Of Flame Retardants, Autism and Skepticism
Last October some scientists got together in San Antonio to discuss the potential hazards of flame retardants. They wound up signing the "San Antonio Statement on Brominated and Chlorinated Flame Retardants" co-authored by Ake Bergman. Their claim is that the flame retardants are bio-persistent, toxic (especially when burned), cause neurological development in children and, because of their use in electronics including housings, being effectively dumped in third world countries where the products are recycled.
Bergman was interviewed for The Researcher's Perspective and you can read or listen to the interview at EHP in "The San Antonio Statement, with Ake Bergman". Bergman is quoted as saying of flame retardants "they are acting in a similar way than [sic] the other chlorinated compounds are, which is leading to a number of effects - for example, cancer risks; endocrine-disrupting properties of the chemicals, we have reproductive effects of the chemicals; and not the least, the neurodevelopmental effects that they cause, and for the neurodevelopmental we are talking about young children, the newborns, being affected." He goes on to say that he hopes that five years hence such flame retardants will all be banned and he says that "it's ridiculous to learn that you have nursing pillows with flame retardants..." Pity the poor maker of nursing pillows. A dropped cigarette or a pillow set too close to a space heater and woe be to the manufacturer who made it of cotton and didn't soak it in flame retardants.
Anyway, what should we make of the claim of neurodevelopmental effects? Well, as fate, or luck, would have it Dr Bergman has just co-authored a newly published study titled "Polybrominated Diphenyl Ethers in Relation to Autism and Developmental Delay: A Case-Control Study". The data from the study show that there is no relationship between PBDEs (the flame retardants at issue) and autism. In fact, the researchers managed to find that children suffering from neurological development delay were the ones with the lowest exposures to flame retardants.
So what did the researchers have to say about these findings? See pages 16 - 20 of the paper. Rather than simply reporting "we found no association between neurological development and exposure to flame retardants" the authors spend five pages saying why their exposure data is probably wrong and why even more studies of flame retardants and neurological development are needed.
Wouldn't it be nice, just once, if a scientist found an association between a chemical and some hot button disease and she spent her entire Discussion and Conclusion pointing out the reasons not to panic and not to jump to conclusions? That it doesn't happen when associations are found but does happen when the null hypothesis is confirmed says it all.
