A study by University of California researchers reported a significant association between household use of paint and childhood leukaemia-currently the most common type of cancer afflicting children around the world. Specifically, children exposed to paint in the home had a 65-per-cent greater risk of acute lympho-blastic leukaemia (ALL). As the risk rose with frequency of paint use, a causal relationship is suggested.
The more worrying aspect of these findings was that mothers who used paint during either preconception or pregnancy were up to three times more likely to have a child with ALL than were non-users. This means that paint may cause problems early on in the development of the fetus.
The researchers concluded that "avoiding the use of paint in the house during pregnancy and early childhood would be a prudent measure" (Environ Health Perspect, 2009; 117: 133-9).
These data add to the already convincing body of evidence linking paint and cancer. Indeed, a large-scale study conducted in 2001 found a significant dose-response relation-ship between the risk of ALL and the number of rooms painted in the house in the year before and year after the child's birth (Am J Public Health, 2001; 91: 564-7).
Other studies have found an association between childhood leuk-aemia and maternal occupational exposure to paint during pregnancy (Cancer Epidemiol Biomarkers Prev, 1999; 8: 783-91; Cancer Res, 1989; 49: 4030-7; Am J Epidemiol, 1985; 121: 216-24). In a large-scale case-control study by the US Children's Cancer Group, women who worked with paints or thinners while pregnant were nearly twice as likely to have a child with ALL. And again, paint/thinner exposure during the preconception period further increased the risk (Cancer Epidemiol Biomarkers Prev, 1999; 8: 783-91).
Other cancers are also linked to paint. Studies of workers in the painting trades and paint-making industry show higher rates of risk for cancers of the bladder, lung, larynx, pancreas, oral cavity, oesophagus, liver and stomach (J Occup Environ Med, 2002; 44: 258-64; Cancer Detect Prev, 1998; 22: 533-9). These findings are consis-tent with the decision of the International Agency for Research on Cancer (IARC) to classify painting as an occupationally related cause of cancer (Lancet Oncol, 2007; 8: 1065-6).
What's wrong with paint?
Conventional paint uses a cocktail of hazardous chemicals, so it's difficult to pinpoint the particular cancer-causing culprit. However, those iden-tified so far are chemicals known as 'volatile organic compounds' (VOCs).
Derived from petrochemicals, VOCs readily release vapours at room temperature. Although this 'outgas-sing' mostly occurs within the first few days, it can continue for months or even years after painting, seriously affecting indoor air quality (Int Arch Occup Environ Health, 1997; 69: 115-24).
For most people, the worst they'll suffer from VOC outgassing are head-aches and maybe dizziness or drow-siness. But VOCs may also be causing the increased risk of cancer seen in those frequently exposed to paint. Indeed, a number of VOCs in paint, such as benzene and formaldehyde, are known carcinogens (Environ Health Perspect, 1996; 104 Suppl 6: 1289-92; www. epa.gov/iaq/voc.html), and some are link-ed with higher rates of cancer in humans (Rev Environ Health, 2007; 22: 39-55; Cancer Causes Control, 1997; 8: 406-19).
But cancer isn't the only health problem related to VOCs. A study of more than 2000 UK men found that those regularly exposed to VOCs-especially glycol ethers, solvents commonly found in water-soluble paints-were more likely to have low motile-sperm counts, a significant predictor of infertility, compared with those not exposed.
In men who had particularly high exposures to glycol ethers, such as painters and decorators, the risk of abnormal sperm motility was more than doubled, leading the authors to conclude that these chemicals are a hazard to male fertility (Occup Environ Med, 2008; 65: 708-14).
In fact, previous exposure to glycol ethers-especially those in use from the 1960s until recently-continue to "have long-lasting negative effects on human semen quality" (Occup Environ Med, 2007; 64: 467-73). Shipyard painters exposed to two types of glycol ethers-2-ethoxyethanol and 2-methoxyethanol-had lower sperm counts and greater prevalences of oligospermia (low semen volume) and azoospermia (complete absence of sperm in the semen), findings consistent with earlier animal studies (Am J Ind Med, 1988; 14: 509-26).
Other paint VOCs-such as the 'aromatic' solvents toluene and xylene-may also have adverse effects on human reproduction (Occup Environ Med, 2001; 58: 635-40; Fertil Steril, 1999; 71: 690-6).
VOCs all around us
It's now confirmed that the levels of several common VOCs are, on average, two to five times higher indoors than outdoors, and the ever-increasing air-tightness of newer housing is very likely making the problem worse. A 2004 survey of people living in newly built homes found a significant correlation between the amount of VOCs indoors, and throat and respiratory symptoms, even at "relatively low" VOC levels (Int Arch Occup Environ Health, 2004; 77: 461-70).
Recent painting significantly contributes to household VOC levels, and is linked to asthma, and other respiratory and allergic effects, particularly in children (Int ArchOccup Environ Health, 1997; 69: 115-24; Indoor Air, 2007; 17: 259-77; Am J Public Health, 2004; 94: 560-2). As the California Environmental Protection Agency's Office of Environmental Health Hazard Assessment (OEHHA) has pointed out, children are more susceptible to VOCs because they are still developing physically. They also breathe at higher rates than adults do, resulting in their having higher relative doses of pollutants than adults have with exposure to the same air concentrations (see www. oehha.org/public_info/facts/airkids.html for more information).
VOCs also have negative effectson the state of the environment. At ground level, VOCs react with sunlight and oxygen to form a chemical smog, a problem evident in most major urban areas. Although the main culprits in cities are vehicular exhausts, paints certainly contribute to some extent. In fact, up to 5 per cent of environmental VOCs are from paints and varnishes, according to the 2000 European report Technology Guidelines for Vehicle Refinishes by the Brussels-based CEPE (Conseil Europ'een de l'Industrie des Peintures, des Encres, d'Imprimerie et des Couleurs d'Art; European Advisory for the Painters, Inks, Printers and Art Colours Industry).
Far worse, however, is the impact of VOCs on the earth's atmosphere. According to the European Science Foundation's VOCBAS (Volatile Or-ganic Compounds in the Biosphere- Atmosphere System) programme, not only do these chemicals contribute to the greenhouse effect, but they also damage the earth's protective ozone layer (see www.esf.org/vocbas for the latest information and updates for this ongoing research).
EU regulators have set maximum limits for these chemicals in paints and varnishes. However, even the more stringent limits, due to come into force in 2010, will permit up to 700 g/L of VOCs in certain indoor paints (for more details, see www.opsi.gov.uk/si/si2005/20052773.htm). In contrast, in the US, 350 g/L is the maximum permissible level.
So, the best you're likely to get from conventional manufacturers are paints labelled 'low-VOC' or 'low odour', which can still contain significant amounts (Indoor Air, 1999; 9: 253-8). Also, to reduce the VOCs in paint, some manufacturers may be replacing them with other, equally toxic ingredients.
Happily, there are safer options (see box on left). A number of small, independent manufacturers across Europe and the US now offer paints that use traditional non-toxic ingre-dients, including the natural dyes and pigments historically used by artists.
The downside is that they come in a more limited range of colours than doconventional paints. However, when it comes to our health and the environment, this seems like a sacrifice well worth making.
Painting more safely indoors
- Schedule painting for dry periods in the summer, when you can leave windows open for ventilation (2-3 days)
- Never use exterior paints indoors
- Take frequent fresh-air breaks while painting
- Watch out for tell-tale symptoms like watery eyes, headache, dizziness or breathing problems.
What about lead?
Modern household paints don't contain added lead, but old housing is still decorated with lead-containing paint, especially in Europe.
According to the UK's Department for Environment, Food and Rural Affairs (DEFRA), if your home was built before the 1960s and still has original coats of paint, there could be some lead around. Another 'red flag' is if your paintwork is thick, as lead could be locked within the older layers.
Lead paintwork can pose a problem when it's chipped or scratched, as this can release harmful lead dust into your home. The easiest way to deal with this is to seal it all in with an overcoating of modern, lead-free, non-toxic paint (see box below), but if the paint's in bad condition, it really needs to be removed. Use methods that don't create dust or fumes, such as solvent-free, water-based paint removers (see www.defra.gov.uk/ Environment/chemicals/lead/index.htm for more information).
In 2006, WDDTY's sister publi-cation PROOF! tested five leading alternative paint manufacturers for colour, coverage, texture, odour and quality of finish. Here's how they scored (out of five stars):
Tel: 01452 772 020
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Tel: 01452 770 629Rating: **