Friday, October 08, 2004

Okay, for the umpteenth time: the dose makes the poison!

The World Wildlife Fund have found lots of chemicals in children's blood. Unsurprising - there are lots of chemicals all around us. But trace amounts of chemicals do not necessarily (or even probably) cause any harm at all.

[A] spokesman for the Medical Research Council's Institute for Environment and Health in Leicester told BBC News Online: 'The world is composed of 'chemicals' and many of the most hazardous are natural.' He added that the presence of 'older' chemicals such as DDT in all age groups was not surprising as they were 'ubiquitous throughout the globe and very persistent' - which was why they were banned. He said: 'At first sight it is rather worrying that 'new' chemicals such as the brominated flame retardants are occurring at higher levels in the children. But we would need to see the rest of the data to assess the actual difference in levels and whether this is statistically and biologically significant.'

BBC NEWS | Health | Pollutants 'in children's blood'

Monday, October 04, 2004

Another plastic panic

'Household plastics to blame for asthma, say scientists', reported the Sunday Telegraph. A study by Swedish researchers examined the bedroom dust of almost 400 children, half of whom suffered from asthma or other allergic conditions. In the bedrooms of allergic condition sufferers the levels of phthalates (organic compounds frequently used to make plastics more flexible) were significantly higher than in the bedrooms of children not suffering such conditions.

'There are phthalates in so many different products that if we are right, then all of us are in real trouble', lead researcher Carl-Gustaf Bornehag said. 'The associations between asthma and phthalates are the strongest we have seen. We need more clinical studies.' The report follows hot on the heels of the decision by the European Union permanently to restrict the use of many phthalates.

While the differences found in this study may be statistically significant, it's not clear whether they are practically significant. The Sunday Telegraph states: 'For example, children who suffered from asthma had an average of 0.15mg of one variant of the chemical butyl benzyl phthalate in their bedroom dust...whereas bedrooms of children without allergies [had] only 0.12mg.' The figures for another substance, DEHP, were 0.9mg (associated with asthma) and 0.72mg (not associated with asthma). Why being exposed to a very small amount of these substances causes asthma but being exposed to a tiny bit less doesn't, is not made clear.

The EU restrictions on phthalates are not supported by scientific evidence, but rather came about as a result of campaigning by environmental groups. The EU commission's European Chemical Bureau published a risk assessment of one form of phthalates in 2003, saying: 'The end products containing DINP (clothes, building materials, toys and baby equipment) and the sources of exposure (car and public transport interiors, food and food packaging) are unlikely to pose a risk for consumers (adults, infants and newborns) following inhalation, skin contact and ingestion.' This risk assessment has been ignored by EU ministers, whose ban on phthalates has been described as 'a significant victory for the politics of emotionalism over reasoned debate'.

At present, a variety of different environmental factors have been implicated in causing asthma, including housing, diet and smoking - though none has been proven. Most importantly, asthma tends to run in families, suggesting a genetic component. And increases in asthma in recent years may have resulted from changes in diagnosis. There is much frustration at the inability to solve the problem of asthma. Finding one particular cause responsible for a large proportion of cases would be welcome - but scapegoating a harmless and versatile group of chemicals helps nobody.

Dust in children's bedrooms is a problem - but only for overworked parents desperate for their offspring to clean up once in a while.

Household plastics to blame for asthma, say scientists, Sunday Telegraph, 3 October 2004

Switzerland : EU bans toys made from chemicals, Fibre2Fashion, 28 September 2004

The compensation culture

Good to see primary school children being introduced to the idea that you should take ludicrous precautions or someone might sue you. They're playing the traditional British game of conkers, but being asked to wear eye protection. The headmaster is terrified that if someone puts their eye out, that the school will be sued. These are the same children who will then tear round a playground, scaping their knees and occasionally worse. Should children not be forced to wear padded safety suit when playing?

And then someone will complain that children are getting fat because they don't play enough. How can they, when any such activity is regarded as inherently dangerous?

BBC NEWS | England | Cumbria | Pupils wear goggles for conkers