What are the toxicological effects of T(R)WP?
Click on any of these links to jump straight to that article: Pages: 1 2 3 4 5 6 7 8 9 10By far the best-known effect of tire particles is in Coho salmon and some trout species found in the pacific North-West of the United States. In these populations half – or even more – of fish returning to their spawning grounds die on the way, before they can reproduce.
Current research shows 6PPD-quinone is acutely toxic to Coho salmon and kills fish within a few hours after exposure.
6PPD is widely used in tires. When in the environment it oxidises to form a chemical known as 6PPD-Quinone. It turns out that this material is highly poisonous to some species of fish.
The California Department of Toxic Substances Control has categorised 6PPD-Quinone as ‘highly toxic’ and is preparing legislation to ban its use, or severely restrict usage.
A key research paper by Zhenyu Tian of the Center for Urban Waters in Washington State and others says, 6PPD-quinone “is among the most toxic chemicals known for aquatic organisms.” The researchers found that half the salmon die when exposed to approximately 0.1 parts per billion of 6PPD-Quinone. This, they said, makes 6PPD-quinone “among a very small group of pollutants, mostly organophosphate or organochlorine pesticides, with acute toxicity expectations at tens of nanograms per litre.”
The chemical was found to have leached out from tire particles present in the spawning streams. This is evidence that these tire particles cause damage to some eco-systems.
What is less clear is how much damage they cause to humans and to other species.
Although the evidence is not yet incontrovertible, it is growing. Traces of 6PPD-Q have been found in human urine and other microplastics have been found in human breast milk as well as human bloodstreams.
Larger particles tend to be ingested by creatures, pass through the gut in a few hours and emerge more or less unchanged at the other end.
However, smaller particles can be breathed to the lungs and when ingested, tend to lodge in the gut, where they remain. The question then arises is how the particles are affected by the gut environment which has adapted to extract chemicals from the food passing through the gut. There is a high probability that any chemicals present in the particles will leach out and potentially cross the gut barrier into the organism.
The effects of this are largely unknown, however, early evidence suggests that toxic chemicals do pass across the gut barrier, affecting the health of the organism.