workers exposed to perc and other solvents suggest an increased risk for cancersof the oesophagus, kidney, bladder, lung, pancreas and cervix (www.epa. gov/ttn/atw/hlthef/tet-ethy.html). These data, along with evidence from animal studies, led the International Agency for Research on Cancer (IARC) to classify perc as a Group 2A substance, one that is "probably carcinogenic to humans".
While those who are occupationally exposed to perc are especially vul-nerable to its carcinogenic effects, the general public is also at risk. A 1996 analysis by Consumer Reports found that one out of 6700 people wearing freshly dry-cleaned clothes once a week could be expected to develop cancer
as a result of inhaling the perc fumes clinging to the fabric (Townsend Lett Docs, 2007; June: 29-31).
As evidence accumulates as regards perc's health and environmental risks, many countries are placing more and more restrictions (and fines) on dry-cleaning businesses. In the US, the state of California has announced a statewide ban on toxic dry-cleaning chemicals and equipment, to be in place by 2023. As a result, a numberof cleaning firms are already offering safer alternatives to perc.
One increasingly popular option in the US and UK is silicone-based siloxane D5, better known as 'Green-Earth'. This solvent degrades to sand, water and carbon dioxide, and poses no health risks to workers, at least according to the GreenEarth website (www.greenearthcleaning.com). How-ever, siloxane solvents are made using chlorine, which may release dioxins-cancer-causing environmental pollu-tants-into the air. Siloxane is also highly flammable and "may be a can-cer hazard", according to the EPA (Townsend Lett Docs, 2007; July: 54-60).
Another option is liquid carbon dioxide (CO2), which has no reported health effects and came top in a review of alternative cleaning methods by Consumer Reports. Also, it produced better results than conventional perc cleaning. And cleaning with CO2 doesn't add to global warming because it's captured from industrial and agri-cultural emissions. However, the detergents used in the process contain volatile organic compounds (VOCs), some of which are toxic and/or car-cinogenic, and contribute to ground-level ozone.
By far, the safest cleaning alterna-tive is wet cleaning, which uses waterin specialized machines along with specially formulated detergents and additives. The process is one of the two methods considered environmentally preferable by the EPA (the other is CO2). Nevertheless, wet cleaning may not be suitable for all garments, and how your clothes turn out depends on the skill of the workers. But, at least, you aren't putting your health at risk.
The perc around us
Exposure to perc can come from eating contaminated food or drinking contaminated water but, for most people, exposure comes from breathing in the chemical from the air. After entering the lungs, it enters the blood-stream and then the rest of the body. Some of it may be stored in fat, liver and brain tissues for several weeks.
Perc exposure can also occur via the skin. In some places, this may be from contaminated soil, but the average consumer is most likely to be contaminated by dry-cleaned clothing.
Although dry-cleaning workers probably have the greatest exposure, living in close proximity to a dry-cleaning establishment can also put youat risk (see main text). Samples of breath, urine, blood and breast milk in people living above dry-cleaning shops also revealed the presence of the chemical. Moreover, high levels of perc were found in butter and other fatty foods sold in convenience shops located next to dry-cleaning facilities (Townsend Lett Docs, 2007; June: 29-31).
As well as being used as a dry-cleaning solvent, perc can also be found in other consumer products such as paint and spot removers, water repellents, brake and wood cleaners, glues and suede protectors.
Minimizing your risk
- If your dry-cleaned items have a strong chemical smell when you pick them up, don't accept them until they have been properly dried.
- If your items are returned to you with a chemical odour on subsequent visits, find a different dry cleaner.
- Remove the plastic wrapping and hang the dry-cleaned garments in a garage or covered porch for a few days to allow volatile solvents to dissipate.
- Avoid purchasing 'dry clean only' clothing.
- Some items labelled 'dry clean only' can be handwashed using special detergents such as Woolite.
- Use a clothes brush or spot-clean your clothing to freshen them up.