20.02.2004

Tire toxicity Care tires are commonly made from rubber, but they also contain a lot of other ingredients, for example, textile fibres, oil and polycyclic aromatic hydrocarbons (PAHs). Especially during speed up and slow down maneuvers small particles are getting abrased at the tire/road boundary and released to air. Many PAHs are known human carcinogens, notably benz(a)pyrene. According to the German TV magazine "Kontraste" the German Federal Environmental Agency ("Umweltbundesamt"; UBA) has been researching this issue for some time. An UBA official confirmed (sic!) the toxicity of PAHs. BUT the study has not been published, yet, and there are several caveats before a risk estimate can be given: the travelling distance of rubber particles in air depends on several parameters (size, density, etc.) but we need to know the inner exposure to such particles; in order to act in the human body the toxic PAHs have to be released from the rubber/oil matrix of inhaled or ingested tire-derived particles. Nevertheless, exposure to traffic exhausts in the general German population is huge, and further research into this subject is badly needed. The TV magazine also cited a spokesperson of the German subsidiary of Nokian (a Finland-based car tire manufacturer) that the production of almost PAH-free tires is technically feasible without compromises in tire safety and performance. Interestingly, the EU commission has already decided to stop the use of PAH-releasing tires in the EU, but after heavy opposition from the tire industry that verdict will unlikely become effective before 2009. 11:23:47 PM