Tuesday, November 3, 2009

Phthalates and PVC – the not good, the bad and the ADHD

At our last meeting, TTKD set up a packaging group to encourage companies to use less packaging, recyclable packaging and as this post will detail, non-toxic packaging. The case in point being the presence of Phthalates in PVC plastic.

Phthalates are added to some Polyvinylchloride (PVC and no.3 plastic) to make it more flexible and soft. However the phthalte molecules are not bound to the PVC and are able to leach or evaporate out. Some products made from PVC include food packaging, vinyl flooring, children's chew toys, pacifiers and children’s bottles.

Phthalates are also found in a wide range of other products (see the Wikipedia page of phthalates for an overview). While daily exposure to phthalates from a single product may be quite low (1), exposure to all the phthlalates that find their way into indoor air, foods, dust etc, from the many products containing phthalates, means the cumulative daily dose may exceed the safe maximum daily intake. Eg: In one study it was found that the "tolerable intake of children is exceeded to a considerable degree, in some instances up to 20-fold" (2).

Phthalates are endocrine disruptors, which essentially means they are reproductive and developmental toxins. Exposure to phthalates has been linked to a number of different adverse effects including:

Autism in children (3).
Asthma and allergies in children (4).
ADHD in children (5).
Obesity (6).
Abnormal sexual development due to prenatal exposure in males and because of this effect phthlates have been linked (along with other toxins) to the observed decrease in male fertility (7).

While many of these studies are very recent and need to be replicated they show a growing concern about the safety of phthalates and how they might “synergise” with other endocrine disruptors to cause significant deleterious health effects. Countries are now putting bans or limits on phthalates because of this and it would be sensible at an individual level to avoid products containing phthalates, which brings us back to PVC.

Currently PVC products are not marked at to whether or not they contain phthalates, meaning all Plasticized PVC (PPVC or just PVC) should be assumed to contain them and should be avoided.

So to summarise, products containing phthlates (of which PVC is one) are not safe, with children (both post-natal and pre-natal) being most sensitive to their deleterious effects. Because of this household use of PVC (no.3 plastic) should be avoided.

References (click to expand)

(1) Corea-Téllez KS et al 2008 Estimated risks of water and saliva contamination by phthalate diffusion from plasticized polyvinyl chloride. J Environ Health.
(2) Heudorf et al 2007. Phthalates: toxicology and exposure. Int J Hyg Environ Health.
(3) Larsson et al 2009. Associations between indoor environmental factors and parental-reported autistic spectrum disorders in children 6-8 years of age. Neurotoxicology.
(4) Jaakkola et al 2008. The role of exposure to phthalates from polyvinyl chloride products in the development of asthma and allergies: a systematic review and meta-analysis. Environ Health Perspect.
(5) Kim et al 2009. Phthalates Exposure and Attention-Deficit/Hyperactivity Disorder in School-Age Children. Biol Psychiatry.
(6) Desvergne et al 2009. PPAR-mediated activity of phthalates: A link to the obesity epidemic? Mol Cell Endocrinol.
(7) Hu et al 2009. Phthalate-induced testicular dysgenesis syndrome: Leydig cell influence. Trends Endocrinol Metab.

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